A Simple Question About LiFePO4 Batteries

On Friday, May 11, 2018 at 1:37:03 PM UTC-6, wrote:
Not to start another chapter in "Battery Wars" but I have a simple question about "drop in" LiFePO4 battery replacements for SLA batteries in gliders.

For years, I've used an SLA battery with the same footprint as the common glider size of 7Ah to 9Ah--i.e., 5.95" x 2.56"--except a little taller--i.e., 4.61" high vs. 3.86" (specs are from the PowerSonic line but other brands are similar). It's an easy swap in my ASW 24, only requiring a different hold-down strap. There's about 20% more internal volume, which seems to equate to at least 20% more claimed capacity. I've used enough of these that I know they do perform longer than the conventional-size SLA batteries most pilots use.

However, I can't find a LiFePO4 equivalent for it. Does such a thing exist? All I've seen discussed here or available online seem to be the "traditional" size. I've been told that this is because there's already excess space inside the enclosure, that it's not packed to the gills with mat/chemicals as SLAs are, and that the extra 3/4" wouldn't allow adding additional cells. And besides, I don't need it anyway (I'm running PowerFLARM, radio, CNv vario, and PNA; no transponder yet).

Then I see that some LiFePO4 batteries are rated slightly higher for the same enclosure size. Even the K2 battery touted in adverts as "10 Ah" seems to be 9.6 Ah in the specs. And that's ignoring loads, discharge rates, temperatures, etc.

Given the price differential and the necessity for a new charger (although not according to the K2 site), and especially in light of the recent stories of LiFePO4 batteries crapping out long before their promised lifespans, maybe I should just continue to buy a new SLA battery every year or two and wait for this fad to pass.

As I said, a simple question.

Chip Bearden

I use these on my 29(sorry Richard), slides right in and my battery compartments are the same size as a 27.

https://www.bioennopower.com/collect...d-green-case-1

Not sure about your 24 size battery compartment. When measured are 5.95Lx2..96Wx3.66H. Last flight went over 6 hrs on one. My 10 amps are the same size and what I was using, I use about 1.32 amps per hour as I don't use the radio very much. Do have a Sandia transponder. When recharged it showed it had used 6.929 amps.
Used SLA's, now after using these would not go back. Have had no problems with them and 2 are now going on more than several years old and have well over 200 recharge cycles on them. I recharge them with my RC charger which I can set the charge rate. Been recharging them at 5 amps since new.

Ya, it's kinda late to your post, but may help someone else.

Best. Tom #711.

On Friday, May 18, 2018 at 10:16:07 AM UTC-7, Tom Kelley #711 wrote:
On Friday, May 11, 2018 at 1:37:03 PM UTC-6, wrote:
Not to start another chapter in "Battery Wars" but I have a simple question about "drop in" LiFePO4 battery replacements for SLA batteries in gliders.

For years, I've used an SLA battery with the same footprint as the common glider size of 7Ah to 9Ah--i.e., 5.95" x 2.56"--except a little taller--i.e., 4.61" high vs. 3.86" (specs are from the PowerSonic line but other brands are similar). It's an easy swap in my ASW 24, only requiring a different hold-down strap. There's about 20% more internal volume, which seems to equate to at least 20% more claimed capacity. I've used enough of these that I know they do perform longer than the conventional-size SLA batteries most pilots use.

However, I can't find a LiFePO4 equivalent for it. Does such a thing exist? All I've seen discussed here or available online seem to be the "traditional" size. I've been told that this is because there's already excess space inside the enclosure, that it's not packed to the gills with mat/chemicals as SLAs are, and that the extra 3/4" wouldn't allow adding additional cells. And besides, I don't need it anyway (I'm running PowerFLARM, radio, CNv vario, and PNA; no transponder yet).

Then I see that some LiFePO4 batteries are rated slightly higher for the same enclosure size. Even the K2 battery touted in adverts as "10 Ah" seems to be 9.6 Ah in the specs. And that's ignoring loads, discharge rates, temperatures, etc.

Given the price differential and the necessity for a new charger (although not according to the K2 site), and especially in light of the recent stories of LiFePO4 batteries crapping out long before their promised lifespans, maybe I should just continue to buy a new SLA battery every year or two and wait for this fad to pass.

As I said, a simple question.

