View Full Version : Experience with Lithium Iron Phosphate Glider batteries?
During the winter of 2009 I was bored, and aggravated with the sealed lead acid batteries that I was using in my sailplane. They didn't hold the voltage above 12v for very long, they needed replacement every few years, and I had one die 5 miles away from the airport at the end of a 300K badge flight. My argument that I had 2,000 FT over final glide at that point didn't sway the FAI from rejecting that flight for my badge attempt.
My search at the time led me to the K2 (Lithium Iron Phosphate chemistry)batteries that were the subject of my spring of 2010 battery article in Soaring.
Reaction to the article was mixed, and a partial retraction was printed the following month after an FAA DER (Designated Engineering Reviewer)with experience in certifying Lithium Ion batteries for some type of usage in commercial airliners, objected to the use of Lithium Iron Phosphate batteries in sailplanes because they hadn't been certified for that use by the FAA.
It's now 2016, and I see a lot of K2 batteries in other sailplanes. Soaring supply companies in the U.S. seem to be providing K2 batteries or a similar battery from a different manufacturer on a regular basis. The K2 battery I purchased in 2009, and it's twin purchased a year later, are still providing power to my sailplane without incident. There seems to be no degradation in performance, and other than switching to Anderson Power Pole connectors, I have not made any changes to my battery set up.
Has anyone out there had an issue with the usage of Lithium Iron Phosphate chemistry batteries in sailplanes?
Just curious because, a lot of dire consequences were predicted after my article came out.
SF
On Tuesday, May 17, 2016 at 12:58:47 PM UTC-4, SF wrote:
> During the winter of 2009 I was bored, and aggravated with the sealed lead acid batteries that I was using in my sailplane. They didn't hold the voltage above 12v for very long, they needed replacement every few years, and I had one die 5 miles away from the airport at the end of a 300K badge flight. My argument that I had 2,000 FT over final glide at that point didn't sway the FAI from rejecting that flight for my badge attempt.
>
> My search at the time led me to the K2 (Lithium Iron Phosphate chemistry)batteries that were the subject of my spring of 2010 battery article in Soaring.
>
> Reaction to the article was mixed, and a partial retraction was printed the following month after an FAA DER (Designated Engineering Reviewer)with experience in certifying Lithium Ion batteries for some type of usage in commercial airliners, objected to the use of Lithium Iron Phosphate batteries in sailplanes because they hadn't been certified for that use by the FAA.
>
> It's now 2016, and I see a lot of K2 batteries in other sailplanes. Soaring supply companies in the U.S. seem to be providing K2 batteries or a similar battery from a different manufacturer on a regular basis. The K2 battery I purchased in 2009, and it's twin purchased a year later, are still providing power to my sailplane without incident. There seems to be no degradation in performance, and other than switching to Anderson Power Pole connectors, I have not made any changes to my battery set up.
>
> Has anyone out there had an issue with the usage of Lithium Iron Phosphate chemistry batteries in sailplanes?
>
> Just curious because, a lot of dire consequences were predicted after my article came out.
>
> SF
My experience with K2 Lithium Iron Phosphate batteries has been very positive.
They have worked perfectly for long flights for 3-4 years and they are still working well.
I did purchase the chargers that are sold by K2 which charge to a bit over 14V
I switched to a K2 Energy LiFePO4 battery and charger three years ago when I installed Flarm and updated my flight computer/variometer. I have had no problems whatsoever with either the battery or charger. It seems to have more real world life on a charge than the same sized SLA/AGM batteries I was using and as a bonus it's also lighter. I can only accommodate a single PS1270 size battery in my glider so it was nice to find that the K2 could handle demands of a six or seven hour flight with no problem even with the additional avionics I installed.
As for FAA certification (or EASA, Transport Canada etc.) the only battery I can think of with regulatory authority approval for aircraft use is the MERT PS1270 sized lithium-ion unit which claims to be JAR certified. I think it costs around 500 Euros. The batteries I've seen come with brand new gliders seem to be plain commercial-standard SLA/AGM units anyways.
On Tuesday, May 17, 2016 at 1:56:12 PM UTC-7, wrote:
> I switched to a K2 Energy LiFePO4 battery and charger three years ago when I installed Flarm and updated my flight computer/variometer. I have had no problems whatsoever with either the battery or charger. It seems to have more real world life on a charge than the same sized SLA/AGM batteries I was using and as a bonus it's also lighter. I can only accommodate a single PS1270 size battery in my glider so it was nice to find that the K2 could handle demands of a six or seven hour flight with no problem even with the additional avionics I installed.
>
> As for FAA certification (or EASA, Transport Canada etc.) the only battery I can think of with regulatory authority approval for aircraft use is the MERT PS1270 sized lithium-ion unit which claims to be JAR certified. I think it costs around 500 Euros. The batteries I've seen come with brand new gliders seem to be plain commercial-standard SLA/AGM units anyways.
Been using mine, with the K2 chargers, for over 3 years. No problems. I fly with 2 of them, some flights up to and over 8 hours, never come close to running out of juice between the two powering Flarm, radio, transponder, ClearNav flight computer and vario.
Got a K2 a couple seasons ago. Best battery I've ever used. Flew with it for 5 hours over two days without recharging. Ran the radio, two varios, a GPS and a Kobo eReader. Still showed 12.9 volts on the meter afterwards.
Richard[_9_]
May 18th 16, 01:26 AM
On Tuesday, May 17, 2016 at 5:11:36 PM UTC-7, WB wrote:
> Got a K2 a couple seasons ago. Best battery I've ever used. Flew with it for 5 hours over two days without recharging. Ran the radio, two varios, a GPS and a Kobo eReader. Still showed 12.9 volts on the meter afterwards.
