LiFePO4 Batteries

Thanks guys

Just bought a Tenergy LiFePO4 12.8V 10ah + Charger from all-battery.com

It has the Battery Management System (BMS) with short circuit, over charge and under discharge protection.

QUESTION: Any recommendations from other glider pilots on whether I should ALSO add a fuse on the battery before installing the connector for my ship?

BTW.. all-battery.com had a good deal. Total price $164.56 included free 1.5amp charger, tax, shipping and a $19.20 discount. Battery was $159.99.

Walt Rogers WX

On Saturday, June 14, 2014 1:15:51 PM UTC-7, WaltWX wrote:
Just bought a Tenergy LiFePO4 12.8V 10ah + Charger from all-battery.com



It has the Battery Management System (BMS) with short circuit, over charge and under discharge protection.



QUESTION: Any recommendations from other glider pilots on whether I should ALSO add a fuse on the battery before installing the connector for my ship?



BTW.. all-battery.com had a good deal. Total price $164.56 included free 1.5amp charger, tax, shipping and a $19.20 discount. Battery was $159.99.



Walt Rogers WX

Personally I would ALWAYS install a fuse directly on the battery pack as close as practical to the terminal post. The purpose of a power distribution fuse is to protect the wiring on the load side. While your battery pack may have some form of short circuit protection for itself, you have no way of inspecting it or knowing if protection for it, might mean less than 30 amps draw which would happily torch your wiring - with no harm to the battery. The fuse you install should be the appropriate size for the smallest wire it serves.

I purchased the exact battery and charger set from all battery. The battery and charger are made by tenergy. I got it January of last year and the battery started to fail at the end of last season. I was running out of power about 3 hrs into my flight.

Most recently, the battery voltage goes down to 5 volts under 1 amp load.

I called temergy and they told me the pcb is bad. They also told me that they can sell me one and if I cut the case open I can simply install it myself and glue the case with jb weld. Not exactly what I wanted to hear after spending $160 on a battery that is supposed to outlast a regular sealed lead acid battery.

Keep Iin mind that their warranty is very short. I would buy somewhere where the warranty is much longer.

Marcin

Send me your battery (postage paid) and I'll happily repair it and use
it in my ship!

More seriously, I bought my Tenergy 10 Ah battery from Amazon for $153
and it included a charger and shipping. I installed a fuse within one
inch of the battery and, at least for a year, I will take the battery
home to charge rather than leave it plugged in at the airport. One
night I forgot to unplug it and, in the morning, it was cool to the
touch, fully charged, and accepting no current. I also have a Watts Up
inline power meter which records voltage, current, and power dissipation
and was surprised to see that my peak amperage is 2.8 amps in service!
I suppose that means when I transmit and my transponder is replying at
the same time, plus computer, Streak, etc...

Dan Marotta

On 6/14/2014 4:39 PM, Marcin S wrote:
I purchased the exact battery and charger set from all battery. The battery and charger are made by tenergy. I got it January of last year and the battery started to fail at the end of last season. I was running out of power about 3 hrs into my flight.

Most recently, the battery voltage goes down to 5 volts under 1 amp load.

I called temergy and they told me the pcb is bad. They also told me that they can sell me one and if I cut the case open I can simply install it myself and glue the case with jb weld. Not exactly what I wanted to hear after spending $160 on a battery that is supposed to outlast a regular sealed lead acid battery.

Keep Iin mind that their warranty is very short. I would buy somewhere where the warranty is much longer.

Marcin

Thanks for your offer Dan :-)

I ended up installing an additional battery http://www.bioennopower.com/collecti...ed-low-profile

So now I have over 30 Amp hours

They also offer a two year pro-rated warranty.

Marcin

On Saturday, June 14, 2014 6:39:13 PM UTC-4, Marcin S wrote:
The battery and charger are made by tenergy. I got it January of last year and the battery started to fail at the end of last season.

Most recently, the battery voltage goes down to 5 volts under 1 amp load.

I called temergy and they told me the pcb is bad.

This failed PCB is the component that protects the battery from other (very) bad things? Is flying with a half-broken LiPo battery different than flying with a Tost hook that has only one broken spring?

That's a vote of one... for using a fuse on the battery.

Bought the Tenergy because of recommendations of fellow glider pilot friends and good customer service. Actually, I was intending to pay a little more for the K2, but at Batteriesinaflash.com, the customer service guy told me that they weren't available from the company for up to 45days. Batteriesinaflash.com doesn't carry the Tenergy because "...the K2 is a better battery". The next day, I received a return call from the company rep, K2... and as it turned out could have picked one up from them or WingsAndWheels. K2 says that their BMS is better quality and same for the battery all the way through. Of course, it's a little more expensive. Based on WingsAndWheels and David Springford's business, it appears other have come to the same conclusion that the K2 is a better battery.

Let's hope infant mortality on my Tenergy BMS won't show up for awhile. The price on the Tenergy 12.8V 10ah with free charger was $160 minus $19 discount before taxes and shipping. So, it appears that they are discounting them a bit... probably because of more failures.

Walt Rogers WX

Correction... two for two voting for a fuse on the battery.

Walt WX

Personally I fit a Klixon 7277, 7.5A circuit breaker right next to the
terminal. Same principle, but if it trips for a good reason I can find,
I'm not searching for a spare fuse just before take off.

Same idea, different solution.

At 00:58 15 June 2014, WaltWX wrote:
Correction... two for two voting for a fuse on the battery.

Walt WX