LiPo Battery Storage - WARNING!!!

[KarbonBird]

Have been grounded for the past week due to bad weather - with all my 10 battery packs charged and ready for action when the weather improves.

Having lost about 10 liPo batts (eWatts) about 6 months ago due to puffing ... I have since replaced them with 2170 mAh Flightpowers BUT now I am worried...see here:

(Should I only be charging batts just before use????)

http://www.wattsuprc.com.au/

Did you know??

All the batteries used on T-rex 450, T-rex 600 and T-rex 600N BEC are Lipo batteries which need to be taken more care of compared to other types of batteries.

For Lipo batteries, you should not just pay attention on over-charge, over-discharge and also on the battery storage environment.

According to the testing, we found the higher discharge rate the battery has, the shorter durableness of the storage of the battery is.

Generally speaking, to avoid the swollen, you should discharge the battery in 6 hours after the battery is charged. Both JK and Allan mentioned that they charge their batteries one to two hours before they fly their T-rex 600 and they only charge the batteries they need to fly the heli every time.

For all Lipos, many flyers charge them once they get back home after flying and leave the batteries for 2 to 5 days, and they found the batteries start to swell.

Did your battery get swollen due to this reason??

[crewchief]

I lost an expensive 5000mAh Thunder Power with only about 30 cycles, but I have 2 MaxAmps with nearly 100 cycles and no loss of power. Both have been left charged for days, so that's not the reason. I think how I frapped the TP was by not using the proper balancer and also I overdischarged it while test flying a heavy camera mount. I now try to set my timer to have more than 22.5 V left at the end of the flight, and I only order batteries with simple Astro Blinky taps. I don't know why the H*** TP has to use that complicated double-tap system.

[jaywhy]

I'm new to the hobby, so all of my packs have gotten charged and sat for days, maybe even 2 weeks or more? 3 of 4 are puffy. 1 is the align POS, so obviously. The other 3 are the hextronix.

Glad I haven't bought a spendy lipo yet! I'm guily because I knew folks were saying dont leave `em charged more than 3 days without discharge to storage level...

[bullaculla]

I used to leave my FP evo20s and evolites fully charged for weeks. Not one puffy lipo, except my crappy align 4200 which puffed from just being crappy. I dont leave them fully charged anymore just to be safe. 50% is supposed to be a safe storage charge.

[KarbonBird]

OK just to be on the safe side I have dropped the 2170 Flightpowers (11.1) to 11.50 as this is what the batteries arrived charged at.

[phil007]

This was one of the reasons I went to only using A123 battery packs.

Phil

[Cryofix]

Full charge over 3 months at an average of 90 Degress F will kill a batteries capacity by up 60-65 %

So say you charge your batteries and have to go on a trip and takes all summer, you store your batteries in your garage of the 3 months, they will be toast when you get back to them.

Best possible scenario for a lipo is 50% charged and stored in a refrigerator, right about 40 degrees is optimal, I have a small fridge i use for sodas and beer, and now lipos.

[KarbonBird]

Full charge over 3 months at an average of 90 Degress F will kill a batteries capacity by up 60-65 %

So say you charge your batteries and have to go on a trip and takes all summer, you store your batteries in your garage of the 3 months, they will be toast when you get back to them.

Best possible scenario for a lipo is 50% charged and stored in a refrigerator, right about 40 degrees is optimal, I have a small fridge i use for sodas and beer, and now lipos.

Interesting thanks .... just 2 questions:

1. So what voltage should an 11.1V 3S lipo be chaged at then for storage - bearing in mind that the thing goes up to 12.6v when charged.

2. What about the moisture in the fridge - won't it damage the batts?

Thanks

[hfgencollon]

a fridge? can you point out your source for us? I have never heard this before.

[bullaculla]

Best possible scenario for a lipo is 50% charged and stored in a refrigerator, right about 40 degrees is optimal, I have a small fridge i use for sodas and beer, and now lipos.

I have the same thing, a small fridge for bottled/can drinks, and I tried to store lipos in there. the problem I had is when they get out they sweat like mad cause its so humid in here. I had to wrap them up in a towel and let them warm up slowly.
It was pretty scary seeing all my lipos covered in water :shock:


2. What about the moisture in the fridge - won't it damage the batts?
Thanks

I kept mine in the little align alum case for the 450. the problem was like i said above when you need to take them out.

[kgfly]

KarbonBird - What charger do you have ? The better ones all have a Storage mode which charges the packs to the appropriate storage voltage (3.75-3.85V/cell). Since you are in W.A. and it certainly can get very hot, storing in the fridge might be wise. Or maybe consider storing them in an esky with a freezer block that you swap over every few days in the hot weather. You want to keep them under 20C if possible.

For what it's worth, I have cheap HXT packs that I keep charged all the time and store in a pyrex casserole dish in the house. They are over a year old and over 100 cycles each and still working but showing signs of age.

I have lots of A123 cells on the way now :)

[Cryofix]

This link is a Credit to Dale Hart he was telling me about when I check this out..

http://rclovers.com/GetTheMostFromLipo.htm

[Pyrock]

I have lots of A123 cells on the way now :)

I, too, am looking into A123's for my IonX and possibly for my Logo 103D. It seems like Lipos are getting more and more fragile as we learn more about them.