I have been flying with the LiFeO batteries for 3 years. They are still delivering the amp hours advertised.
http://www.craggyaero.com/lifepo_battery.htm
Richard
www.craggyaero.com
On Tuesday, May 17, 2016 at 5:26:55 PM UTC-7, Richard wrote:
> On Tuesday, May 17, 2016 at 5:11:36 PM UTC-7, WB wrote:
> > Got a K2 a couple seasons ago. Best battery I've ever used. Flew with it for 5 hours over two days without recharging. Ran the radio, two varios, a GPS and a Kobo eReader. Still showed 12.9 volts on the meter afterwards.
>
> I have been flying with the LiFeO batteries for 3 years. They are still delivering the amp hours advertised.
>
> http://www.craggyaero.com/lifepo_battery.htm
>
> Richard
> www.craggyaero.com
Flying with a K2 since they first became available.
I have two batteries but have never had to switch to the backup.
Radio, transponder, 302, Oudie, Flarm.
No voltage drop from cold soak during wave flights.
Jonathan St. Cloud
May 18th 16, 06:36 AM
What are the differences between the K2 battery offered for $145 and the generic lifepo4 offered for $95, besides price?
joesimmers[_2_]
May 18th 16, 12:16 PM
Myself and several others I fly with have been using the STARK brand batteries sold by Ridge Soaring gliderport.
These batteries are excellent, no complaints from anyone after 2-3 seasons.
On Tuesday, May 17, 2016 at 12:58:47 PM UTC-4, SF wrote:
> During the winter of 2009 I was bored, and aggravated with the sealed lead acid batteries that I was using in my sailplane. They didn't hold the voltage above 12v for very long, they needed replacement every few years, and I had one die 5 miles away from the airport at the end of a 300K badge flight. My argument that I had 2,000 FT over final glide at that point didn't sway the FAI from rejecting that flight for my badge attempt.
>
> My search at the time led me to the K2 (Lithium Iron Phosphate chemistry)batteries that were the subject of my spring of 2010 battery article in Soaring.
>
> Reaction to the article was mixed, and a partial retraction was printed the following month after an FAA DER (Designated Engineering Reviewer)with experience in certifying Lithium Ion batteries for some type of usage in commercial airliners, objected to the use of Lithium Iron Phosphate batteries in sailplanes because they hadn't been certified for that use by the FAA.
>
> It's now 2016, and I see a lot of K2 batteries in other sailplanes. Soaring supply companies in the U.S. seem to be providing K2 batteries or a similar battery from a different manufacturer on a regular basis. The K2 battery I purchased in 2009, and it's twin purchased a year later, are still providing power to my sailplane without incident. There seems to be no degradation in performance, and other than switching to Anderson Power Pole connectors, I have not made any changes to my battery set up.
>
> Has anyone out there had an issue with the usage of Lithium Iron Phosphate chemistry batteries in sailplanes?
>
> Just curious because, a lot of dire consequences were predicted after my article came out.
>
> SF
I switched to the K2 batteries a year before Scott wrote the article since I was weight-challenged in my H301. These batteries held up very well with no sign of degradation at all.
I now fly a two-seater and have two of them in parallel to power all the essentials like a small fridge, espresso machine and a massage cushion and they still show 12V+ after a long flight!
Uli
jfitch
May 18th 16, 03:24 PM
On Tuesday, May 17, 2016 at 10:36:21 PM UTC-7, Jonathan St. Cloud wrote:
> What are the differences between the K2 battery offered for $145 and the generic lifepo4 offered for $95, besides price?
An appropriate battery contains a BMS that has overcharge and undercharge protection, and cell balancing. Some of the cheaper batteries do not have a BMS or have a less featured one.
I also use the Starkpower for instruments and a CTC for engine start, have had no problems in several years.
Richard[_9_]
May 18th 16, 04:09 PM
On Wednesday, May 18, 2016 at 7:24:20 AM UTC-7, jfitch wrote:
> On Tuesday, May 17, 2016 at 10:36:21 PM UTC-7, Jonathan St. Cloud wrote:
> > What are the differences between the K2 battery offered for $145 and the generic lifepo4 offered for $95, besides price?
>
> An appropriate battery contains a BMS that has overcharge and undercharge protection, and cell balancing. Some of the cheaper batteries do not have a BMS or have a less featured one.
>
> I also use the Starkpower for instruments and a CTC for engine start, have had no problems in several years.
And some less expensive ones do have the BMS with a more featured one.
Richard
www.craggyaero.com
jfitch
May 18th 16, 08:35 PM
On Wednesday, May 18, 2016 at 8:09:32 AM UTC-7, Richard wrote:
> On Wednesday, May 18, 2016 at 7:24:20 AM UTC-7, jfitch wrote:
> > On Tuesday, May 17, 2016 at 10:36:21 PM UTC-7, Jonathan St. Cloud wrote:
> > > What are the differences between the K2 battery offered for $145 and the generic lifepo4 offered for $95, besides price?
> >
> > An appropriate battery contains a BMS that has overcharge and undercharge protection, and cell balancing. Some of the cheaper batteries do not have a BMS or have a less featured one.
> >
> > I also use the Starkpower for instruments and a CTC for engine start, have had no problems in several years.
>
> And some less expensive ones do have the BMS with a more featured one.
>
> Richard
> www.craggyaero.com
Agreed - it's worth checking the battery you buy if it is an unknown brand.
Glad to hear the positive responses. As far as the questions regarding the K2's vs. less expensive batteries. I can't answer those questions except that small businessmen like soaring suppliers, operating in a small market, with small margins don't generally sell problem merchandise for very long. The alternate battery choices were not available to me when I was purchasing and evaluating.
