glider battery duration problems

[John Marshall]

I need advice about the best choice of batteries for an asg 29e. lithium
ion would be outside manufacturer's remit and the insurer's plus too many
risks-the fuel tank is directly above the battery housings. I would like
something with at least 9 amp hours, whether gel cell or mh.

[[email protected]]

On Wednesday, October 2, 2013 12:46:32 PM UTC-5, John Marshall wrote:
> I need advice about the best choice of batteries for an asg 29e. lithium
>
> ion would be outside manufacturer's remit and the insurer's plus too many
>
> risks-the fuel tank is directly above the battery housings. I would like
>
> something with at least 9 amp hours, whether gel cell or mh.

Used NiMh in my LS8 for about 5 years and can add some advice on those. Found the life span not much different from Pb gel-cells at about 2-3 years in spite of using specific chargers. Advantage is weight, around half of the lead cells. Disadvantage in self-discharge rates, these are high and you have to top off the battery if you want full capacity. Voltage drop is steep, just like for a Pb-cell. Flying with LiFe-PO4 now and have had no problems.
Herb

[Roy Pentecost]

My ASG29E uses two lead acid gel cell batteries each with 9AH capacity,
these sit on the parcel shelf beneath the fuel tank. These are supplemented
by the solar panels that deliver about 1A in bright sunshine.
My panel includes LX8000 with flarm, V3 vario, Filser ATR500 radio, LX nano
logger and Glider Guider PNA (similar to an Oudie), also occasional use of
a Dynon Artificial Horizon.
I guess if you don't have the solar panels or if you use a transponder then
capacity will start to become an issue unless you go to Li-ion.

Regards,
Roy

[[email protected][_2_]]

This season, I changed to two LiFePO4. They served me well. The biggest enemy to endurance continues to be radio transmissions (hand signals only go so far). While flying, I monitored their voltage and was very pleased; my longest flight was just under six hours.

My electrical devices are these: radio, transponder, 302, 303, FLARM, and Oudie.

Raul Boerner
LS6-b
DM

[[email protected]]

On Wednesday, October 2, 2013 2:52:05 PM UTC-4, wrote:
> This season, I changed to two LiFePO4. They served me well.

> My electrical devices are these: radio, transponder, 302, 303, FLARM, and Oudie.
>
>
>
> Raul Boerner
>
> LS6-b
>
> DM



Raul,
What capacity LiFePO4 are you using?

[JJ Sinclair[_2_]]

On Wednesday, October 2, 2013 10:46:32 AM UTC-7, John Marshall wrote:
> I need advice about the best choice of batteries for an asg 29e. lithium
>
> ion would be outside manufacturer's remit and the insurer's plus too many
>
> risks-the fuel tank is directly above the battery housings. I would like
>
> something with at least 9 amp hours, whether gel cell or mh.

I flew a 12 a/h LiFe PO4 this year and can't say enough about it performance. I haven't seen the voltage drop much below 12.9 V, even on a 4 hour flight with everything on, Radio, transponder, Power flarm, Model-20 & Garmin GPS's, SN-10, B-500. AND it weighs half its lead acid 12 a/h brother which would give up in less than 3 hours.
JJ

[glidergreg]

On Wednesday, October 2, 2013 12:46:32 PM UTC-5, John Marshall wrote:
> I need advice about the best choice of batteries for an asg 29e. lithium
>
> ion would be outside manufacturer's remit and the insurer's plus too many
>
> risks-the fuel tank is directly above the battery housings. I would like
>
> something with at least 9 amp hours, whether gel cell or mh.

Same advise as JJ and Herb, Buy this and you won't be sorry. Here is a link to where I got mine.

http://www.bioennopower.com/pages/12v-9ah-lifepo4-battery

[[email protected][_2_]]

Each of my LiFePO4 batteries is 9AH.

[[email protected][_2_]]

Each of my LiFePO4 batteries is 9AH.

[6PK]

On Wednesday, October 2, 2013 2:03:06 PM UTC-7, JJ Sinclair wrote:
> On Wednesday, October 2, 2013 10:46:32 AM UTC-7, John Marshall wrote:
>
> > I need advice about the best choice of batteries for an asg 29e. lithium
>
> >
>
> > ion would be outside manufacturer's remit and the insurer's plus too many
>
> >
>
> > risks-the fuel tank is directly above the battery housings. I would like
>
> >
>
> > something with at least 9 amp hours, whether gel cell or mh.
>
>
>
> I flew a 12 a/h LiFe PO4 this year and can't say enough about it performance. I haven't seen the voltage drop much below 12.9 V, even on a 4 hour flight with everything on, Radio, transponder, Power flarm, Model-20 & Garmin GPS's, SN-10, B-500. AND it weighs half its lead acid 12 a/h brother which would give up in less than 3 hours.
>
> JJ

I been thinking about changing to the LiFe Po4 well but must admit I am somewhat apprehensive.
It sounds like the 12ah version should be better (space allowing) than the 9ah for obvious reasons and I am not sure about the charging procedures either.
The chargers these batteries come with are they sufficient enough?
Can one leave them on overnight, etc, do they overcharge or like the gel cell smart chargers; switch to trickle charge?
If I sound ignorant about this, it is because I am .
Any advise would be appreciated.
6PK

[Dave Springford]

Don't confuse the Li-Ion batteries with the LiFePo4 batteries that are mentioned above. While the Li-Ion batteries have the instability problems associated with thermal runaway during rapid discharge, the Lithium-Iron-Phosphate (LiFePo4) chemistry is stable and do not have these problems.

There are many knock-off Chinese battery packs on the market that are called LiFePo, but be careful what you buy. I am a re-seller for K2 Energy batteries, and these are made in the USA, true LiFePo4 chemistry. I have spent hours on the phone with Mark Stoker at K2 comparing their batteries to some of the cheaper competition and some of the competitors numbers don't add up. The LiFePo4 chemistry is patented and K2 pays patent fees to the patent holder to use it, while many of the others don't. Visit the K2 website for more information at: http://www.k2battery.com/battery-packs-12v.html

Some of the advantages of the LiFePo4 chemistry over the SLA's (sealed Lead Acid) is that it holds peak voltage for much longer during discharge. The SLA's discharge curve is a continually declining slope that quickly reaches the 10 V level where things start to shut-off, while the LiFePo4 discharge curve is almost a straight line from the initial charge of 13 V. See the discharge curve here:
http://www.foxonecorp.com/images/stories/k2%20discharge.png

Advantages of the LiFePo4 batteries

provide much longer battery use during flight.

can be used for at least 2000 discharge-recharge cycles, compared to 300 for SLA's

hold their charge during the off-season loosing only 1% per month (unlike the SLA batteries that loose 25-30% per month)

don't have the special charge/discharge requirements of the early Li-ion types and can be charged with most normal SLA chargers as long as they can provide a 14.6 V peak charge voltage

The K2 batteries have the highest capacity available at ANY discharge rate available on the market.


Contact me if you would like more info

Dave Springford
www.foxonecorp.com

[Dave Springford]

In response to 6PK about the charging:

Yes, the chargers are smart trickle chargers that can be left on the LiFePo4 packs indefinitely.

[6PK]

On Wednesday, October 2, 2013 4:15:29 PM UTC-7, Dave Springford wrote:
> Don't confuse the Li-Ion batteries with the LiFePo4 batteries that are mentioned above. While the Li-Ion batteries have the instability problems associated with thermal runaway during rapid discharge, the Lithium-Iron-Phosphate (LiFePo4) chemistry is stable and do not have these problems.
>
>
>
> There are many knock-off Chinese battery packs on the market that are called LiFePo, but be careful what you buy. I am a re-seller for K2 Energy batteries, and these are made in the USA, true LiFePo4 chemistry. I have spent hours on the phone with Mark Stoker at K2 comparing their batteries to some of the cheaper competition and some of the competitors numbers don't add up. The LiFePo4 chemistry is patented and K2 pays patent fees to the patent holder to use it, while many of the others don't. Visit the K2 website for more information at: http://www.k2battery.com/battery-packs-12v.html
>
>
>
> Some of the advantages of the LiFePo4 chemistry over the SLA's (sealed Lead Acid) is that it holds peak voltage for much longer during discharge. The SLA's discharge curve is a continually declining slope that quickly reaches the 10 V level where things start to shut-off, while the LiFePo4 discharge curve is almost a straight line from the initial charge of 13 V. See the discharge curve here:
>
> http://www.foxonecorp.com/images/stories/k2%20discharge.png
>
>
>
> Advantages of the LiFePo4 batteries
>
>
>
> provide much longer battery use during flight.
>
>
>
> can be used for at least 2000 discharge-recharge cycles, compared to 300 for SLA's
>
>
>
> hold their charge during the off-season loosing only 1% per month (unlike the SLA batteries that loose 25-30% per month)
>
>
>
> don't have the special charge/discharge requirements of the early Li-ion types and can be charged with most normal SLA chargers as long as they can provide a 14.6 V peak charge voltage
>
>
>
> The K2 batteries have the highest capacity available at ANY discharge rate available on the market.
>
>
>
>
>
> Contact me if you would like more info
>
>
>
> Dave Springford
>
> www.foxonecorp.com

Dave.I have been using both 14 v and 12 v batteries; 14v10ah (Sonnechein) and 12v12ah (Power Sonic) .
The chargers are a 14v trickle charger and 12v "Battery Minder" both work fine
Am I to understand that both these chargers (even the 14v??)would work?
Thanks in advance.
6PK

[Dave Springford]

The 14 V charger would probably work best as the LiFePo4 batteries need a 14.6 V max charge rate. I tried some 12 V chargers and they max out at 13.75 V and this will not give the full charge the LiFePo battery needs. The K2 battery comes with a Battery Management System that helps regulate the charge and discharge rates. This combined with the trickle on your charger will prevent over-charging.

