Battery Source

David Kinsell wrote:
Happy?? With a fresh battery, they work for a while, but die after only
part of the rated capacity is used up. Understanding such a complex
issue is way beyond the comprehension of most glider pilots, apparently.

Dave,

I prefer 14 volt batteries and used them for many years. But I've used
12 volts in my ASW 24 for nearly 14 years with no problems. Currently
(no pun intended), I'm running a Dittel radio, LNAV, GPS-NAV, and
Compaq Aero 1550 with a common 7 amp-hour sealed lead-acid cell. If I
add a transponder, I'll be looking to add a battery but until then I'm
OK. The second battery in the vertical fin (i.e., what Mike is seeking)
is a backup that I've only used a few times when my primary battery was
failing (as in: I had to buy a new one). I've had experts tell me
(somewhat more politely) that 14 volts doesn't really buy me much
unless I increase the amp-hour capacity of the battery pack. My
response was always that radio transmitters start to perform badly
below about 11 volts even if everything else works OK down to, say, 9v,
so 14 volts gives me a little more transmit time (and I think that's
what your point is). The battery box in my '24 holds a 12v cell nicely,
however, so that's what I use. I saw a slightly taller 12v battery with
significantly more amp-hours recently that would also fit but haven't
heard whether it's real or just marketing hype. [Larry, were you going
to report on the PowerSonic PSH-12100 10.5 AH battery?]

Speaking of preferences, so is top (or bottom) posting. I agree that
bottom posting (i.e., adding one's response after the quoted text from
the previous author's posting rather than before) is a recommended
convention. But top posting isn't on my personal list of "most annoying
things on the Usenet." A lot of folks (including me) use Google Groups
to read newsgroups so top posting works fine: quoted text is [mostly]
suppressed anyway so each posting follows the previous one and
preserves the order in which people read them. If I'm responding
point-by-point, I'll bottom post or interleave quoted text with
responses but it's situational. And strictly a preference, not a
requirement.

Perhaps at the top of my own list of most annoying things on the Usenet
is people who insult or belittle readers in an attempt to advance their
own views. I'm being harsh on you because you've made a number of
excellent contributions to this group in the past. Apparently this
thread hit a couple of sensitive points. If I may offer a suggestion,
it's that readers still tend to weigh the merits of what one says with
less regard for the vehemence with which it's expressed.

So in an agitated exchange, the message survives. What suffers is one's
reputation for civility. I'd be unhappy to see this occur to any of the
valued and knowledgeable contributors to this group.

Chip Bearden

David Kinsell wrote:
Happy?? With a fresh battery, they work for a while, but die after only
part of the rated capacity is used up. Understanding such a complex
issue is way beyond the comprehension of most glider pilots, apparently.

Dave,

I prefer 14 volt batteries and used them for many years. But I've used
12 volts in my ASW 24 for nearly 14 years with no problems. Currently
(no pun intended), I'm running a Dittel radio, LNAV, GPS-NAV, and
Compaq Aero 1550 with a common 7 amp-hour sealed lead-acid cell. If I
add a transponder, I'll be looking to add a battery but until then I'm
OK. The second battery in the vertical fin (i.e., what Mike is seeking)
is a backup that I've only used a few times when my primary battery was
failing (as in: I had to buy a new one). I've had experts tell me
(somewhat more politely) that 14 volts doesn't really buy me much
unless I increase the amp-hour capacity of the battery pack. My
response was always that radio transmitters start to perform badly
below about 11 volts even if everything else works OK down to, say, 9v,
so 14 volts gives me a little more transmit time (and I think that's
what your point is). The battery box in my '24 holds a 12v cell nicely,
however, so that's what I use. I saw a slightly taller 12v battery with
significantly more amp-hours recently that would also fit but haven't
heard whether it's real or just marketing hype. [Larry, were you going
to report on the PowerSonic PSH-12100 10.5 AH battery?]

