smeyers2

Just got a pair of Hyperipn 2s/7.4 35C... I charged them up a few days ago... THEN I found a battery care sheet.. it said DON'T fully charge them and let em sit for more that 2 days max. It will shorten the life of the battery. Charge them the night before or day you're going to use them. I discharged the bats using a couple of 12 volt auto bulbs. After an hour the battery was down to 7.4. I took my eye off it for a second and took a look at it. The bulbs were not lit and the battery was slightly warm. One cell was 1.9, the other was 2 something. I put it on the charger... off course I got an error message.... Cell 2 too low. Charge cancelled. I set the charge to 1/2 amp and it started to charge. After the volts on each cell were over 3 I upped the charge to 2 amps and gave it a 95% charge at 2 amps. During the charging I constantly monitered the temp... it stayed at 75 degrees. I thought all was fairly well and I may have escaped a bullet. But I notice that the battery in question is ever so slightly swollen compared to the other battery.

I'm afraid to use it thinking it might catch on fire when I put a good load on it. Not buying another battery might save me $100, but I might loose a $700 car if it catches on fire.

Any thoughts besides I'm An Idiot !!!

Neu_Racer

iTrader: (211)

I wouldn't say you are an idiot but this should be posted in the "lessons learned" thread.

ALWAYS ALWAYS ALWAYS discharge your lipos by running them in a car, not on a charger. Unless of course you only need to drop a couple mah of juice but this is not an uncommon occurence.

If your battery is puffed there are "fixes" to help decrease the chance of fire but IMO the best fix is to eat the $100 and buy a new one. Sucks but I have actually had a $700 1/8 buggy burn from a MaxAmps 2S lipo and there is no worse feeling in the hobby. Destroyed everything in the car and there was no sign of damage to the pack before running it, just blew up.

Good luck with whatever you choose.

smeyers2

Thanks for the reply....

I was leaning towards eating the $100 and getting another battery. I'll have to get a lot of catsup to eat it though!

Nite !!

Duster_360

iTrader: (21)

I'd watch it for a few days - if it puffs any more, even a little, I'd replace it and move on.

I've seen this with SMCs and they go back down and continue to work. Its really a matter of what you're comfortable with ultimately.

vedardo49

iTrader: (6)

ill buy them

jrxsMike03

iTrader: (14)

if it reads to low try charging it on nimh for a few minuets not the whole charge this will bring the volts back up and you can charge on lipo again. I've done it before should work. good luck the batteries are probably still ok

blade329

iTrader: (114)

The Hyperion chargers have a "store mode" that is really a life saver in situations like this.

UK.hardcore

My advice, you should have left it sit fully charged.

Mine are always 100% charged, i see no harm nor loss of performance.

Bugle

iTrader: (1)

Yeah, the issue here is that it was over discharged not that it was left fully charged. I've left batteries fully charged for weeks and they've been fine.

jrxsMike03

iTrader: (14)

i leave mine fully charged never a prob. let us know how it works out for you.

Neu_Racer

iTrader: (211)

Correct but I believe the issue was he discharged them on a charger because he read it was bad to leave them fully charged. As one person suggested, the Hyperion chargers (and many others) have store modes which drain the pack to around 60%. Or run them in a vehicle which is the more fun approach IMO.

But personally, I run Zippy packs and leave them fully charged for days/weeks and even months with zero problems. Heard thats not recommended for SMC packs though.

Bugle

iTrader: (1)

Nah he didn't use a charger to discharge, he said he used some 12v globes
Definitely best to use a charger, even if it takes hours, most seem to be able to only discharge at 1 amp..

SuperEk4

iTrader: (32)

Yap it's screwed never discharge using other means other than charger or car(with cut off)

I tried charging one of my 6s with 1 cell too low. Can charge the cell up but end up the whole batt was warm n I stopped. But at the end 2 cells died, I hv to strip the batt to 4s.

rclugnut

iTrader: (1)

some packs like zippies you can leaving around but some higher end packs you need to use them within 48 hours, personally if it takes a few charges i would run it very lightly and see how it does, if there is any puffing and it doesn't go away after this i'd buy a new one if it does i'd say you're lucky

but about discharging the BEST way to do this is in your vehicle even if it is a measly 1000mha on a nihm that you let sit for too long it does wonders for the packs i've had nihm's jump from 1000mha on charger discharge and charge multiple times then ran it in my car jumped to 3500mha

the lug

smeyers2

Thanks Everyone For Your Answers...

Playing it the safe way I ordered another battery. I have the one in question in an empty tool box with the lid secured, sitting on my stove (only fireproof thing in my house LOL). It hasn't puffed anymore. I'll use it in a smaller car... probably my slash, and see what happens.

HAVE A GOOD WEEK !!!