LiFePO4 battery

Hi there,

Does anyone of you have any experience with LiFePO4 batteries in
sailplanes? I need to up my battery capacity, but have very limited
space in my ship. I read about them a bit, but ..... So, here are my
questions: is it worth buying this type of battery (they are quite
pricey), is the size comparable to sealed acid batteries (capacity to
size), any issues related to charging. Your input would be greatly
appreciated.

Jacek
Pasco, WA

Jacek,

I have a K2 Energy 12V10 battery (http://www.k2battery.com) in my HP-14.

If you search this news group you will see that there was a lengthy thread
on the subject about a month ago.

Wayne
http://www.soaridaho.com/


"ASM" wrote in message
...

Hi there,

Does anyone of you have any experience with LiFePO4 batteries in
sailplanes? I need to up my battery capacity, but have very limited
space in my ship. I read about them a bit, but ..... So, here are my
questions: is it worth buying this type of battery (they are quite
pricey), is the size comparable to sealed acid batteries (capacity to
size), any issues related to charging. Your input would be greatly
appreciated.

Jacek
Pasco, WA

On Dec 4, 5:18*pm, ASM wrote:
Hi there,

Does anyone of you have any experience with LiFePO4 batteries in
sailplanes? I need to up my battery capacity, but have very limited
space in my ship. I read about them a bit, but ..... So, here are my
questions: is it worth buying this type of battery (they are quite
pricey), is the size comparable to sealed acid batteries (capacity to
size), any issues related to charging. Your input would be greatly
appreciated.

Jacek
Pasco, WA

Hello Jacek,
I am using the K2 type for two years now and can only report positive
about it. The capacity is absolutely sufficient to keep my radio,
vario and PDA going for two days while the weight is almost half of
the traditional sealed lead acid type in the identical frame. You will
have to buy their charger as well but supposedly one gets more cycles
out of this battery type than the SLA's.
Uli

Jacek,

I'm using a stack of 2x4 A123 cells. It has 4,6 Ah and weighs only 700g.
Its volume is a bit smaller than the standard 7 Ah lead battery. By
buying single cells, you can build your battery in the shape you need it
and fit it to any unused space in your ship.

Erik.



Am 04.12.2011 18:18, schrieb ASM:
Hi there,

Does anyone of you have any experience with LiFePO4 batteries in
sailplanes? I need to up my battery capacity, but have very limited
space in my ship. I read about them a bit, but ..... So, here are my
questions: is it worth buying this type of battery (they are quite
pricey), is the size comparable to sealed acid batteries (capacity to
size), any issues related to charging. Your input would be greatly
appreciated.

Jacek
Pasco, WA

On Dec 4, 12:18*pm, ASM wrote:
Hi there,

Does anyone of you have any experience with LiFePO4 batteries in
sailplanes? I need to up my battery capacity, but have very limited
space in my ship. I read about them a bit, but ..... So, here are my
questions: is it worth buying this type of battery (they are quite
pricey), is the size comparable to sealed acid batteries (capacity to
size), any issues related to charging. Your input would be greatly
appreciated.

Jacek
Pasco, WA

Jacek,
The K2 10 Ah LiFePO4 battery (http://store.peakbattery.com/
12lfpba.html)
may be a great choice for sailplanes. It is in a standard 7 aH box so
it looks like the battery package you are used to. They have an
internal circuit board to protect from over charging, over
discharging, and it equalizes the individual cell charges when
charging it up. The flat discharge voltage curve means that more of
its capacity is available in a voltage range that your radio will
like. It is very light weight, and has a discharge cycle life of
2,000 cycles. The LiFePO4 chemistry seems to be about a safe as you
can get right now, combined with the internal circuit board, and a
fuse right off the battery,this battery seems to be a relatively safe
alternative to the standard SLA batteries. You will neet to buy a
charger made for this battery as the charging voltage is a little
different that what your SLA smart chargers are set up for. I have
heard of some people who now have two seasons on these batteries
without problems.

Now for the bad news. They are not FAA approved for use in aircraft.
Obtaining FAA approval is unlikely, as it is a very expensive process
to complete. All batteries are dangerous, this one included. Because
of its high energy density, and Lithium chemistry, this battery should
probably be considered more dangerous than your standard Sealed Lead
Acid Battery or "Gel Cell". It is definitly less dangerous than a
lithium battery pack that has a battery chemistry that supplies its
own oxidizer to the fire if the battery gets hot enough to ingite, and
does not have the proper protective circuits. It is expensive compared
to a single SLA battery, however if the 2,000 cycles is accurate, it
could end up being cheaper than using several SLA batteries in the
long run.

Should you use it in a sailplane? I can't answer that one for you.
Research the facts and you can reach your own conclusion, and assume a
level of risk you are personally comfortable with.