Chip Bearden

I use these on my 29(sorry Richard), slides right in and my battery compartments are the same size as a 27.

https://www.bioennopower.com/collect...d-green-case-1

Not sure about your 24 size battery compartment. When measured are 5.95Lx2.96Wx3.66H. Last flight went over 6 hrs on one. My 10 amps are the same size and what I was using, I use about 1.32 amps per hour as I don't use the radio very much. Do have a Sandia transponder. When recharged it showed it had used 6.929 amps.
Used SLA's, now after using these would not go back. Have had no problems with them and 2 are now going on more than several years old and have well over 200 recharge cycles on them. I recharge them with my RC charger which I can set the charge rate. Been recharging them at 5 amps since new.

Ya, it's kinda late to your post, but may help someone else.

Best. Tom #711.

Tom,

I used to sell Bioenno until I got an entire bad batch of Batteries.

Less than 5 AH for a 9Ah Battery.

Richard
www.craggyaero.com

On Friday, May 18, 2018 at 10:16:07 AM UTC-7, Tom Kelley #711 wrote:
On Friday, May 11, 2018 at 1:37:03 PM UTC-6, wrote:
Not to start another chapter in "Battery Wars" but I have a simple question about "drop in" LiFePO4 battery replacements for SLA batteries in gliders.

For years, I've used an SLA battery with the same footprint as the common glider size of 7Ah to 9Ah--i.e., 5.95" x 2.56"--except a little taller--i.e., 4.61" high vs. 3.86" (specs are from the PowerSonic line but other brands are similar). It's an easy swap in my ASW 24, only requiring a different hold-down strap. There's about 20% more internal volume, which seems to equate to at least 20% more claimed capacity. I've used enough of these that I know they do perform longer than the conventional-size SLA batteries most pilots use.

However, I can't find a LiFePO4 equivalent for it. Does such a thing exist? All I've seen discussed here or available online seem to be the "traditional" size. I've been told that this is because there's already excess space inside the enclosure, that it's not packed to the gills with mat/chemicals as SLAs are, and that the extra 3/4" wouldn't allow adding additional cells. And besides, I don't need it anyway (I'm running PowerFLARM, radio, CNv vario, and PNA; no transponder yet).

Then I see that some LiFePO4 batteries are rated slightly higher for the same enclosure size. Even the K2 battery touted in adverts as "10 Ah" seems to be 9.6 Ah in the specs. And that's ignoring loads, discharge rates, temperatures, etc.

Given the price differential and the necessity for a new charger (although not according to the K2 site), and especially in light of the recent stories of LiFePO4 batteries crapping out long before their promised lifespans, maybe I should just continue to buy a new SLA battery every year or two and wait for this fad to pass.

As I said, a simple question.

Chip Bearden

I use these on my 29(sorry Richard), slides right in and my battery compartments are the same size as a 27.

https://www.bioennopower.com/collect...d-green-case-1

Not sure about your 24 size battery compartment. When measured are 5.95Lx2.96Wx3.66H. Last flight went over 6 hrs on one. My 10 amps are the same size and what I was using, I use about 1.32 amps per hour as I don't use the radio very much. Do have a Sandia transponder. When recharged it showed it had used 6.929 amps.
Used SLA's, now after using these would not go back. Have had no problems with them and 2 are now going on more than several years old and have well over 200 recharge cycles on them. I recharge them with my RC charger which I can set the charge rate. Been recharging them at 5 amps since new.

Ya, it's kinda late to your post, but may help someone else.

Best. Tom #711.

I used to sell Bioe until I got a bad batch 5AH for a 9 AH battery. They replaced but it took awhile.

Richard

How about this one?

https://www.batteryspace.com/lifepo4...ssed-dgr..aspx

I've been using these for 2 years now, and I am generally satisfied, having nothing else but Powersonic 12v 15 Mah SLA to compare, but I am still getting power above 12.8 volts after 5 hours running radio, S80, PowerFlarm and an old Becker 5401/3401 Mode C 250 Watt transponder.

Using the recommended charger overnight, I start the flight at 13.4 volts and after several hours at high altitude and OAT at 30 degrees F, I am still getting enough to keep everything happy. No complaints, except the built-in LED
pushbutton display is not visible unless I untape the inspection hatch and deal with the contortions needed to see the three power level indicators. No big deal, as there are voltage indicators on the S80, the Becker 4201 radio and my new Trig TT22 transponder. As well as a dedicated LCD voltage display (https://www.lascarelectronics.com/la...ment-emv-1125/)