Speaking of preferences, so is top (or bottom) posting. I agree that
bottom posting (i.e., adding one's response after the quoted text from
the previous author's posting rather than before) is a recommended
convention. But top posting isn't on my personal list of "most annoying
things on the Usenet." A lot of folks (including me) use Google Groups
to read newsgroups so top posting works fine: quoted text is [mostly]
suppressed anyway so each posting follows the previous one and
preserves the order in which people read them. If I'm responding
point-by-point, I'll bottom post or interleave quoted text with
responses but it's situational. And strictly a preference, not a
requirement.

Perhaps at the top of my own list of most annoying things on the Usenet
is people who insult or belittle readers in an attempt to advance their
own views. I'm being harsh on you because you've made a number of
excellent contributions to this group in the past. Apparently this
thread hit a couple of sensitive points. If I may offer a suggestion,
it's that readers still tend to weigh the merits of what one says with
less regard for the vehemence with which it's expressed.

So in an agitated exchange, the message survives. What suffers is one's
reputation for civility. I'd be unhappy to see this occur to any of the
valued and knowledgeable contributors to this group.

Chip Bearden

I am very pleased with the powersonic 8.5 ah battery which is exactly
the same size as the typical 7 ah battery. Running a 302, Ipaq, becker
3201 radio and becker transponder (with encoder) and on flights of up to
6 hours have yet to switch to the backup battery.

Bob

wrote:
David Kinsell wrote:

Happy?? With a fresh battery, they work for a while, but die after only
part of the rated capacity is used up. Understanding such a complex
issue is way beyond the comprehension of most glider pilots, apparently.


Dave,

I prefer 14 volt batteries and used them for many years. But I've used
12 volts in my ASW 24 for nearly 14 years with no problems. Currently
(no pun intended), I'm running a Dittel radio, LNAV, GPS-NAV, and
Compaq Aero 1550 with a common 7 amp-hour sealed lead-acid cell. If I
add a transponder, I'll be looking to add a battery but until then I'm
OK. The second battery in the vertical fin (i.e., what Mike is seeking)
is a backup that I've only used a few times when my primary battery was
failing (as in: I had to buy a new one). I've had experts tell me
(somewhat more politely) that 14 volts doesn't really buy me much
unless I increase the amp-hour capacity of the battery pack. My
response was always that radio transmitters start to perform badly
below about 11 volts even if everything else works OK down to, say, 9v,
so 14 volts gives me a little more transmit time (and I think that's
what your point is). The battery box in my '24 holds a 12v cell nicely,
however, so that's what I use. I saw a slightly taller 12v battery with
significantly more amp-hours recently that would also fit but haven't
heard whether it's real or just marketing hype. [Larry, were you going
to report on the PowerSonic PSH-12100 10.5 AH battery?]

Speaking of preferences, so is top (or bottom) posting. I agree that
bottom posting (i.e., adding one's response after the quoted text from
the previous author's posting rather than before) is a recommended
convention. But top posting isn't on my personal list of "most annoying
things on the Usenet." A lot of folks (including me) use Google Groups
to read newsgroups so top posting works fine: quoted text is [mostly]
suppressed anyway so each posting follows the previous one and
preserves the order in which people read them. If I'm responding
point-by-point, I'll bottom post or interleave quoted text with
responses but it's situational. And strictly a preference, not a
requirement.

Perhaps at the top of my own list of most annoying things on the Usenet
is people who insult or belittle readers in an attempt to advance their
own views. I'm being harsh on you because you've made a number of
excellent contributions to this group in the past. Apparently this
thread hit a couple of sensitive points. If I may offer a suggestion,
it's that readers still tend to weigh the merits of what one says with
less regard for the vehemence with which it's expressed.

So in an agitated exchange, the message survives. What suffers is one's
reputation for civility. I'd be unhappy to see this occur to any of the
valued and knowledgeable contributors to this group.

Chip Bearden

" wrote in message
ups.com:

David Kinsell wrote:
Happy?? With a fresh battery, they work for a while, but die after only
part of the rated capacity is used up. Understanding such a complex
issue is way beyond the comprehension of most glider pilots, apparently.