Check the specs on your 14 V charger, these should be printed somewhere on the back of the charger, (ie Input 110-120 V AC 60 Hz, Output 13.75 V DC, Current 750 mA) If you can't find it on the charger, connect the charger to a battery and measure the voltage across the terminals with a Voltmeter.

[Eric Greenwell[_4_]]

Dave Springford wrote, On 10/2/2013 4:15 PM:
> LiFePo4 batteries hold their charge during the off-season loosing
> only 1% per month (unlike the SLA batteries that loose 25-30% per
> month)

SLA's lose around 3% per month at 68 deg F, and less at the temperatures
typical in the winter off-season. Mine don't lose much more than that,
even in the higher summer temperatures. Any SLA that loses, say, over
10% during the winter, is defective and should be discarded.

Perhaps you were thinking of Ni-Cd or Nimh batteries?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Papa3[_2_]]

Further to Dave's comments, I've done some simple discharge testing on my K2 12V/10AH LiFePo4, and it's pretty impressive. At a discharge rate of over 1C, I'm seeing the nearly the full rated capacity (1.2A bulb simulating the load). It never drops below 11V until it starts to fall off rapidly and shuts itself off. I'm seeing 7 hours at that rate (the capacity is theoretically derived at a discharge rate of 1 Amp, so it "should" be a little less than 10AH at the higher discharge rate as I understand it. I use the same smart charger that I used to use for 12V SLA batteries, and it seems to be working just fine. I would love to see an even higher capacity version, even with the larger foot print. The energy density is such that it would still be significantly lighter than an equivalent SLA battery.

P3



On Wednesday, October 2, 2013 7:15:29 PM UTC-4, Dave Springford wrote:
> Don't confuse the Li-Ion batteries with the LiFePo4 batteries that are mentioned above. While the Li-Ion batteries have the instability problems associated with thermal runaway during rapid discharge, the Lithium-Iron-Phosphate (LiFePo4) chemistry is stable and do not have these problems.
>
>
>
> There are many knock-off Chinese battery packs on the market that are called LiFePo, but be careful what you buy. I am a re-seller for K2 Energy batteries, and these are made in the USA, true LiFePo4 chemistry. I have spent hours on the phone with Mark Stoker at K2 comparing their batteries to some of the cheaper competition and some of the competitors numbers don't add up. The LiFePo4 chemistry is patented and K2 pays patent fees to the patent holder to use it, while many of the others don't. Visit the K2 website for more information at: http://www.k2battery.com/battery-packs-12v.html
>
>
>
> Some of the advantages of the LiFePo4 chemistry over the SLA's (sealed Lead Acid) is that it holds peak voltage for much longer during discharge. The SLA's discharge curve is a continually declining slope that quickly reaches the 10 V level where things start to shut-off, while the LiFePo4 discharge curve is almost a straight line from the initial charge of 13 V. See the discharge curve here:
>
> http://www.foxonecorp.com/images/stories/k2%20discharge.png
>
>
>
> Advantages of the LiFePo4 batteries
>
>
>
> provide much longer battery use during flight.
>
>
>
> can be used for at least 2000 discharge-recharge cycles, compared to 300 for SLA's
>
>
>
> hold their charge during the off-season loosing only 1% per month (unlike the SLA batteries that loose 25-30% per month)
>
>
>
> don't have the special charge/discharge requirements of the early Li-ion types and can be charged with most normal SLA chargers as long as they can provide a 14.6 V peak charge voltage
>
>
>
> The K2 batteries have the highest capacity available at ANY discharge rate available on the market.
>
>
>
>
>
> Contact me if you would like more info
>
>
>
> Dave Springford
>
> www.foxonecorp.com

[Dave Springford]

I guess it depends on how one defines capacity. If you take it as voltage drop from 12V then it is probably the 3% value that you use. If you take it as the battery's ability to do work and the SLA stops doing useful work at 10 V, then you have a 2V range from which the percentage is calculated resulting in the larger drop I quote.

Of course, the thing about statistics is that they will tell you whatever you want if you torture them long enough.

[6PK]

On Wednesday, October 2, 2013 5:09:18 PM UTC-7, Dave Springford wrote:
> The 14 V charger would probably work best as the LiFePo4 batteries need a 14.6 V max charge rate. I tried some 12 V chargers and they max out at 13..75 V and this will not give the full charge the LiFePo battery needs. The K2 battery comes with a Battery Management System that helps regulate the charge and discharge rates. This combined with the trickle on your charger will prevent over-charging.
>
>
>
> Check the specs on your 14 V charger, these should be printed somewhere on the back of the charger, (ie Input 110-120 V AC 60 Hz, Output 13.75 V DC, Current 750 mA) If you can't find it on the charger, connect the charger to a battery and measure the voltage across the terminals with a Voltmeter.

Great information on RAS as usual.
Dave my 14v charger has no specs other than it is 14v
I did what you suggested, hooked it up to a battery and tested the terminal on the battery; it read 15.68 v.
Is that too high?
Regards. 6PK

[Dave Springford]

I will confirm with K2, but it is likely too high.

[Eric Greenwell[_4_]]

6PK wrote, On 10/2/2013 6:48 PM:
> On Wednesday, October 2, 2013 5:09:18 PM UTC-7, Dave Springford
> wrote:
>> The 14 V charger would probably work best as the LiFePo4 batteries
>> need a 14.6 V max charge rate. I tried some 12 V chargers and they
>> max out at 13.75 V and this will not give the full charge the
>> LiFePo battery needs. The K2 battery comes with a Battery
>> Management System that helps regulate the charge and discharge
>> rates. This combined with the trickle on your charger will prevent
>> over-charging.
>>
>>
>>
>> Check the specs on your 14 V charger, these should be printed
>> somewhere on the back of the charger, (ie Input 110-120 V AC 60 Hz,
>> Output 13.75 V DC, Current 750 mA) If you can't find it on the
>> charger, connect the charger to a battery and measure the voltage
>> across the terminals with a Voltmeter.
>
> Great information on RAS as usual. Dave my 14v charger has no specs
> other than it is 14v I did what you suggested, hooked it up to a
> battery and tested the terminal on the battery; it read 15.68 v. Is
> that too high? Regards. 6PK

DON'T use 12 volt single stage chargers (also known as "taper" or
"trickle" chargers) on these batteries, and ESPECIALLY DON'T use 14 volt
chargers of any type. Trickle chargers aren't even good choices for SLA
batteries. Buy the K2 charger (it's a $150 battery - it's worth charging
it properly, in addition to the safety aspects), or use a charger they
have specifically approved (likely a 3 stage charger for 12 volt batteries).

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Eric Greenwell[_4_]]

Dave Springford wrote, On 10/2/2013 5:57 PM:
> I guess it depends on how one defines capacity. If you take it as
> voltage drop from 12V then it is probably the 3% value that you use.
> If you take it as the battery's ability to do work and the SLA stops
> doing useful work at 10 V, then you have a 2V range from which the
> percentage is calculated resulting in the larger drop I quote.
>
> Of course, the thing about statistics is that they will tell you
> whatever you want if you torture them long enough.

Capacity is defined as amp hours (sometimes energy is used). It is
definitely not defined as voltage or voltage lost, though measuring
"standing" voltage is one way to estimate the state of charge. Fully
charge an SLA battery, let it sit for a month at 68 deg F, measure the
amp hours, and they will be about 3% less than if you had measured them
right after charging. That means an 8 amp hour battery loses about 0.24
amp hours a month. The voltage will also fall during the month,
approximately 3% of that two volt working range, or about 0.05 volts.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[JS]

The original post was evidently about old batteries that just need replacing with anything new. Replace with the less expensive SLA if you don't intend to fly long days or multiple days without charging, and don't mind replacing again soon. There are no "made in USA" SLA batteries. Hawker Cyclon (used to be Gates X Cell) are the only holdout.
All the "SLA replacement" LiFePO4 batteries have overcharge and over discharge protection. You can use any good multi-stage charger for 12V batteries. Personally prefer the Xenotronics.
Here's a controller (from a much earlier thread) you can use in the trailer to charge two onboard batteries. Works for LiFePO4, but misses the top few millivolts. You can still do a 750k or so on one 10AH LiFePO4 charged with them if you have a full modern panel (VGA display, transponder, com, flarm, etc)
Jim

http://www.futurlec.com/Dual_Charge_Controller.shtml

[Dan Marotta]

<snip>If you can't find it on the charger, connect the charger to a battery
and measure the voltage across the terminals with a Voltmeter.

That won't work too well due to the internal resistance unless the battery
is already practically fully charged. I've looked at some of these
batteries on Amazon and some have a bundled charger which is probably the
best of both worlds.