The Lithium Iron Phosphate chemistry, gives you a lithium battery that will not supply it's own oxidizer in the case of a thermal event (fire), like the lithium ion batteries that are featured in laptop, hover board, and cell phone fire videos. Batteries that supply their own oxidizer are next to impossible to extinguish once they get going, so the battery chemistry choice is important.
That being said, these things contain a lot of energy. dump that out all at once, or treat them poorly, and bad things happen. So an internal battery management board (BMS) to prevent under and over charging is a really good idea. Most BMS boards also equalize the cells to improve charging and battery capacity. Some batteries can be purchased with and without them, so pay attention to what you are getting. The board should be internal so you can't look at a battery and see if it has a BMS board or not.
Buy a charger appropriate for your battery. Don't save money by attempting to re-purpose your old SLA battery charger.
The lithium Iron Phosphate batteries seem expensive unless you consider the life cycle cost. They are usually given a 2,000+ charge/discharge cycle lifetime. My limited experience with SLA batteries indicates that 200 cycles is about all they are good for.
Install an appropriately sized fuse (125% of the normal load is usually ok) as close to your battery terminals as possible. Then do a good job of protecting everything from the terminals to the fuse. My personal preference is to puddle hot melt glue over the terminals encasing them in a thick non conductive difficult to dislodge coating, and installing an automotive type blade fuse on the battery. Good insulated wire ( aircraft rated insulation, also a fire thing), and liberal use of heat shrink tubing can protect the rest. It's not pretty after I finish with it, but its not going to short out either.
I switched to Anderson PowerPole connectors after hearing the HAM radio guys rave about them. After you buy the crimper and watch a online video on how to use it, they are pretty slick connectors. I put hot melt glue in the open end of them to stress relieve the internal crimp connector when someone pulls on the wire instead of the connector.
12V isn't a lot to begin with, Use a wire at least one size larger than you think you need. The only penalty for larger wire is it's increased weight and size which is not usually much of a factor for the typical glider installation. Unless you don't put a fuse near you battery, in that case, your plan is to use the wire as a fuse, so use a small wire size in that instance.
If you don't know what you are doing around this kind of stuff, then get someone else that does to help. These things contain a lot of energy and they can dump it out in a hurry, so be careful. One of my electronic techs shorted out a lithium battery, and we had to evacuate a 200,000 Sq Ft manufacturing facility. No fire, but an impressive amount of foul smelling smoke. The firemen were impressed.
SF
Brian[_1_]
May 19th 16, 03:05 AM
Would like to go to a K2 style battery, but have a 10 watt solar panel on the glider. I have yet to get a good answer on how to connect the solar panel to the battery. The BMS would probably prevent overcharging, but haven't got anything that says this is acceptable or what kind or charge controller would work with significantly reducing the charging capability.
Any Ideas?
Brian
Tom Kelley #711
May 19th 16, 03:41 AM
On Wednesday, May 18, 2016 at 8:05:57 PM UTC-6, Brian wrote:
> Would like to go to a K2 style battery, but have a 10 watt solar panel on the glider. I have yet to get a good answer on how to connect the solar panel to the battery. The BMS would probably prevent overcharging, but haven't got anything that says this is acceptable or what kind or charge controller would work with significantly reducing the charging capability.
>
> Any Ideas?
>
> Brian
Bioenno Power 12V/24V, 10A Solar Charge Controller for LiFePO4 Batteries (SC-122410T)
Availability: In stock
$39.99
Bioenno Power 12V/24V, 10A Solar Charge Controller (Model SC-122410T) is a versatile controller for solar systems, that can charge LiFePO4 (Lithium Iron Phosphate) batteries! This solar controller accepts either 12V/24V input from solar panels and can handle up to 10 Amps. The solar controller provides a regulated voltage output for charging 12V or 24V LiFePO4 batteries. The solar controller also provides a regulated 12V or 24V output for electrical loads (depending on whether a 12V or 24V battery is used). Solar controllers are required for all solar systems in order to maintain a regulated output voltage to charge batteries and for maintaining a regulating output voltage for loads.
Best. #711.
Richard[_9_]
May 19th 16, 03:41 AM
On Wednesday, May 18, 2016 at 7:05:57 PM UTC-7, Brian wrote:
> Would like to go to a K2 style battery, but have a 10 watt solar panel on the glider. I have yet to get a good answer on how to connect the solar panel to the battery. The BMS would probably prevent overcharging, but haven't got anything that says this is acceptable or what kind or charge controller would work with significantly reducing the charging capability.
>
> Any Ideas?
>
> Brian
https://www.bioennopower.com/pages/overview-of-solar-products
Richard
www.craggyaero.com
On Wednesday, May 18, 2016 at 5:49:09 PM UTC-7, SF wrote:
> Glad to hear the positive responses. As far as the questions regarding the K2's vs. less expensive batteries. I can't answer those questions except that small businessmen like soaring suppliers, operating in a small market, with small margins don't generally sell problem merchandise for very long. The alternate battery choices were not available to me when I was purchasing and evaluating.
>
> The Lithium Iron Phosphate chemistry, gives you a lithium battery that will not supply it's own oxidizer in the case of a thermal event (fire), like the lithium ion batteries that are featured in laptop, hover board, and cell phone fire videos. Batteries that supply their own oxidizer are next to impossible to extinguish once they get going, so the battery chemistry choice is important.
>
> That being said, these things contain a lot of energy. dump that out all at once, or treat them poorly, and bad things happen. So an internal battery management board (BMS) to prevent under and over charging is a really good idea. Most BMS boards also equalize the cells to improve charging and battery capacity. Some batteries can be purchased with and without them, so pay attention to what you are getting. The board should be internal so you can't look at a battery and see if it has a BMS board or not.