Dave,

I prefer 14 volt batteries and used them for many years. But I've used
12 volts in my ASW 24 for nearly 14 years with no problems. Currently
(no pun intended), I'm running a Dittel radio, LNAV, GPS-NAV, and
Compaq Aero 1550 with a common 7 amp-hour sealed lead-acid cell. If I
add a transponder, I'll be looking to add a battery but until then I'm
OK. The second battery in the vertical fin (i.e., what Mike is seeking)
is a backup that I've only used a few times when my primary battery was
failing (as in: I had to buy a new one). I've had experts tell me
(somewhat more politely) that 14 volts doesn't really buy me much
unless I increase the amp-hour capacity of the battery pack. My
response was always that radio transmitters start to perform badly
below about 11 volts even if everything else works OK down to, say, 9v,
so 14 volts gives me a little more transmit time (and I think that's
what your point is). The battery box in my '24 holds a 12v cell nicely,
however, so that's what I use. I saw a slightly taller 12v battery with
significantly more amp-hours recently that would also fit but haven't
heard whether it's real or just marketing hype. [Larry, were you going
to report on the PowerSonic PSH-12100 10.5 AH battery?]






Chip,



I bought and installed a couple of these before Uvalde. Have not had a
chance to 'characterize' them but they certainly lasted a lot longer
than the previous (admittedly older) smaller batteries.



So far, I am pleased.



Larry

Paul Remde wrote:
Hi David,

I highly recommend 12V systems in gliders. You can save yourself a lot of
money and hassle by using 12V batteries.

The design of radios has changed a lot in recent years. Good radios don't
require 14V batteries. Low cost and old radios do prefer 14V power.

Good Soaring,

Paul Remde


Mike et. al.

I used to be a "14 volter", using the old Gates Cells and later Sealed
Lead Acid. My new ship has all modern electronics (LNav, GPSNav,
Becker), and I have absolutely no issues running 12 Volts. I've
primarily used the Powersonic PSH-12100 (12V, 12AH) with good success.
I can easily get in a full weekend of flying (8-10hrs) on a single
charge. With reasonable care (storing in a cool, dry environment,
recharging after flying), they seem to last about 3-4 seasons (probably
about 150-200 cycles with my flying schedule). If you look at the
discharge charts, there's not a huge difference in useful time at our
typical discharge rates (on average less than 1 amp draw) between the
12AH and 10AH models, but it's only a couple of bucks more to buy the
higher capacity battery.

None of which, I guess, answers your original question.... The largest
capacity Powersonic that fits your specs is the PS-1229, which is only
2.9AH and 2.2lbs. Sufficient as a "get home" backup if you turn off
the radio but not what you'd want to run for a whole day of flying.
Also, in this case, there is some need to consider voltage drop across
the long wire you will have running back to the tail. You can make up
a 14 Volt kit by attaching an additional 2V 6AH cell that they have,
though in general they recommend matching the load ratings more
closely.

P3

David Kinsell wrote:
Mike the Strike wrote:

Thanks for all the suggestions. Actually, I've used 12-volt batteries
in all my gliders and never had a problem. This 12/14 V argument is
really unnecessary! Good German instruments like the Becker and Dittel
radios are quite happy with a 12-volt supply.


Happy?? With a fresh battery, they work for a while, but die after only
part of the rated capacity is used up. Understanding such a complex
issue is way beyond the comprehension of most glider pilots, apparently.

If your current batteries were working so well, I don't suppose you'd be
needing to add yet another one. Seems like the people who run 12 volts
are the ones always looking to find somewhere to cram more batteries
into their glider. Gee, I wonder why??


This response is worth replying to....Mike the Strike.....AKA a Chief
Scientist (PHD) in a consulting company specializing in Power Quality
and Electromagnetic Environment It’s my guess that he understands the
“Complex” issues involved in sailplane electrical systems.

David Kinsell wrote:

Happy?? With a fresh battery, they work for a while, but die after only
part of the rated capacity is used up. Understanding such a complex
issue is way beyond the comprehension of most glider pilots, apparently.

But not this one - electrical engineer for 33 years.

If your current batteries were working so well, I don't suppose you'd be
needing to add yet another one. Seems like the people who run 12 volts
are the ones always looking to find somewhere to cram more batteries
into their glider. Gee, I wonder why??