My 14v charger brings my 14v battery up to about 15.6v. That might be too
much to safely charge the LiFePO4 batteries. My 12v charger may be too
little...

[Dan Marotta]

Call me an energy whore, but I'm looking at this one:
http://www.amazon.com/Bioenno-Power-Lithium-Phosphate-LiFePO4/dp/B0083BRCRW/ref=sr_1_15?ie=UTF8&qid=1380809142&sr=8-15&keywords=lifepo4+battery


"Papa3" > wrote in message
...
Further to Dave's comments, I've done some simple discharge testing on my K2
12V/10AH LiFePo4, and it's pretty impressive. At a discharge rate of over
1C, I'm seeing the nearly the full rated capacity (1.2A bulb simulating the
load). It never drops below 11V until it starts to fall off rapidly and
shuts itself off. I'm seeing 7 hours at that rate (the capacity is
theoretically derived at a discharge rate of 1 Amp, so it "should" be a
little less than 10AH at the higher discharge rate as I understand it. I
use the same smart charger that I used to use for 12V SLA batteries, and it
seems to be working just fine. I would love to see an even higher capacity
version, even with the larger foot print. The energy density is such that
it would still be significantly lighter than an equivalent SLA battery.

P3



On Wednesday, October 2, 2013 7:15:29 PM UTC-4, Dave Springford wrote:
> Don't confuse the Li-Ion batteries with the LiFePo4 batteries that are
> mentioned above. While the Li-Ion batteries have the instability problems
> associated with thermal runaway during rapid discharge, the
> Lithium-Iron-Phosphate (LiFePo4) chemistry is stable and do not have these
> problems.
>
>
>
> There are many knock-off Chinese battery packs on the market that are
> called LiFePo, but be careful what you buy. I am a re-seller for K2
> Energy batteries, and these are made in the USA, true LiFePo4 chemistry.
> I have spent hours on the phone with Mark Stoker at K2 comparing their
> batteries to some of the cheaper competition and some of the competitors
> numbers don't add up. The LiFePo4 chemistry is patented and K2 pays
> patent fees to the patent holder to use it, while many of the others
> don't. Visit the K2 website for more information at:
> http://www.k2battery.com/battery-packs-12v.html
>
>
>
> Some of the advantages of the LiFePo4 chemistry over the SLA's (sealed
> Lead Acid) is that it holds peak voltage for much longer during discharge.
> The SLA's discharge curve is a continually declining slope that quickly
> reaches the 10 V level where things start to shut-off, while the LiFePo4
> discharge curve is almost a straight line from the initial charge of 13 V.
> See the discharge curve here:
>
> http://www.foxonecorp.com/images/stories/k2%20discharge.png
>
>
>
> Advantages of the LiFePo4 batteries
>
>
>
> provide much longer battery use during flight.
>
>
>
> can be used for at least 2000 discharge-recharge cycles, compared to
> 300 for SLA's
>
>
>
> hold their charge during the off-season loosing only 1% per month
> (unlike the SLA batteries that loose 25-30% per month)
>
>
>
> don't have the special charge/discharge requirements of the early
> Li-ion types and can be charged with most normal SLA chargers as long as
> they can provide a 14.6 V peak charge voltage
>
>
>
> The K2 batteries have the highest capacity available at ANY discharge
> rate available on the market.
>
>
>
>
>
> Contact me if you would like more info
>
>
>
> Dave Springford
>
> www.foxonecorp.com

[Evan Ludeman[_4_]]

On Thursday, October 3, 2013 10:06:36 AM UTC-4, Dan Marotta wrote:
> Call me an energy whore, but I'm looking at this one:
>
> http://www.amazon.com/Bioenno-Power-Lithium-Phosphate-LiFePO4/dp/B0083BRCRW/ref=sr_1_15?ie=UTF8&qid=1380809142&sr=8-15&keywords=lifepo4+battery
>


P-l-e-a-s-e use batteries in rugged (e.g. ABS) cases, not poly shrink wrap.

I've had good luck so far with the Bioenno 12 AH LFP battery + charger.

-Evan Ludeman / T8

[Clay[_4_]]

"P-l-e-a-s-e use batteries in rugged (e.g. ABS) cases, not poly shrink wrap."

How about bamboo!?
http://www.electric-bike-kit.com/lithium-12v-lifepo4sla-replacement.aspx

[Soartech]

GO SOLAR ! I have not charged my batteries since spring! Why spend money on a new Lithium with specialized charger when we fly only on sunny days? Paper thin solar panels are only around $100 each and the regulator can be bought on Amazon for $11. Your battery is charging the instant you roll out of the trailer. Here is just one of many places to buy the panels:
https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_228208_-1

[Dave Springford]

On Wednesday, October 2, 2013 10:05:09 PM UTC-4, Dave Springford wrote:
> I will confirm with K2, but it is likely too high.

K2 tells me that as long as the battery has the BMS, your 14 V charger with 15.7 V output will be OK to charge their LiFePo4 battery.

[Dan Marotta]

The battery I linked to is by the same manufacturer you're espousing. I've
read the technical details and can't find anything about the case, much less
"poly shrink wrap". Where did you come up with that description?

If it is, indeed, a flimsy wrapper, I could always make a fiberglass box to
house it and bond it into the fuselage very near the CG.

"Evan Ludeman" > wrote in message
...
> On Thursday, October 3, 2013 10:06:36 AM UTC-4, Dan Marotta wrote:
>> Call me an energy whore, but I'm looking at this one:
>>
>> http://www.amazon.com/Bioenno-Power-Lithium-Phosphate-LiFePO4/dp/B0083BRCRW/ref=sr_1_15?ie=UTF8&qid=1380809142&sr=8-15&keywords=lifepo4+battery
>>
>
>
> P-l-e-a-s-e use batteries in rugged (e.g. ABS) cases, not poly shrink
> wrap.
>
> I've had good luck so far with the Bioenno 12 AH LFP battery + charger.
>
> -Evan Ludeman / T8

[Dan Marotta]

Please describe your layout with a parts list.

Just a quick look at the products in your link would lead me to believe I'd
need 7 or 8 (or more) of those, at about $90 EACH plus a controller. The
LiFEPO4 battery at $200 can be charged 2000 times at 100% charge. At my age
I don't think I have another 2,000 flights left!

Or... Is it your suggestion simply to supplement your SLA batteries with
the solar cells rather than power your ship with them?

"Soartech" > wrote in message
...
GO SOLAR ! I have not charged my batteries since spring! Why spend money on
a new Lithium with specialized charger when we fly only on sunny days? Paper
thin solar panels are only around $100 each and the regulator can be bought
on Amazon for $11. Your battery is charging the instant you roll out of the
trailer. Here is just one of many places to buy the panels:
https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_228208_-1

[Evan Ludeman[_4_]]

On Thursday, October 3, 2013 6:02:43 PM UTC-4, Dan Marotta wrote:
> The battery I linked to is by the same manufacturer you're espousing. I've
>
> read the technical details and can't find anything about the case, much less
>
> "poly shrink wrap". Where did you come up with that description?
>


About halfway down the page where it says: "Packaging: PVC shrinkwrap"

That much stored energy deserves robust packaging.

-Evan

[6PK]

On Thursday, October 3, 2013 2:48:38 PM UTC-7, Dave Springford wrote:
> On Wednesday, October 2, 2013 10:05:09 PM UTC-4, Dave Springford wrote:
>
> > I will confirm with K2, but it is likely too high.
>
>
>
> K2 tells me that as long as the battery has the BMS, your 14 V charger with 15.7 V output will be OK to charge their LiFePo4 battery.

Thanks Dave
I am ordering one of these units.
Much appreciate all the help. 6PK

[Dave Springford]

I think if you look at this page:
http://www.bioennopower.com/pages/12v-10ah-lifepo4-battery

You will see that the pack in the picture is covered in shrink wrap, not in a solid ABS-case. Take a look at the bulge on the right side of the pack and the fold at the top right corner.

[Evan Ludeman[_4_]]

On Thursday, October 3, 2013 8:00:41 PM UTC-4, Dave Springford wrote:
> I think if you look at this page:
>
> http://www.bioennopower.com/pages/12v-10ah-lifepo4-battery
>
>
>
> You will see that the pack in the picture is covered in shrink wrap, not in a solid ABS-case. Take a look at the bulge on the right side of the pack and the fold at the top right corner.

This is the one I use: http://www.bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-12ah-lifepo4-battery

-Evan

[Eric Greenwell[_4_]]

Soartech wrote, On 10/3/2013 10:04 AM:
> GO SOLAR ! I have not charged my batteries since spring! Why spend
> money on a new Lithium with specialized charger when we fly only on
> sunny days? Paper thin solar panels are only around $100 each and the
> regulator can be bought on Amazon for $11. Your battery is charging
> the instant you roll out of the trailer. Here is just one of many
> places to buy the panels:
> https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_228208_-1

I've been interested in these panels, but they are not very efficent.
The one you reference is only 200 ma, but nearly a foot square. I'd need
8 of them to keep up with my instruments, and that would be with them
aimed directly into the sun. Circling, clouds, etc, and I would probably
average more like 500 ma during the flight instead of the peak 1600 ma.