>
> Buy a charger appropriate for your battery. Don't save money by attempting to re-purpose your old SLA battery charger.
>
> The lithium Iron Phosphate batteries seem expensive unless you consider the life cycle cost. They are usually given a 2,000+ charge/discharge cycle lifetime. My limited experience with SLA batteries indicates that 200 cycles is about all they are good for.
>
> Install an appropriately sized fuse (125% of the normal load is usually ok) as close to your battery terminals as possible. Then do a good job of protecting everything from the terminals to the fuse. My personal preference is to puddle hot melt glue over the terminals encasing them in a thick non conductive difficult to dislodge coating, and installing an automotive type blade fuse on the battery. Good insulated wire ( aircraft rated insulation, also a fire thing), and liberal use of heat shrink tubing can protect the rest. It's not pretty after I finish with it, but its not going to short out either.
>
> I switched to Anderson PowerPole connectors after hearing the HAM radio guys rave about them. After you buy the crimper and watch a online video on how to use it, they are pretty slick connectors. I put hot melt glue in the open end of them to stress relieve the internal crimp connector when someone pulls on the wire instead of the connector.
>
> 12V isn't a lot to begin with, Use a wire at least one size larger than you think you need. The only penalty for larger wire is it's increased weight and size which is not usually much of a factor for the typical glider installation. Unless you don't put a fuse near you battery, in that case, your plan is to use the wire as a fuse, so use a small wire size in that instance.
>
> If you don't know what you are doing around this kind of stuff, then get someone else that does to help. These things contain a lot of energy and they can dump it out in a hurry, so be careful. One of my electronic techs shorted out a lithium battery, and we had to evacuate a 200,000 Sq Ft manufacturing facility. No fire, but an impressive amount of foul smelling smoke. The firemen were impressed.
>
> SF
I took the easy (but more expensive) way out by buying the Walter Dittel battery box and mounting plate when I upgraded my battery mount. When I got the glider it had a box that only came halfway up the sides of the battery, the connectors were simple spade lugs which had to be slid on to the batter terminals and there was a simple strap over the top to hold it in. There was also no fuse or breaker at the battery itself. The Dittel box can only hold a PS1270 size battery but if that's the size you're going to use it's pretty damn good overall. The DIN connector (The Germans love those things don't they?) is kind of Mickey Mouse but aside from that I can't think of anything that would improve it. Someone years ago in my club came up with the idea of gluing a plastic project box over top of the terminals of the club batteries which both protects the terminals and provides a mounting point for the connector socket and fuse or breaker. They also used 3 pin XLR connectors - unconventional but I have to say that they seem to work perfectly. Power Poles are fantastic connectors too.
Brian[_1_]
May 19th 16, 05:48 PM
>
> https://www.bioennopower.com/pages/overview-of-solar-products
>
> Richard
> www.craggyaero.com
Thanks Richard, I have looked at these before but a 10amp controller seems a bit large for my 600ma panel. A 1amp controller would seem more appropriate.
This one may work just fine, but I can't find any data on power loss or efficiency of the controller. If it draws 200ma, that is a 30% loss for my small solar panel.
Brian
Dave Springford
May 20th 16, 01:01 AM
I have been using the factory installed Strobel solar system on my 29 with K2 batteries for the past 4 years without issue. The Strobel controller was designed for Lead-acid chemistry and the K2's "can" be charged by lead-acid chargers due to their lower output voltage. That being said, the 13,75 Volt output of lead-acid systems won't charge the LiFePo to it's full capacity that needs 14.6 V.
krasw
May 20th 16, 09:50 AM
On Wednesday, 18 May 2016 22:35:08 UTC+3, jfitch wrote:
>
> Agreed - it's worth checking the battery you buy if it is an unknown brand.
I bought one of these "brand" batteries from Aeroakku.com (german shop specializing aviation batteries). It died after one year use because BMS electronics self-destructed, non repairable. The shop promptly informed me that their warranty is SIX MONTHS. After some heated emails they were kind enough to not send me bill for checking what went wrong with the faulty battery (yes they tried to do that at first), and offered me a whopping 10% discount on next battery. After that I learned that Aeroakku battery came from no-name-factory in China, as I quess most of LiFePos, with Aeroakku-sticker on top of it. Recently I bought another no-name Lifepo from another webshop who offers industry standard 2 year warranty for their products, for roughly half the price.
Benedict Smith
May 20th 16, 07:06 PM
At 00:01 20 May 2016, Dave Springford wrote:
>I have been using the factory installed Strobel solar system on my 29
with
>=
>K2 batteries for the past 4 years without issue. The Strobel controller
>wa=
>s designed for Lead-acid chemistry and the K2's "can" be charged by
>lead-ac=
>id chargers due to their lower output voltage. That being said, the
13,75
>=
>Volt output of lead-acid systems won't charge the LiFePo to it's full
>capac=
>ity that needs 14.6 V.
>
David,
Find yourself a good electronics hobbyist who understands charging
circuits,
it should be a simple job to tweak the regulator voltage so it fully
charges
your LiFe battery, (provided the circuitry is not encapsulated or potted)
however if you do this then CLEARLY mark it as modified because it will
potentially kill SLA batteries after a short time, if you were in the UK I
would
offer to look at this for you, however posting it to and from the US is
impractical.
Ben.
jfitch
May 20th 16, 09:39 PM
On Friday, May 20, 2016 at 11:15:08 AM UTC-7, Benedict Smith wrote:
> At 00:01 20 May 2016, Dave Springford wrote:
> >I have been using the factory installed Strobel solar system on my 29
> with
> >=
> >K2 batteries for the past 4 years without issue. The Strobel controller
> >wa=
> >s designed for Lead-acid chemistry and the K2's "can" be charged by
> >lead-ac=
> >id chargers due to their lower output voltage. That being said, the
> 13,75
> >=
> >Volt output of lead-acid systems won't charge the LiFePo to it's full
> >capac=
> >ity that needs 14.6 V.