Maybe this will clear it up: they've added an Ipaq (250-500 ma), a
logger (100-200 ma), another vario (50-100 ma), a transponder (450-650
ma), a TPAS (50 ma?). Or they screwed up, left a switch on overnight,
ran the battery down, and decided they needed a backup. Or it's simply
inconvenient to charge everyday. Or they are obsessive. Or they needed
tail weight, and thought the lead back there might just as well be doing
something useful in a battery instead of just sitting there.

And since most glider pilots are using 12 volts, it isn't so strange
they are the ones we hear from. Also, it's my observation that the
gliders with the older radios and 14 volt battery, besides being a
smaller number each year as these radios die, simply aren't getting the
new equipment I've listed. They typically belong to a club or local
flyer that has no need for more equipment.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

David:

Complex?

Modern glider instruments (including radios) are designed to operate on
a nominal 12 V supply. My Dittel FSG-71 gives the voltage range as
13.8 V+ 10% -20%, which translates into 11 V to 15 V. My SN-10
specifies 10 V to 15 V.

A fully-charged lead-acid or gel has a voltage somewhere in the 12.5 V
range and drops to around 11.5 V as it is discharged to 50% of its
capacity. A voltage of 11 V or below means the battery is pretty much
dead - either old or over-drained. (Standard data gives final cell
voltage of 1.83 V for a moderately slowly-drained battery at normal
temperatures, but it could be lower).

Many low-voltage indication problems are not just battery issues but
wiring problems - thin wiring, corroded connectors with high-resistance
joints. (being such a smart guy, you're no doubt familiar with Ohm's
Law)

Of course, a 14 V battery will give you a bit more power and enable you
to run the batteries down further, but the tradeoff is usually a
cobbled-together non-standard battery stack that you can't charge with
an off-the-shelf charger.

In my Discus, my added batteries are nothing to do with lack of
performance of the existing system which is flawless, but I am adding a
power-hungry transponder. I am reconfiguring the batteries accordingly
and adding a fin battery as backup for my main panel instruments. I
need 6 pounds of weight in the tail anyway, so it makes more sense to
put a useful lead battery there than just dead weight.

Please keep your comments civil.

It's probably also worth noting that a 14volt pack hot off the charger
has a terminal voltage greater than 15 volts and will exceed the
maximum voltage specs for many modern glider systems.

Andy

"T o d d P a t t i s t" wrote:

Of course, a 14 V battery will give you a bit more power and enable you
to run the batteries down further, but the tradeoff is usually a
cobbled-together non-standard battery stack that you can't charge with
an off-the-shelf charger.

I've run 12 volts and I've run 14 volts. The charger
comment above is the main disadvantage of 14 volts. The
secondary disadvantage is the "non-standard battery stack"
may not want to fit into your standard-sized battery
location.

An advantage to 14 volt is more radio power/longer range on
transmit. Modern radios don't cut out at lower voltage, like
older radios that assumed 13.8 volts, but they all drive the
output stages off the full voltage - the more voltage, the
more output power.

Other advantages are that you can run the battery longer
before it gets too low, and for any switchmode DC-DC
downconverters, such as I use for my IPAQ's 5 volt
requirements, you get less current draw and the battery
lasts longer (which it should since you've got more stored
energy). For me, the advantages of 14 volts outweigh the
disadvantages on my primary battery (it fits into the space
available), but not for my backup battery (the larger 14
volt battery won't fit there.)

It ultimately comes down to preference.

I agree with above.
I fly with a Dittle Radio.
If the radio is on but I do not talk, my 7AH 12V battery lasts
about 4.5 hour with the usual LNav, logger and 1530 Ipaq.
The battery will read about 11.8 volts after that time. At that
point if I make a call on the radio the chances are I will not be
heard unless I am close to the field. That is due in large part
the hand held radios seem not to do very well when it comes
to receiving a call from a radio with lower battery power. I have
made it a habit of switching to the reserve battery for my final
glide and use this battery again the next day while I charge
up the other one over night. I had an experience recently
whereby heaved in the cockpit. I tried to make a call, that I
would land in about 1/2 hour. I needed a bucket of hot water
and clean closing. I was not received as I forgot to switch the
battery. Lucky for me my call was being relayed and my wife
was ready with the goods.
Regards
Udo