How many of them do you use? Where do you mount them? What is the
current draw of your instruments?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[[email protected]]

The battery placement in the ASG29E in my opinion doesn't allow anything else than the standard 151x65x94mm size. Therefore shrinkwrapped batterys won't work, and some of the mentioned >10Ah ones are too big.

[Jim White[_3_]]

I have fitted a Strobl panel to my ASW27 and have reverted to 9ah SLA. As
long as the sun shines the batteries stay in the glider all season. My
chargers now only get used in winter.

www.strobl-solar.de


At 22:10 03 October 2013, Dan Marotta wrote:
>Please describe your layout with a parts list.
>
>Just a quick look at the products in your link would lead me to believe
I'd
>
>need 7 or 8 (or more) of those, at about $90 EACH plus a controller. The

>LiFEPO4 battery at $200 can be charged 2000 times at 100% charge. At my
>age
>I don't think I have another 2,000 flights left!
>
>Or... Is it your suggestion simply to supplement your SLA batteries with

>the solar cells rather than power your ship with them?
>
>"Soartech" wrote in message
...
>GO SOLAR ! I have not charged my batteries since spring! Why spend money
on
>
>a new Lithium with specialized charger when we fly only on sunny days?
>Paper
>thin solar panels are only around $100 each and the regulator can be
bought
>
>on Amazon for $11. Your battery is charging the instant you roll out of
the
>
>trailer. Here is just one of many places to buy the panels:
>https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_228208_-1
>
>
>

[Dan Marotta]

I missed that, Evan - THANKS!

Depending upon the size, I could still fab a box in the fuselage or ask
Fidel at Applebay Aircraft to do it for me.

I took a look at the Strobl setup and it looks great, but the price of
$2078.40 kinda put me off. Is shipping from Europe extra? Did I make a
mistake? I hit the "Buy" button and went to the cart to have a look and
that's the price I got.

"Evan Ludeman" > wrote in message
...
> On Thursday, October 3, 2013 6:02:43 PM UTC-4, Dan Marotta wrote:
>> The battery I linked to is by the same manufacturer you're espousing.
>> I've
>>
>> read the technical details and can't find anything about the case, much
>> less
>>
>> "poly shrink wrap". Where did you come up with that description?
>>
>
>
> About halfway down the page where it says: "Packaging: PVC shrinkwrap"
>
> That much stored energy deserves robust packaging.
>
> -Evan
>

[Soartech]

Regarding the solar cells.
Dan and Eric, I am suggesting to use your current lead acid battery(s) and charge them with solar. The idea is that they charge during the time the glider is on the ground before and after flight and supplement while in flight. During flight the 200 mA.of one cell may not cover all of your current draw, most likely. It might for me as I just have a vario, radio and Streak connected. My experience is that the battery charges enough to keep it going all summer. Try two cells to start with and I think you will be surprised how well it works. It's way better than removing the battery after every flight, taking it home and charging it which is what my friend does.
I also have a 15 Watt panel on my trailer that runs a 4 inch 12V computer fan I installed behind the vent grill but I can switch it over to charge the battery if I need to via a wire pair. So far I have not needed to use it for charging. Trailer stays cool all summer.

[Soartech]

> I took a look at the Strobl setup and it looks great, but the price of
>
> $2078.40 kinda put me off.

That price is way out of line with today's solar equipment. Someone is making a lot of profit at that level. Search around. Look at Amazon, solarblvd.com and eBay. This is not rocket science.

[waremark]

Can someone recommend the best LifePo battery which fits in a completely standard bracket? (In my case for an Arcus M - I have 4 Strobl panels which are supposed to generate 2.4 Ah, but I have the max amount of electronics fitted - I have not run out of power yet with 2 ordinary 7Ah gel cells, but think I might run out if a flight lasted for more than 8 hours).

Thanks for any advice, Mark Burton, 4M, London Gliding Club, UK

[Eric Greenwell[_4_]]

Soartech wrote, On 10/4/2013 10:29 AM:
>
>> I took a look at the Strobl setup and it looks great, but the price
>> of
>>
>> $2078.40 kinda put me off.
>
> That price is way out of line with today's solar equipment. Someone
> is making a lot of profit at that level. Search around. Look at
> Amazon, solarblvd.com and eBay. This is not rocket science.

I'm pretty much required to mount any solar panels on my engine doors,
which limits the area available. Strobl panels are very efficient, so
you get a lot of amps in a small size, and they flexible. That's what
you are paying for. If you know of panels comparable to the Strobls in
output for a lot less, I'd really like to know about them! I really,
really would! I have looked for such panels in the past, with no success.

Two Strobl modules for my glider, with switches, cables, adhesive,
connectors, etc, produce a nominal 860 ma., and use 1.5 sqft. The "kit"
costs 1040 Eur ($1400 US$). The panels you suggested would occupy 4.0
sqft, way too big for the engine doors, it wouldn't have all the stuff
needed for installation in a specific glider, and it wouldn't be
approved by the glider manufacturer. It may not be rocket science, but
there are good reasons that the Strobls are what you see on most gliders.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Eric Greenwell[_4_]]

Soartech wrote, On 10/4/2013 10:17 AM:
> Regarding the solar cells. Dan and Eric, I am suggesting to use your
> current lead acid battery(s) and charge them with solar. The idea is
> that they charge during the time the glider is on the ground before
> and after flight and supplement while in flight. During flight the
> 200 mA.of one cell may not cover all of your current draw, most
> likely. It might for me as I just have a vario, radio and Streak
> connected. My experience is that the battery charges enough to keep
> it going all summer. Try two cells to start with and I think you will
> be surprised how well it works. It's way better than removing the
> battery after every flight, taking it home and charging it which is
> what my friend does. I also have a 15 Watt panel on my trailer that
> runs a 4 inch 12V computer fan I installed behind the vent grill but
> I can switch it over to charge the battery if I need to via a wire
> pair. So far I have not needed to use it for charging. Trailer stays
> cool all summer.

For your low current drain situation, 200 ma is worthwhile;
unfortunately, with a ClearNav, radio, 302, Mode C transponder,
PowerFlarm, my panel draws 2 amps until the transponder encoder is warm,
then it still draws 1.6 amps. A six hour flight uses over 9 AH.

If I had two panels with a total of 400 ma, they'd average less than 200
ma during a flight (much less if there are plenty of clouds), or only
1.2 AH added during the flight. That's insignificant, compared to the 9
AH usage.

Charging while it's tied down is problematic, too: The sun angle will
not be optimum (especially after flying), and it might be cloudy in the
morning. I need a 40 watt panel, optimally placed on the ground, to
ensure the glider is charged fully by launch time the next day. Usually,
instead of a solar panel, I use a DC/DC charger and an 18 AH battery to
do the charging overnight when I'm tied down.

It's the high drains a modern panel can consume that get people looking
at high capacity batteries and Strobl panels. Many pilots could do well
with your suggestions, however.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Dan Marotta]

Thanks for the info.

Like Eric, I have high drain with the Mode S transponder (Trig TT22),
Microair 760 radio, CAI-302, Zaon MRX, and Dell Streak, all drawing on my
batteries. I estimate about 1.6-2.0 Amp hours drain.

Fortunately, for me, my glider is kept assembled in a hangar with chargers
connected full time. On the road, I have an inverter to charge up the
batteries if needed. Still, after 4 hours or so of flight, my batteries are
getting low. I need to replace them and I'm looking for something better
than SLA.

"Soartech" > wrote in message
...
Regarding the solar cells.
Dan and Eric, I am suggesting to use your current lead acid battery(s) and
charge them with solar. The idea is that they charge during the time the
glider is on the ground before and after flight and supplement while in
flight. During flight the 200 mA.of one cell may not cover all of your
current draw, most likely. It might for me as I just have a vario, radio and
Streak connected. My experience is that the battery charges enough to keep
it going all summer. Try two cells to start with and I think you will be
surprised how well it works. It's way better than removing the battery after
every flight, taking it home and charging it which is what my friend does.
I also have a 15 Watt panel on my trailer that runs a 4 inch 12V computer
fan I installed behind the vent grill but I can switch it over to charge the
battery if I need to via a wire pair. So far I have not needed to use it for
charging. Trailer stays cool all summer.

[Dave Springford]

Mark,

In North America, I would recommend the K2, but shipping to Europe is going to be an issue for you as may be duties. For me to import the Batteries to Canada from the US, it costs almost 50% more because of this. So you should look for a European manufacturer.

Or if you go to the US or have a friend the goes to the US take a look at the K2, or the Bioenno as suggested above and carry them home.

[GC[_2_]]

On 4/10/2013 10:00, Dave Springford wrote:
> I think if you look at this page:
> http://www.bioennopower.com/pages/12v-10ah-lifepo4-battery
>
> You will see that the pack in the picture is covered in shrink wrap,
> not in a solid ABS-case. Take a look at the bulge on the right side
> of the pack and the fold at the top right corner.


Yes. If you click "1. 12V Series" on the right hand menu you can see
that ABS cases are available as alternatives. The shrink wrap appears
to cover a PVC case.