> >
>
> David,
> Find yourself a good electronics hobbyist who understands charging
> circuits,
> it should be a simple job to tweak the regulator voltage so it fully
> charges
> your LiFe battery, (provided the circuitry is not encapsulated or potted)
> however if you do this then CLEARLY mark it as modified because it will
> potentially kill SLA batteries after a short time, if you were in the UK I
> would
> offer to look at this for you, however posting it to and from the US is
> impractical.
> Ben.
14.0V will be sufficient to fully charge a LiFePO4 battery. 14.6 will do it faster, but is a little harder on them. 13.8 won't get them to fully charged. Yes, I know what the specs say from the retailers, but I have also seen the test results. You do not what to "float" charge a LiFePo4 battery, but if you are using an SLA charger that floats at 13.6 or 13.8 it won't harm them, because charging will be effectively terminated at float voltage.
Has anyone else tried the Shorai LiFeP motorcycle starter batteries. I put a 36 aH one in my Goldwing and was so blown away with it I bought an 18 aH for my Ventus. It is still amazing after three years. Buy the charger with it and forget about electronics shops. Ok it is not the perfect form & fit of the old gel cells, but it fits in the double slot where I used to have two gel cells and easily outperforms both of them by a lot. It is great having better than 13 volts with an SN-10 all day long. I use a 2nd 14aH to run my transponder which lasts for days. Not cheap, but cost is nothing compared to the years of headaches with gel cells.
jfitch
May 21st 16, 06:02 AM
On Friday, May 20, 2016 at 3:34:11 PM UTC-7, wrote:
> Has anyone else tried the Shorai LiFeP motorcycle starter batteries. I put a 36 aH one in my Goldwing and was so blown away with it I bought an 18 aH for my Ventus. It is still amazing after three years. Buy the charger with it and forget about electronics shops. Ok it is not the perfect form & fit of the old gel cells, but it fits in the double slot where I used to have two gel cells and easily outperforms both of them by a lot. It is great having better than 13 volts with an SN-10 all day long. I use a 2nd 14aH to run my transponder which lasts for days. Not cheap, but cost is nothing compared to the years of headaches with gel cells.
I would not recommend the Shorai starter batteries for instrument power. These are an example of the "lead acid equivalent AH" that have become popular in the Lithium business. In an engine start application, the AH requirement is quite small, what you need is a very high current for a very short time. Taking advantage of this and the high current capability of very small lithium cells, suppliers like Shorai are building batteries with the high current required, but very low capacity to save money. It works fine for starting your motorcycle, but does not have the same capacity if low current for long time periods are the application. Shorai themselves explain "PBeq AHr" here:
http://shoraipower.com/faq
For instruments, you want real AH capacity, not "equivalent". One tipoff when you are looking at specs is the weight: a LiFePO4 battery will weigh about half of what an SLA weighs in the same real capacity. If it is less than that, either it isn't really the same capacity, or they have made a major technological breakthrough. Nothing wrong with Shorai for what they were made for, but for a glider you are better off with a K2 or Starkpower or similar.
Dave Springford
May 22nd 16, 11:46 PM
thanks Ben,
I've thought of that too, but I don't know if the Stobl has an adjustable voltage regulator or if everything is all sealed up. I need to look under the panel. In the meantime, it keeps the batteries going for longer than I can fly in a day!
On Friday, May 20, 2016 at 4:39:37 PM UTC-4, jfitch wrote:
> On Friday, May 20, 2016 at 11:15:08 AM UTC-7, Benedict Smith wrote:
> > At 00:01 20 May 2016, Dave Springford wrote:
> > >I have been using the factory installed Strobel solar system on my 29
> > with
> > >=
> > >K2 batteries for the past 4 years without issue. The Strobel controller
> > >wa=
> > >s designed for Lead-acid chemistry and the K2's "can" be charged by
> > >lead-ac=
> > >id chargers due to their lower output voltage. That being said, the
> > 13,75
> > >=
> > >Volt output of lead-acid systems won't charge the LiFePo to it's full
> > >capac=
> > >ity that needs 14.6 V.
> > >
> >
> > David,
> > Find yourself a good electronics hobbyist who understands charging
> > circuits,
> > it should be a simple job to tweak the regulator voltage so it fully
> > charges
> > your LiFe battery, (provided the circuitry is not encapsulated or potted)
> > however if you do this then CLEARLY mark it as modified because it will
> > potentially kill SLA batteries after a short time, if you were in the UK I
> > would
> > offer to look at this for you, however posting it to and from the US is
> > impractical.
> > Ben.
>
> 14.0V will be sufficient to fully charge a LiFePO4 battery. 14.6 will do it faster, but is a little harder on them. 13.8 won't get them to fully charged. Yes, I know what the specs say from the retailers, but I have also seen the test results. You do not what to "float" charge a LiFePo4 battery, but if you are using an SLA charger that floats at 13.6 or 13.8 it won't harm them, because charging will be effectively terminated at float voltage.