GC

[Peter Scholz[_3_]]

Am 04.10.2013 19:36, waremark wrote:
> Can someone recommend the best LifePo battery which fits in a completely standard bracket? (In my case for an Arcus M - I have 4 Strobl panels which are supposed to generate 2.4 Ah, but I have the max amount of electronics fitted - I have not run out of power yet with 2 ordinary 7Ah gel cells, but think I might run out if a flight lasted for more than 8 hours).
>
> Thanks for any advice, Mark Burton, 4M, London Gliding Club, UK
>
Mark,

I'd recommend this 10Ah LiFePO4 product which sells for 149.00 EUR:

http://shop.segelflugbedarf24.de/product_info.php?info=p922_Airbatt-LiFePO4-12V-10Ah.html

They also ship to UK for reasonable fares. The dimensions are the usual
151 x 65 x 94 mm and the unit contains a BMS protection and balancing
circuit. It can be charged with the usual Lead-Acid battery chargers
with no problem.

--
Peter Scholz
ASW24 JE

[Dan Marotta]

This looks very interesting to me:
http://www.bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-6ah-lifepo4-battery

On the surface it appears that I may be able to wire two of them in parallel
(or series-parallel if individual cells) and enclose them in the battery
case that fits in the tail of my LAK. I'll measure it today and see if
there's a chance.



"Peter Scholz" > wrote in message
...
> Am 04.10.2013 19:36, waremark wrote:
>> Can someone recommend the best LifePo battery which fits in a completely
>> standard bracket? (In my case for an Arcus M - I have 4 Strobl panels
>> which are supposed to generate 2.4 Ah, but I have the max amount of
>> electronics fitted - I have not run out of power yet with 2 ordinary 7Ah
>> gel cells, but think I might run out if a flight lasted for more than 8
>> hours).
>>
>> Thanks for any advice, Mark Burton, 4M, London Gliding Club, UK
>>
> Mark,
>
> I'd recommend this 10Ah LiFePO4 product which sells for 149.00 EUR:
>
> http://shop.segelflugbedarf24.de/product_info.php?info=p922_Airbatt-LiFePO4-12V-10Ah.html
>
> They also ship to UK for reasonable fares. The dimensions are the usual
> 151 x 65 x 94 mm and the unit contains a BMS protection and balancing
> circuit. It can be charged with the usual Lead-Acid battery chargers with
> no problem.
>
> --
> Peter Scholz
> ASW24 JE

[Chris Nicholas[_2_]]

Dan, not wishing to teach granny to suck eggs, but if you go for
Lipo in the tail (or anywhere), make sure you have a proper
battery management system in addition to a charger – apparently
the significant number of fires in Lipos in model aircraft were due to
inadequate or absent BMS. Otherss here will have more first-hand
knowledge.

(The Lak FES comes with a proper BMS for this very reason.)


Chris N

[Eric Greenwell[_4_]]

Dan Marotta wrote, On 10/5/2013 8:22 AM:
> This looks very interesting to me:
> http://www.bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-6ah-lifepo4-battery
>
>
> On the surface it appears that I may be able to wire two of them in
> parallel (or series-parallel if individual cells) and enclose them in
> the battery case that fits in the tail of my LAK. I'll measure it today
> and see if there's a chance.

Be certain to read the user manual for this battery, which specifically
states series or parallel operation is not recommended! The manual also
states

"Only use 14.6V, LiFePO4 compatible chargers to charge the battery. The
charging current should be between 2A to 5A. If you need a charger,
please contact us"

Don't rely on claims for other Li batteries, like "any lead acid charger
can be used", but only go by the requirements of the manufacturer of the
battery you have.

Lithium based batteries must be taken more seriously than SLA
batteries, which are nearly identical from one manufacturer to another.
Lithium batteries, even LiFePO4, can vary substantially in their
characteristics, particularly with the type of BMS (battery management
system) installed in it, and may not even have one. Even the proper
storage varies considerably between Li and lead batteries.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Eric Greenwell[_4_]]

Dan Marotta wrote, On 10/5/2013 8:22 AM:
> This looks very interesting to me:
> http://www.bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-6ah-lifepo4-battery
>
>
> On the surface it appears that I may be able to wire two of them in
> parallel (or series-parallel if individual cells) and enclose them in
> the battery case that fits in the tail of my LAK. I'll measure it today
> and see if there's a chance.

Be certain to read the user manual for this battery, which specifically
states series or parallel operation is not recommended! The manual also
states

"Only use 14.6V, LiFePO4 compatible chargers to charge the battery. The
charging current should be between 2A to 5A. If you need a charger,
please contact us"

Don't rely on claims for other Li batteries, like "any lead acid charger
can be used", but only go by the requirements of the manufacturer of the
battery you have.

Lithium based batteries must be taken more seriously than SLA
batteries, which are nearly identical from one manufacturer to another.
Lithium batteries, even LiFePO4, can vary substantially in their
characteristics, particularly with the type of BMS (battery management
system) installed in it, and may not even have one. Even the proper
storage varies considerably between Li and lead batteries.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Dan Marotta]

Thanks, Chris

The batteries I'm looking at have a PCM/BMS built into each and the price
includes a charger. I just measured my tail battery case and it will easily
hold two BLF-1206T, 12V 6 AH units.

Then I read the spec sheet and found that the manufacturer does not
recommend parallel (or series) connections. I've sent them a message
including the dimensions of my battery compartments and asking for
suggestions.

I know they have a 9 AH battery that will fit in my baggage compartment
battery holder and a 6 AH battery that will fit in the tail, but I want
more. I estimate my current power requirements at 1.8 amp hours so, for a 5
hour flight, I'd need 7.2 amp hours. I guess a 9 Ah battery with a 6 Ah
backup in the tail would work for just about any flight I might want to do,
but as I said... I want plenty of power.


"Chris Nicholas" > wrote in message
...
> Dan, not wishing to teach granny to suck eggs, but if you go for
> Lipo in the tail (or anywhere), make sure you have a proper
> battery management system in addition to a charger â?" apparently
> the significant number of fires in Lipos in model aircraft were due to
> inadequate or absent BMS. Otherss here will have more first-hand
> knowledge.
>
> (The Lak FES comes with a proper BMS for this very reason.)
>
>
> Chris N
>
>

[Morgans[_2_]]

"Dan Marotta" > wrote
>
> Then I read the spec sheet and found that the manufacturer does not
> recommend parallel (or series) connections. I've sent them a message
> including the dimensions of my battery compartments and asking for
> suggestions.

If you talk to the other people (like RC) guys, discharge is not the
problem, but it is in the charging. If you were to put two packs in
parallel, provide a Y plug so that you can charge each isolated from the
other.

Jim in NC

[Eric Greenwell[_4_]]

Morgans wrote, On 10/6/2013 8:15 PM:
>
>
> "Dan Marotta" > wrote
>>
>> Then I read the spec sheet and found that the manufacturer does not
>> recommend parallel (or series) connections. I've sent them a message
>> including the dimensions of my battery compartments and asking for
>> suggestions.
>
> If you talk to the other people (like RC) guys, discharge is not the
> problem, but it is in the charging. If you were to put two packs in
> parallel, provide a Y plug so that you can charge each isolated from the
> other.

It's OK to talk to the RC guys, but PLEASE follow the battery
manufacturer's recommendations instead of the RC guys. The RC guys are
using different chemistries, typically discharge rapidly (15-20
minutes), recharge rapidly, use special chargers, and do not use a BMS
(battery management system).

In addition, some of the things you know about SLA batteries can cause
you trouble when applied to Lithium batteries. Don't guess - look at the
instructions and data sheets, and talk to the manufacturer. Even the
people selling them might not be knowledgeable enough, because this is
new territory for us.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[son_of_flubber]

Please correct me if I got this wrong:

1.LiFePO4 with BMS are less likely to self-ignite compared to other lithium based batteries (or LiFEPO4 without BMS). But LiFePO4 still contain lithium and will make an intense and difficult to extinguish fire should they inadvertently ignite.

2.If an undamaged LiFePO4 battery self-ignites, it is most likely to occur during charging due to a malfunctioning charger or BMS. The battery overheats to the point of ignition due to internal resistance to the current applied by the battery charger.

3.If a LiFePO4 battery is charged while it is in a battery box, it may reach a higher temperature due to a reduced ability to dissipate heat to the surrounding environment. If it is a hot day or if the glider is in the sun, the charging battery will reach a higher temperature.

4.BMS have a fail-safe method of monitoring battery temperature. The BMS will suspend or reduce charging current should the battery temperature exceed a safe level.

5.The BMS makes charging a LiFePO4 battery, without removing it from the battery box in the glider, a safe operation. Manufacturers anticipate this scenario.

6.If I have a 5 AMP master fuse at my LiFePO4 battery terminals and I have a partial short that draws 4.5 AMPs. The BMS will detect any dangerous temperature rise and disconnect the circuit.

7.If the BMS is damaged in an accident, mishandling, or by age-related component failure, all bets are off. A LiFePO4 battery with a damaged BMS will be obviously "dead".

[son_of_flubber]

8.LiFePO4 batteries with BMS are compatible with solar panel chargers.

[Dan Marotta]

Thanks. When I finally make contact with the manufacturer, I'll bring that
up.

In the meantime, I'm thinking of fishing another pair of wires from the tail
to the cockpit. Since it appears that I can stick two of these 6 Ah
batteries in my tail battery box (which then slides into a compartment in
the tail), it should be simple to add another switch to the panel to control
it. I think two of these batteries are about the same weight as the three
SLAs in the box now and, due to their shorter length, would lower the mass
deeper into the fin.

"Morgans" > wrote in message
...
>
>
> "Dan Marotta" > wrote
>>
>> Then I read the spec sheet and found that the manufacturer does not
>> recommend parallel (or series) connections. I've sent them a message
>> including the dimensions of my battery compartments and asking for
>> suggestions.
>
> If you talk to the other people (like RC) guys, discharge is not the
> problem, but it is in the charging. If you were to put two packs in
> parallel, provide a Y plug so that you can charge each isolated from the
> other.
>
> Jim in NC

[Dan Marotta]

Eric, I have absolute faith in my ram air parachute. Having said that, I
don't relish the idea of bailing out of a flaming glider!

Since I have no direct knowledge of these new-fangled batteries, I will
listen only to the manufacturer when designing my system. When and if I get
it done, I'll post the design.


"Eric Greenwell" > wrote in message
...
> Morgans wrote, On 10/6/2013 8:15 PM:
>>
>>
>> "Dan Marotta" > wrote
>>>
>>> Then I read the spec sheet and found that the manufacturer does not
>>> recommend parallel (or series) connections. I've sent them a message
>>> including the dimensions of my battery compartments and asking for
>>> suggestions.
>>
>> If you talk to the other people (like RC) guys, discharge is not the
>> problem, but it is in the charging. If you were to put two packs in
>> parallel, provide a Y plug so that you can charge each isolated from the
>> other.
>
> It's OK to talk to the RC guys, but PLEASE follow the battery
> manufacturer's recommendations instead of the RC guys. The RC guys are
> using different chemistries, typically discharge rapidly (15-20 minutes),
> recharge rapidly, use special chargers, and do not use a BMS (battery
> management system).
>
> In addition, some of the things you know about SLA batteries can cause you
> trouble when applied to Lithium batteries. Don't guess - look at the
> instructions and data sheets, and talk to the manufacturer. Even the
> people selling them might not be knowledgeable enough, because this is new
> territory for us.
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email
> me)

[Soartech]

On Saturday, Dan Marotta wrote:
> This looks very interesting to me:
>
> http://www.bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-6ah-lifepo4-battery
>
Here is another one you might take a look at if considering Lithium power. I have one of these on my other flying machine and it works well.

http://shoraipower.com/products

[Evan Ludeman[_4_]]

On Monday, October 7, 2013 12:44:54 PM UTC-4, Soartech wrote:
> On Saturday, Dan Marotta wrote:
>
> > This looks very interesting to me:
>
> >
>
> > http://www.bioennopower.com/collections/12v-series-lifepo4-batteries/products/12v-6ah-lifepo4-battery
>
> >
>
> Here is another one you might take a look at if considering Lithium power. I have one of these on my other flying machine and it works well.
>
>
>
> http://shoraipower.com/products

You should explain what Shorai means by (for example) "18 AH PbEQ" before you make such a recommendation. But I predict that once you understand this well enough to explain it, you'll withdraw the recommendation :-).

These are starter batteries. Unsuited for gliders.

T8

[son_of_flubber]

On Monday, October 7, 2013 1:08:14 PM UTC-4, Evan Ludeman wrote:

> These are starter batteries. Unsuited for gliders.

From the Shorai FAQ:
.... Not only do they have less than 1/3 the internal resistance per capacity than do lead-acid, they are also the ultimate "deep-cycle" battery.

The internal "completely discharged" capacity of a Shorai LFX is 1/3 the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah cells internally. But the cells are capable of 80% discharge without damage and while retaining more cranking ability. As such, the USABLE capacity(or "reserve capacity") of an LFX18 12V battery is on or very near par with 18AHr-rated lead acid batteries, while providing superior cranking performance and a vast reduction in weight. The Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows users to compare a very different technology from lead-acid, but on a close apples-to-apples basis when making a choice.

[jfitch]

SLA batteries can (and usually are in glider service) discharged 80% DODC or even further. It will shorten their cycle life, perhaps to only 100 cycles or so. Important for only the most active of pilots. For normal pilots the batter will suffer degradation from time than cycles.

I think the main advantage of Li Ion (for a glider battery) is higher energy density, and a flatter voltage discharge curve. I sure hope the "lead acid equivalent amp hours" rating method does not catch on in the industry. Legal lying is what it is, praying mainly on the ignorant.

[Eric Greenwell[_4_]]

son_of_flubber wrote, On 10/7/2013 10:17 AM:
> On Monday, October 7, 2013 1:08:14 PM UTC-4, Evan Ludeman wrote:
>
>> These are starter batteries. Unsuited for gliders.
>
> From the Shorai FAQ: ... Not only do they have less than 1/3 the
> internal resistance per capacity than do lead-acid, they are also the
> ultimate "deep-cycle" battery.
>
> The internal "completely discharged" capacity of a Shorai LFX is 1/3
> the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah
> cells internally. But the cells are capable of 80% discharge without
> damage and while retaining more cranking ability. As such, the USABLE
> capacity(or "reserve capacity") of an LFX18 12V battery is on or very
> near par with 18AHr-rated lead acid batteries, while providing
> superior cranking performance and a vast reduction in weight. The
> Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows
> users to compare a very different technology from lead-acid, but on a
> close apples-to-apples basis when making a choice.

Shorai is telling you their starter batteries are GREAT starter
batteries, but they are still intended only for engine starting, which
is why they have the slogan "The World’s Lightest Strongest Powersports
Batteries". They have one-third (0.333) the capacity of a 12 volt, 18 AH
SLA at the 20 hour rate (6AH/Shorai vs 18AH/SLA), the rate that makes
sense when looking for glider batteries.

Shorai's "equivalent" means "equal starting ability". The "reserve
rating" term is used for starter batteries (high currents), not energy
storage batteries (high capacity). For example, the K2 will supply it's
AH rating, but is unsuitable for engine starting, because it has a 30
amp max current output; above that, the BMS will shut it off.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Eric Greenwell[_4_]]

Dan Marotta wrote, On 10/7/2013 9:16 AM:
> Eric, I have absolute faith in my ram air parachute. Having said that,
> I don't relish the idea of bailing out of a flaming glider!
>
> Since I have no direct knowledge of these new-fangled batteries, I will
> listen only to the manufacturer when designing my system. When and if I
> get it done, I'll post the design.

I look forward to reading your results.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Eric Greenwell[_4_]]

son_of_flubber wrote, On 10/7/2013 8:22 AM:
> 8.LiFePO4 batteries with BMS are compatible with solar panel chargers.

Most solar panel charge regulators use a pulsing output, which may not
be compatible with a BMS. Definitely determine this by asking the
manufacturer, or maybe it's in their data sheet. The regulators I'm
familiar with are intended for direct connection to lead-acid batteries.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[son_of_flubber]

On Monday, October 7, 2013 2:43:53 PM UTC-4, Eric Greenwell wrote:

> Shorai is telling you their starter batteries are GREAT starter
>
> batteries, but they are still intended only for engine starting, which
>
> is why they have the slogan "The World’s Lightest Strongest Powersports
>
> Batteries". They have one-third (0.333) the capacity of a 12 volt, 18 AH
>
> SLA at the 20 hour rate (6AH/Shorai vs 18AH/SLA), the rate that makes
>
> sense when looking for glider batteries.
>
>
>
> Shorai's "equivalent" means "equal starting ability". The "reserve
>
> rating" term is used for starter batteries (high currents), not energy
>
> storage batteries (high capacity). For example, the K2 will supply it's
>
> AH rating, but is unsuitable for engine starting, because it has a 30
>
> amp max current output; above that, the BMS will shut it off.
>

So when Shorai boasts of being 'the ultimate "deep-cycle" battery.', they are referring to something different than what you call "energy storage batteries (high capacity)? I thought a "deep-cycle" battery was what we were looking to use in a glider.

[Eric Greenwell[_4_]]

son_of_flubber wrote, On 10/7/2013 12:50 PM:
> On Monday, October 7, 2013 2:43:53 PM UTC-4, Eric Greenwell wrote:
>
>> Shorai is telling you their starter batteries are GREAT starter
>>
>> batteries, but they are still intended only for engine starting,
>> which
>>
>> is why they have the slogan "The World’s Lightest Strongest
>> Powersports
>>
>> Batteries". They have one-third (0.333) the capacity of a 12 volt,
>> 18 AH
>>
>> SLA at the 20 hour rate (6AH/Shorai vs 18AH/SLA), the rate that
>> makes
>>
>> sense when looking for glider batteries.
>>
>>
>>
>> Shorai's "equivalent" means "equal starting ability". The "reserve
>>
>> rating" term is used for starter batteries (high currents), not
>> energy
>>
>> storage batteries (high capacity). For example, the K2 will supply
>> it's
>>
>> AH rating, but is unsuitable for engine starting, because it has a
>> 30
>>
>> amp max current output; above that, the BMS will shut it off.
>>
>
> So when Shorai boasts of being 'the ultimate "deep-cycle" battery.',
> they are referring to something different than what you call "energy
> storage batteries (high capacity)? I thought a "deep-cycle" battery
> was what we were looking to use in a glider.