Combining my experience and most everything I've read, LiFePO4 chemistry is not meant to be trickle charged as typical solar panel/charger would provide. LiFePO4 extended life cycles (some claim 2000 or more) depend on deep discharges (like 70% to 80% of capacity) then being fully recharged. If you want to depend on solar charging perhaps it would be better to stay with battery chemistry which likes trickle charging (such as SLA or AGM). FWIW...down the road my guess there will be purpose built LiFePO4 solar chargers which do not initiate charging until the LiFePO4 battery has used 70%-80% of its capacity.
bumper[_4_]
May 23rd 16, 07:51 AM
On Sunday, May 22, 2016 at 6:49:11 PM UTC-7, wrote:
> Combining my experience and most everything I've read, LiFePO4 chemistry is not meant to be trickle charged as typical solar panel/charger would provide. LiFePO4 extended life cycles (some claim 2000 or more) depend on deep discharges (like 70% to 80% of capacity) then being fully recharged. If you want to depend on solar charging perhaps it would be better to stay with battery chemistry which likes trickle charging (such as SLA or AGM). FWIW....down the road my guess there will be purpose built LiFePO4 solar chargers which do not initiate charging until the LiFePO4 battery has used 70%-80% of its capacity."
LiFePO4 batteries don't need to be deeply discharged and are "happy" with even light discharge charge cycles. And while it's true, it's preferable to store these batteries at a lower voltage that fully charged (for longest life), that's not always practical (though some chargers have a setting to maintain them at the lower storage voltage (the Shorai I installed in my Honda S2000 has a charger that does that). In any case, you can swap out the solar charge controller in your glider for one that's designed for LFP batteries like this one: http://www.amazon.com/Bioenno-Power-Controller-Batteries-SC-122410T/dp/B016LEYAHC/ref=sr_1_4?ie=UTF8&qid=1463985871&sr=8-4&keywords=solar+charge+controller+lifepo4
Some thoughts:
Re: life of batteries: Number of cycles is not an issue for most. How many times do you fly in a year? Even if 50 times (I wish!) it would take 4 years to use up the 200 cycles life of a lead-acid battery, and by then it would deteriorate anyway due to time alone. Even the Lithium battery is going to die after a decade or so, thus will never even get close to the promised 2000 cycles.
Re: capacity: in my case, I find that a small 4 or 5 AH battery suffices, even for a 6-hour flight. OK, I don't have FLARM nor a transponder. And my computer is a Nook e-reader, drawing about 1/4 amp. YMMV.
Re: cost: I considered a LiFePo battery last year when I needed to replace my SLA battery (again), but found that they are still about $150, and I got _three_ new small (4 or 5 AH) SLAs for a total of $27 including the shipping (from Apex). The weight of such is similar to the weight of a (larger) LiFePo battery, and for my needs, the capacity is sufficient (see above). A larger SLA is not expensive either, but does add a few pounds.
Re: solar panel in glider: don't think of it as a charger for the battery. Rather, is helps supply the ongoing current to the always-on (while flying) gizmos, reducing the load on the battery (possibly to zero when you are not talking on the radio). You do need something that will prevent overcharge if the glider sits in the sun a while, but a charge controller designed for SLA is fine for that. Worry about fully recharging the battery only when you take it home. (Unless you want to avoid having to take it home.)
A 10-watt solar panel is fairly large, presumably it's the flexible type, glued onto the outside of the glider? I've considered adding a smaller panel inside the cockpit, presumably on the glare shield above the instruments, but doing the math convinced me that it's not worth the trouble, as it would only stretch the battery capacity a modest amount. It's easier to just get a larger battery. (Also, a panel on the glare shield may reflect sunshine into the pilot's eyes, directly, or reflected again via the canopy.)
John Smith
June 3rd 16, 10:21 PM
On Wednesday, May 18, 2016 at 7:05:57 PM UTC-7, Brian wrote:
> Would like to go to a K2 style battery, but have a 10 watt solar panel on the glider. I have yet to get a good answer on how to connect the solar panel to the battery. The BMS would probably prevent overcharging, but haven't got anything that says this is acceptable or what kind or charge controller would work with significantly reducing the charging capability.
>
> Any Ideas?
>
> Brian
Brian,
A 10w solar panel isn't much information. What are the Voltage and Amps?
You probably don't even need a charge controller if your attempting to fly with your Solar Panel hooked up to the battery. Your draw from equipment will be greater than the panels ability to charge it.
Find out what the charging voltage of the battery is and make sure you have something inline to keep the voltage going to the battery at that or less.
10w won't keep up with demand but should help extend the life while flying.
I'm not an electrical expert so take everything above with a grain of salt.
I did start a Lawn Care company using all electric equipment and solar panels on the trailer to keep them topped up.
John
Brian[_1_]
June 4th 16, 02:41 AM
It typically runs about 500ma, about 12.8 volts depending on battery (lead acid ) status.
In flight it definitely not and issue, demand is about 750ma.
However on the ground between flights is the concern where there is no demand. That is the big advantage of the solar panel, as it can top off the battery for the next flight, I rarely have to remove the battery.
I only run the panel on the ground when flying almost daily, otherwise the airplane is in a trailer.
I don't run any controller with the lead acid batteries as it takes a couple days of not flying to get the voltage up over about 14 volts.
Brian
Vaughn Simon[_2_]
June 4th 16, 03:50 PM
On 5/19/2016 12:48 PM, Brian wrote:
> Thanks Richard, I have looked at these before but a 10amp controller seems
>a bit large for my 600ma panel. A 1amp controller would seem more
appropriate.
> This one may work just fine, but I can't find any data on power loss or
>efficiency of the controller. If it draws 200ma, that is a 30% loss for my small solar panel.
Your 200 MA guess might be very high! The 12-amp controller for my
little home solar system (Xantrex C-12) draws only 7 MA when charging
and 3 MA at night. That is data that should be included in any solar
controller specification sheet.
Actually, if your controller drew 200 MA 24/7, then your solar system
could be a net loss with that panel, because on a daily basis you are
lucky to get more than a few hours of equivalent full-sun power from any
solar panel. Also note that a solar panel only delivers its rated
output under a very specific set of conditions. If all of those
conditions don't simultaneously exist (which is almost always) then you
get less. Probably much less!