"Deep-cycle" is what we want for a glider battery. I have no idea why
they say that it's the "ultimate" deep-cycle battery; elsewhere, they
clearly state it's for "powersports" applications and the warranty is
void for other uses. "Powersports" means sKidoos, seadoos, motorcycles,
etc. It's very confusing until you realize what is going on.

They do show the AH ratings, and you can see how small they are. The
batteries might actually be suitable for "deep-cycle" use, but be aware
that buying an 18 AH "equivalent" unit gets you only 6 AH of deep-cycle
output.

There is another issue: I don't think they have a BMS in their battery,
and that's why they have strict requirements for the charging system
voltages, and any vehicle with parasitic drains (engine computer, clock,
etc) when it's not running also voids the warranty. Why? No BMS to shut
off the battery if it's drained too low.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Evan Ludeman[_4_]]

I made some notes in the process of educating myself on LFP batteries last Winter. I've tried to condense them here into something semi-useful.

A non-exhaustive list of things to ask of LFP battery vendors:

1. Get the component cell spec sheets. Especially look for specs on failure modes due to abuse, e.g. short circuits, crushing, piercing. You absolutely want cells that can survive all of this without self ignition. They *will* get hot if shorted in some fashion which is something to keep in mind when finding a home for an LFP battery in your glider. The spec sheets may give you an idea of how hot, probably for a single cell. If the manufacturer has really done their homework, maybe they'll know what a worst case temperature excursion is for the whole pack (you probably won't like the answer).

2. Get the specs on the BMS. You absolutely need under charge & over charge protection. You want a BMS that monitors *individual* cell voltages, not just the whole pack. Internal cell balancing highly recommended (not all BMS do this).

3. Get the specs on charge, discharge and storage requirements. Make certain these specs work for you and your application. These specs will be a function of the BMS as well as the battery. If you fly in wave, try to get some data on low temperature operation.

4. Get as much detail as you can on packaging. I think a sealed ABS case is a minimum requirement for aviation use of any sort, but anything that enhances ruggedness and makes internal damage of any kind less likely over the long haul is a good thing. Here's an interesting dissection of a K2 battery

http://www.etotheipiplusone.net/?p=1991

-Evan Ludeman / T8

[JS]

Mark et al:
The accu24.de website has the batteries exactly as you can order through Schempp-Hirth. Model number 8000910PSHMPXM is the 12V 10A/H that not only fits but already has the cover that the Schempp battery holders will clip into and the same connector supplied on the Arcus, Quintus and other current production gliders (V2CxM etc).
Or of course you can call Kirchheim. They have the LiFePO4 battery option for everything but motor starting.
And Eric, the Strobl 2-panel 15W array works very well. Had that on 26015 and now on 27053. Does better with LiFePO4, as they seem to charge more efficiently.

The direct link to the ready-to-go Schempp battery might be too long, so here's a tinyurl.
Jim

http://tinyurl.com/kbfjm8p

On Friday, October 4, 2013 10:36:16 AM UTC-7, waremark wrote:
> Can someone recommend the best LifePo battery which fits in a completely standard bracket? (In my case for an Arcus M - I have 4 Strobl panels which are supposed to generate 2.4 Ah, but I have the max amount of electronics fitted - I have not run out of power yet with 2 ordinary 7Ah gel cells, but think I might run out if a flight lasted for more than 8 hours).
>
>
>
> Thanks for any advice, Mark Burton, 4M, London Gliding Club, UK

[son_of_flubber]

On Monday, October 7, 2013 7:25:28 PM UTC-4, Evan Ludeman wrote:
> I made some notes in the process of educating myself on LFP batteries last Winter. I've tried to condense them here into something semi-useful.

Oh man. Flying around with two or three cheap plastic buckets filled with hydrochloric acid and lead seems the way go for now (unless you really really need the power capacity).

[6PK]

On Monday, October 7, 2013 7:19:32 PM UTC-7, son_of_flubber wrote:
> On Monday, October 7, 2013 7:25:28 PM UTC-4, Evan Ludeman wrote:
>
> > I made some notes in the process of educating myself on LFP batteries last Winter. I've tried to condense them here into something semi-useful.
>
>
>
> Oh man. Flying around with two or three cheap plastic buckets filled with hydrochloric acid and lead seems the way go for now (unless you really really need the power capacity).

Just received my order of the LiFePO4 battery. The first thing on the box in large print; "LITHIUM BATTERIES- FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL"
Hmmmm......?

[[email protected]]

> Just received my order of the LiFePO4 battery. The first thing on the box in large print; "LITHIUM BATTERIES- FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL"
>
> Hmmmm......?


Where did you order them from?

[[email protected]]

On Tuesday, October 8, 2013 11:33:56 AM UTC-4, 6PK wrote:
> On Monday, October 7, 2013 7:19:32 PM UTC-7, son_of_flubber wrote: > On Monday, October 7, 2013 7:25:28 PM UTC-4, Evan Ludeman wrote: > > > I made some notes in the process of educating myself on LFP batteries last Winter. I've tried to condense them here into something semi-useful. > > > > Oh man.. Flying around with two or three cheap plastic buckets filled with hydrochloric acid and lead seems the way go for now (unless you really really need the power capacity). Just received my order of the LiFePO4 battery. The first thing on the box in large print; "LITHIUM BATTERIES- FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL" Hmmmm......?

I got an ELT with the same warning on the outside of the box due to the lithium battery used in the remote display.
Go figure.
UH

[Dan Marotta]

It's that pesky "Hazardous Cargo" thing. Same thing goes for dry ice, hair
spray, and oxygen generators stacked on top of magnesium wheels in the cargo
compartment.

I'm seriously considering a 12v 6Ah LiFePO4 pack (or two) wrapped in (gasp)
shrink wrap for my tail compartment. But they will be fitted inside of a
carbon case.


"6PK" > wrote in message
...
> On Monday, October 7, 2013 7:19:32 PM UTC-7, son_of_flubber wrote:
>> On Monday, October 7, 2013 7:25:28 PM UTC-4, Evan Ludeman wrote:
>>
>> > I made some notes in the process of educating myself on LFP batteries
>> > last Winter. I've tried to condense them here into something
>> > semi-useful.
>>
>>
>>
>> Oh man. Flying around with two or three cheap plastic buckets filled with
>> hydrochloric acid and lead seems the way go for now (unless you really
>> really need the power capacity).
>
> Just received my order of the LiFePO4 battery. The first thing on the box
> in large print; "LITHIUM BATTERIES- FORBIDDEN FOR TRANSPORT ABOARD
> AIRCRAFT AND VESSEL"
> Hmmmm......?

[Eric Greenwell[_4_]]

Dan Marotta wrote, On 10/8/2013 9:40 AM:
> It's that pesky "Hazardous Cargo" thing. Same thing goes for dry ice,
> hair spray, and oxygen generators stacked on top of magnesium wheels in
> the cargo compartment.
>
> I'm seriously considering a 12v 6Ah LiFePO4 pack (or two) wrapped in
> (gasp) shrink wrap for my tail compartment. But they will be fitted
> inside of a carbon case.

I think you should consider these batteries instead.

http://www.starkpower.com/

They do allow parallel connection, come with what appears to be a
substantial case, a complete BMS, make a clear distinction between their
starter and energy storage batteries, offer compatible chargers, and the
prices seem reasonable.

I have no direct knowledge about the company or the batteries, but it is
the best website I've seen for the kind of batteries we are interested
in. There is more detailed information about the batteries, and that
gives me more confidence than the rather sparse websites K2 and the
others have.

They also offer more choices in sizes and amp hours, and can be
purchased off the Amazon website (same price, though).

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Eric Greenwell[_4_]]

son_of_flubber wrote, On 10/7/2013 8:10 AM:
> Please correct me if I got this wrong:
>
> 1.LiFePO4 with BMS are less likely to self-ignite compared to other
> lithium based batteries (or LiFEPO4 without BMS). But LiFePO4 still
> contain lithium and will make an intense and difficult to extinguish
> fire should they inadvertently ignite.
>
> 2.If an undamaged LiFePO4 battery self-ignites, it is most likely to
> occur during charging due to a malfunctioning charger or BMS. The
> battery overheats to the point of ignition due to internal resistance
> to the current applied by the battery charger.
>
> 3.If a LiFePO4 battery is charged while it is in a battery box, it
> may reach a higher temperature due to a reduced ability to dissipate
> heat to the surrounding environment. If it is a hot day or if the
> glider is in the sun, the charging battery will reach a higher
> temperature.
>
> 4.BMS have a fail-safe method of monitoring battery temperature. The
> BMS will suspend or reduce charging current should the battery
> temperature exceed a safe level.
>
> 5.The BMS makes charging a LiFePO4 battery, without removing it from
> the battery box in the glider, a safe operation. Manufacturers
> anticipate this scenario.
>
> 6.If I have a 5 AMP master fuse at my LiFePO4 battery terminals and I
> have a partial short that draws 4.5 AMPs. The BMS will detect any
> dangerous temperature rise and disconnect the circuit.
>
> 7.If the BMS is damaged in an accident, mishandling, or by
> age-related component failure, all bets are off. A LiFePO4 battery
> with a damaged BMS will be obviously "dead".