Still, charging lead acid batteries without a controller (as you state
later in the thread) is a chancy proposition. I've seen lots of
perfectly good lead acid batteries ruined by overcharging.
noel.wade
June 4th 16, 07:26 PM
This thread is why people think soaring is all just cranky old farts.
For those of you that don't like tracking or electronics in the cockpit or the ground: What does it matter if someone else carries that gear? If they aren't actively flying reckless in your airspace, their preferences don't affect you AT ALL. Being bitchy about it is just as productive as whining about bandwagon sports fans.
The man had a question and was looking for info or help. How does being a dick about it help ANYONE? If you don't have something to add to the conversation, quit complaining on the Internet and go fly, or work on your glider, or do something productive.
No one cares about your negative opinion, and posting it for the world to see serves absolutely no purpose, other than to make you look like an asshole, tearing someone down for no reason (when they're trying to carry more safety gear, no less - Who criticizes safety)!?
The world doesn't need more assholes, so just don't do it.
--Noel
Andy Blackburn[_3_]
June 4th 16, 07:31 PM
On Tuesday, May 17, 2016 at 9:58:47 AM UTC-7, SF wrote:
> During the winter of 2009 I was bored, and aggravated with the sealed lead acid batteries that I was using in my sailplane. They didn't hold the voltage above 12v for very long, they needed replacement every few years, and I had one die 5 miles away from the airport at the end of a 300K badge flight. My argument that I had 2,000 FT over final glide at that point didn't sway the FAI from rejecting that flight for my badge attempt.
>
> My search at the time led me to the K2 (Lithium Iron Phosphate chemistry)batteries that were the subject of my spring of 2010 battery article in Soaring.
>
> Reaction to the article was mixed, and a partial retraction was printed the following month after an FAA DER (Designated Engineering Reviewer)with experience in certifying Lithium Ion batteries for some type of usage in commercial airliners, objected to the use of Lithium Iron Phosphate batteries in sailplanes because they hadn't been certified for that use by the FAA.
>
> It's now 2016, and I see a lot of K2 batteries in other sailplanes. Soaring supply companies in the U.S. seem to be providing K2 batteries or a similar battery from a different manufacturer on a regular basis. The K2 battery I purchased in 2009, and it's twin purchased a year later, are still providing power to my sailplane without incident. There seems to be no degradation in performance, and other than switching to Anderson Power Pole connectors, I have not made any changes to my battery set up.
>
> Has anyone out there had an issue with the usage of Lithium Iron Phosphate chemistry batteries in sailplanes?
>
> Just curious because, a lot of dire consequences were predicted after my article came out.
>
> SF
Here is a link to a comparison I ran three years ago for new K2 9.8Ah LiFePO4 batteries versus Powersonic 10.5Ah SLA batteries (these are the ones that are slightly taller). I used a programmable battery tester that permitted me to simulate normal base load plus occasional radio transmissions. My caseload in around an amp IIRC.
You can see the K2 batteries have a flatter and longer discharge profile. I repeated the test after three years of use for the K2 batteries. I didn't notice any significant degradation in capacity. Note that the flat profile means both that normal "capacity remaining" indications on your soaring instruments will not be accurate (at all - even if you have an option for LiFePO4 the flat voltage profile makes it challenging to estimate). Also, if you set a voltage threshold for a low battery warning it normally indicates that you have perhaps 10-15 minutes left because of the steep falloff, so you need either to be more vigilant or slave two batteries together (I use diodes to separate the batteries - just in case). For most people who don't have panels that draw an amp or more, don't talk incessantly on the radio and/or don't to 8-hour flights, capacity ought not be a problem.
https://drive.google.com/drive/folders/0Bw1ChKkWEYLNMU9Mem5QcTBMQnM
9B
Vaughn Simon[_2_]
June 4th 16, 08:18 PM
On 6/4/2016 2:26 PM, noel.wade wrote:
> The world doesn't need more assholes, so just don't do it
Ummm, were you responding to something I wrote?
Vaughn
Brian[_1_]
June 5th 16, 04:48 AM
That is simply my point about the controller Richard recommended, I just don't know what the efficiency of it is.
7ma loss would be excellent.
The controller is inexpensive enough I may order one and measure the efficiency.
Flying everyday, my panel doesn't usually fully recharge the battery in between flights, If I don't fly for a day to two I will disconnect the panel as I agree it would be easy to overcharge the Lead Acid batteries. That is one of my concerns about going to a LIPO4 battery, with the flat charge/discharge curve it may be harder to tell when it is getting close to fully charged, compared to Lead Acid battery.
Brian
Dan Marotta
June 5th 16, 02:43 PM
The LiFePO4 battery that I used had a built-in battery management system
(BMS) which balanced the cells and it came with a "smart" charger
designed specifically for that battery (according to there
specifications). Though, according to the spec sheet, I could leave it
plugged in continuously, I set it on a lamp timer and charged it a
couple of hours per day when parked in the hangar. On safari, I removed
the batteries and charged them in the motel.
To use a solar panel I'd get a charge controller designed especially for
lithium batteries.
On 6/4/2016 9:48 PM, Brian wrote:
> That is simply my point about the controller Richard recommended, I just don't know what the efficiency of it is.
> 7ma loss would be excellent.
>
> The controller is inexpensive enough I may order one and measure the efficiency.
>
> Flying everyday, my panel doesn't usually fully recharge the battery in between flights, If I don't fly for a day to two I will disconnect the panel as I agree it would be easy to overcharge the Lead Acid batteries. That is one of my concerns about going to a LIPO4 battery, with the flat charge/discharge curve it may be harder to tell when it is getting close to fully charged, compared to Lead Acid battery.