I don't know enough about LiFe batteries to give you good answers, but
this website is the best I've found of the consumer suppliers:

http://www.starkpower.com/index.php

Note that they clearly separate their "starter" batteries from their
"energy storage" batteries. Here is the link to their instructions:

http://www.starkpower.com/2013test/UltraEnergy_Manual_Warrany.pdf

This page has the details for their energy storage batteries.

http://www.starkpower.com/spnews/energystoragebatt/

I notice they use some very pessimistic values for lead acid batteries
in their comparison table with LiFe batteries, in addition to using
"flooded" batteries instead SLA batteries for the comparison.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[6PK]

On Tuesday, October 8, 2013 8:55:56 AM UTC-7, wrote:
> > Just received my order of the LiFePO4 battery. The first thing on the box in large print; "LITHIUM BATTERIES- FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL"
>
> >
>
> > Hmmmm......?
>
>
>
>
>
> Where did you order them from?

Bioenno Power

[Dan Marotta]

Thanks, but I couldn't find any on that site which will work in my tail
application. The tail battery box (removeable) measures 22 11/16 L x 1
7/16 inchesW x 3 H. It holds three of these wired in parallel:
http://www.batteriesplus.com/product/32623-WKA12--2-dot3F-12V-2-dot3Ah-Werker-Battery-with-F1-Terminal/100085-1/102629-SLA-Sealed-Lead-Acid-Batteries/102645-Werker/12V.aspx.

I'm going to hold off for a while with LiFePO4 batteries. I began to
suspect my master switch as my problem and replaced it today with a much
more robust switch. We'll see how that works out.


"Eric Greenwell" > wrote in message
...
> Dan Marotta wrote, On 10/8/2013 9:40 AM:
>> It's that pesky "Hazardous Cargo" thing. Same thing goes for dry ice,
>> hair spray, and oxygen generators stacked on top of magnesium wheels in
>> the cargo compartment.
>>
>> I'm seriously considering a 12v 6Ah LiFePO4 pack (or two) wrapped in
>> (gasp) shrink wrap for my tail compartment. But they will be fitted
>> inside of a carbon case.
>
> I think you should consider these batteries instead.
>
> http://www.starkpower.com/
>
> They do allow parallel connection, come with what appears to be a
> substantial case, a complete BMS, make a clear distinction between their
> starter and energy storage batteries, offer compatible chargers, and the
> prices seem reasonable.
>
> I have no direct knowledge about the company or the batteries, but it is
> the best website I've seen for the kind of batteries we are interested in.
> There is more detailed information about the batteries, and that gives me
> more confidence than the rather sparse websites K2 and the others have.
>
> They also offer more choices in sizes and amp hours, and can be purchased
> off the Amazon website (same price, though).
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email
> me)

[Tom[_12_]]

I hesitate to enter this conversation, however, some of you may want to know we have been selling Lithium Iron Phosphate (LiFePO4) batteries with great success and no complaints. One word of caution is you need to use a special, inexpensive battery charger for this type of battery.

See www.eglider.org

Tom Knauff

[GC[_2_]]

On 8/10/2013 04:17, son_of_flubber wrote:

> The internal "completely discharged" capacity of a Shorai LFX is 1/3
> the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah
> cells internally. But the cells are capable of 80% discharge without
> damage and while retaining more cranking ability. As such, the USABLE
> capacity(or "reserve capacity") of an LFX18 12V battery is on or very
> near par with 18AHr-rated lead acid batteries, while providing
> superior cranking performance and a vast reduction in weight. The
> Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows
> users to compare a very different technology from lead-acid, but on a
> close apples-to-apples basis when making a choice.

So they say. In the famous words of Miss Mandy Rice-Davies "They would
say that wouldn't they".

BTW - how big is "vast"?

GC

[Eric Greenwell[_4_]]

GC wrote, On 10/23/2013 2:18 AM:
> On 8/10/2013 04:17, son_of_flubber wrote:
>
>> The internal "completely discharged" capacity of a Shorai LFX is 1/3
>> the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah
>> cells internally. But the cells are capable of 80% discharge without
>> damage and while retaining more cranking ability. As such, the USABLE
>> capacity(or "reserve capacity") of an LFX18 12V battery is on or very
>> near par with 18AHr-rated lead acid batteries, while providing
>> superior cranking performance and a vast reduction in weight. The
>> Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows
>> users to compare a very different technology from lead-acid, but on a
>> close apples-to-apples basis when making a choice.
>
> So they say. In the famous words of Miss Mandy Rice-Davies "They would
> say that wouldn't they".
>
> BTW - how big is "vast"?

According to Shorai, it's about a 5:1 weight reduction. That's also a
clue to why they aren't good for energy storage: there just isn't enough
material inside the case to store the energy you expect for the
"[equivalent] amp hour rating". A typical Li-Fe battery will weigh about
half of what an SLA weighs for a given amp hour capacity.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[son_of_flubber]

On Wednesday, October 23, 2013 5:18:15 AM UTC-4, GC wrote:
> On 8/10/2013 04:17, son_of_flubber wrote:
>
>
>
> > The internal "completely discharged" capacity of a Shorai LFX is 1/3
>
> > the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah
>
> > cells internally. But the cells are capable of 80% discharge without
>
> > damage and while retaining more cranking ability. As such, the USABLE
>
> > capacity(or "reserve capacity") of an LFX18 12V battery is on or very
>
> > near par with 18AHr-rated lead acid batteries, while providing
>
> > superior cranking performance and a vast reduction in weight. The
>
> > Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows
>
> > users to compare a very different technology from lead-acid, but on a
>
> > close apples-to-apples basis when making a choice.
>
>
>
> So they say. In the famous words of Miss Mandy Rice-Davies "They would
>
> say that wouldn't they".
>
> GC

Shori confirmed by email that they only make batteries for "starting applications". We knew that but it is good that they admit it.

The marketing people always lie and for that reason I do not judge a battery by its website.

Maybe we will see some new products come up for Spring.

[[email protected]]

On Wednesday, October 2, 2013 11:46:32 AM UTC-6, John Marshall wrote:
> I need advice about the best choice of batteries for an asg 29e. lithium
>
> ion would be outside manufacturer's remit and the insurer's plus too many
>
> risks-the fuel tank is directly above the battery housings. I would like
>
> something with at least 9 amp hours, whether gel cell or mh.

Maybe this is way off track - but maybe you have a transponder ?
if most transponders are not specially programmed (set up) they will
run all the time - they are "on" all of the time - drawing power even
when your panel read out says "off" - I had that problem in 2 gliders -
EB28 Edition - another solution to check this power loss is to unplug
the transponder and see if that solves the problem - if it does then
get out your manual and find out how to change the settings - good luck

[[email protected]]

On Wednesday, October 2, 2013 11:46:32 AM UTC-6, John Marshall wrote:
> I need advice about the best choice of batteries for an asg 29e. lithium
>
> ion would be outside manufacturer's remit and the insurer's plus too many
>
> risks-the fuel tank is directly above the battery housings. I would like
>
> something with at least 9 amp hours, whether gel cell or mh.

from another posting -

I did, however, get behind my panel last week and changed out my master
switch for one more substantial in current capability and have experienced a
major improvement in function of my equipment. The switch that was
installed when I bought the glider was adequate for the CAI302 and the
MicroAir 760 but, after installing a Trig transponder, a Dell Steak and a
Zaon MRX, all operated from the same bus, the current capacity of the master
switch was the limiting factor. After two flights with the new master
switch installed it would appear that the problem is solved.

[Dave Nadler]

On Wednesday, October 23, 2013 8:15:26 PM UTC-4, wrote:
> if most transponders are not specially programmed (set up) they will
> run all the time - they are "on" all of the time - drawing power even
> when your panel read out says "off"

Say what ? A transponder should draw very little power except
when it is transmitting, which it only does when interrogated.
A Mode S transponder draws less than Mode C as it responds to
selective (fewer) interrogations (yes Daryll, I'm simplifying).
The only notable draw for a transponder installation would be a
poor quality encoder (older models have power-hungry heaters
rather than temperature-compensated altitude transducers);
should not be a problem for modern units...

Perhaps you can email me offline make/model of the setup
which gave you power problems?

Hope that helps,
Best Regards, Dave

[Dan Marotta]

When I turn my master switch off, power is removed from the DC bus. My
transponder is powered from the bus.

Switch off = no power drain.


> wrote in message
...
> On Wednesday, October 2, 2013 11:46:32 AM UTC-6, John Marshall wrote:
>> I need advice about the best choice of batteries for an asg 29e. lithium
>>
>> ion would be outside manufacturer's remit and the insurer's plus too many
>>
>> risks-the fuel tank is directly above the battery housings. I would like
>>
>> something with at least 9 amp hours, whether gel cell or mh.
>
> Maybe this is way off track - but maybe you have a transponder ?
> if most transponders are not specially programmed (set up) they will
> run all the time - they are "on" all of the time - drawing power even
> when your panel read out says "off" - I had that problem in 2 gliders -
> EB28 Edition - another solution to check this power loss is to unplug
> the transponder and see if that solves the problem - if it does then
> get out your manual and find out how to change the settings - good luck

[JS]

Mode C Transponders I've used have a heater in the separate altitude encoder. This is a factor whenever the unit is turned on.
Jim