>
> Brian
--
Dan, 5J
December 2nd 16, 02:43 AM
On Wednesday, May 18, 2016 at 4:58:47 AM UTC+12, SF wrote:
> During the winter of 2009 I was bored, and aggravated with the sealed lead acid batteries that I was using in my sailplane. They didn't hold the voltage above 12v for very long, they needed replacement every few years, and I had one die 5 miles away from the airport at the end of a 300K badge flight. My argument that I had 2,000 FT over final glide at that point didn't sway the FAI from rejecting that flight for my badge attempt.
>
> My search at the time led me to the K2 (Lithium Iron Phosphate chemistry)batteries that were the subject of my spring of 2010 battery article in Soaring.
>
> Reaction to the article was mixed, and a partial retraction was printed the following month after an FAA DER (Designated Engineering Reviewer)with experience in certifying Lithium Ion batteries for some type of usage in commercial airliners, objected to the use of Lithium Iron Phosphate batteries in sailplanes because they hadn't been certified for that use by the FAA.
>
> It's now 2016, and I see a lot of K2 batteries in other sailplanes. Soaring supply companies in the U.S. seem to be providing K2 batteries or a similar battery from a different manufacturer on a regular basis. The K2 battery I purchased in 2009, and it's twin purchased a year later, are still providing power to my sailplane without incident. There seems to be no degradation in performance, and other than switching to Anderson Power Pole connectors, I have not made any changes to my battery set up.
>
> Has anyone out there had an issue with the usage of Lithium Iron Phosphate chemistry batteries in sailplanes?
>
> Just curious because, a lot of dire consequences were predicted after my article came out.
>
> SF
I'm flying with the 19amphr Shorai LFX 19 battery - rated capacity is closer to 6 or 7 amp-hr but very lightweight and the avionics love the 13.8 volt nominal output. Very happy with is on 5-6 hr flights, running LX Nano3, S80, Transponder Mode A & C, radio and 8" mounted Galaxy tablet. Nil problems except of the regulatory type - I understand various manufacturers are specifying LiFePO4 batteries now so I imagine the Aviation Authorities will ahve to deal with this issue at some time. Currently looking to double up this battery for true 10hr plus potential although a 20amp-hr would be ideal from another manufacturer. Look for some kind of UN spec - I think it is UN38.2 specification.
Cheers,
Andy
New Zealand
bumper[_4_]
December 2nd 16, 05:45 AM
This one: 19.8 AH, same size at the 18 to 19 AH lead acid used in Schleicher ASH26E. You will need to get the charger from them too.
http://www.batterypete.com/batteries/ctc-12-8v-19-8ah-253-44wh-lithium-battery-lfp128198/
bumper
bumper[_4_]
December 2nd 16, 06:01 AM
On Thursday, December 1, 2016 at 6:43:11 PM UTC-8, wrote:
> On Wednesday, May 18, 2016 at 4:58:47 AM UTC+12, SF wrote:
> > During the winter of 2009 I was bored, and aggravated with the sealed lead acid batteries that I was using in my sailplane. They didn't hold the voltage above 12v for very long, they needed replacement every few years, and I had one die 5 miles away from the airport at the end of a 300K badge flight. My argument that I had 2,000 FT over final glide at that point didn't sway the FAI from rejecting that flight for my badge attempt.
> >
> > My search at the time led me to the K2 (Lithium Iron Phosphate chemistry)batteries that were the subject of my spring of 2010 battery article in Soaring.
> >
> > Reaction to the article was mixed, and a partial retraction was printed the following month after an FAA DER (Designated Engineering Reviewer)with experience in certifying Lithium Ion batteries for some type of usage in commercial airliners, objected to the use of Lithium Iron Phosphate batteries in sailplanes because they hadn't been certified for that use by the FAA.
> >
> > It's now 2016, and I see a lot of K2 batteries in other sailplanes. Soaring supply companies in the U.S. seem to be providing K2 batteries or a similar battery from a different manufacturer on a regular basis. The K2 battery I purchased in 2009, and it's twin purchased a year later, are still providing power to my sailplane without incident. There seems to be no degradation in performance, and other than switching to Anderson Power Pole connectors, I have not made any changes to my battery set up.
> >
> > Has anyone out there had an issue with the usage of Lithium Iron Phosphate chemistry batteries in sailplanes?
> >
> > Just curious because, a lot of dire consequences were predicted after my article came out.
> >
> > SF
>
> I'm flying with the 19amphr Shorai LFX 19 battery - rated capacity is closer to 6 or 7 amp-hr but very lightweight and the avionics love the 13.8 volt nominal output. Very happy with is on 5-6 hr flights, running LX Nano3, S80, Transponder Mode A & C, radio and 8" mounted Galaxy tablet. Nil problems except of the regulatory type - I understand various manufacturers are specifying LiFePO4 batteries now so I imagine the Aviation Authorities will ahve to deal with this issue at some time. Currently looking to double up this battery for true 10hr plus potential although a 20amp-hr would be ideal from another manufacturer. Look for some kind of UN spec - I think it is UN38.2 specification.
>
> Cheers,
> Andy
> New Zealand
Shorai uses a sort of lead acid "starting battery" AH equivalent rating as their batteries are intended for motorsports and are popular for use in motorcycles. The cell spacing is optimized for high current for short periods. Other LiFePO4's are made that are optimized for storage and have a more moderate current demand capability - often limited by an on-board BMS (battery management system), and the AH rating on this type would be more in keeping to the Pb batteries traditionally used in gliders. With a a few additional advantages, more cycles, lighter weight/higher power density, and voltage doesn't drop off during discharge (until the end!) etc. Some, like the CTC brand I posted earlier, have a storage AH rating and can also deliver enough current for short periods to be used for the starter on the Wankel engine on my ASH26E.
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