My nimh batteries froze outside

[treehugger]

So I was out in the yard with my 10T. I put one battery through it and a friend came over and one thing led to another and you guessed it, I left three packs sitting on the back of my car. The next day after a mild frost I discovered my batteries.

Have I done any damage? Any insight would be great.

[harry697]

I would throw them on charge and see what happens.I've left packs outside overnight in the winter before by accident.Never really had any issues.However,I left my favorite nimh race pack in my shed last winter for a month or so and one of the cells never fully recovered.Still ran pretty good after a few cycles,but it was never the same.

[giggles]

i would agree try and through a charge on them i had a 12v gell battery i bought in 2000 and it sat outside in michigan winters my dad sent me a pack of my rc stuff he found in the garage and the bat was there it still had a charge so i put a charge on it i now im using it in one of my starter boxes i guess somthis u just cant tell what a batterys going to do

[illshou]

It's probably like a full sized car bat. If it was charged up when it frose it's more than likely still good. If it wad dead, probably garbage now.

[Jeep-Power]

The battery should be fine-

we used to throw the batterys in the freezer when charging-- they would peak alot higher.

I used to bring a cooler to the track to keep 'em cool before heats-- -- gave great punch off the line!

[treehugger]

well none of mine survived the experience they last for about 1 minuet then die its a bit of a sore point two set were a week old

Paul

[Jeep-Power]

wow -- that's a huge bummer.

I forget-- we were using 1400mah NiCd back then. I haven't tried it with a NiMh.

[treehugger]

well it decided the fate of weather to invest in li po i just have to find some the market is staggering and i dont know much about them

Paul

[Jeep-Power]

I'm just getting into Lipo myself-- I find the C rate (discharge rate-- a 30C 4000Mah battery can discharge at 12000Mah-- a 20C 4000Mah battery can discharge at 8000Mah-- atleast that's how I understand it) is key-- for a speed buggy-- it seems at least 25C is mandatory-- as far as I can tell, if a Lipo battery is discharged above it's C rate, it causes harm to the battery (if it gets shorted out, as in a crash-- it can blow up).


Then there is the need for a Lipo charger. Lipo can be charged on a regular charger, but the risk of (at the very least) harming the battery or (at the worst) the battery will burn up/explode.
I have a Hyperion EOS606i -- it is great.

[THEYTOOKMYTHUMB]

well it decided the fate of weather to invest in li po i just have to find some the market is staggering and i dont know much about them

Paul

There are a lot of opinions. If you want to get in cheap I recommend these if they ever get back in stock. I have not personally used them, but I know people who have and they haven't had any problems. Shipping is much more reasonable than HK prices. This charger seems like a good way to go too. Again, it's a cheap way in. A lipo cut-off is a wise investment, but if you monitor your runtime and stop before performance drops off you can be ok. You can then hook it to the charger and see where you're at on voltage. If they drop too low in voltage it can damage them.
http://www.hobbypartz.com/40c2s.html

http://www.hobbypartz.com/thac6smbachw.html

Good info here for more details on lipo batts
http://www.maxamps.com/lipo-care.php
If you want to spend more money, I can't say enough good things about Maxamps and Hyperion
This is intersting too, but you have to read it all to really understand how they did it. Kind of a strange system to judge by.
http://www.bigsquidrc.com/lipo-battery-shoot-out/

[slotcarrod]

well none of mine survived the experience they last for about 1 minuet then die its a bit of a sore point two set were a week old

Paul

Hey Paul, they should be fine, I freeze mine all the time! Just cycle them a few times, they will wake up!

[treehugger]

cool ok rod thanks they were in the recycling pile wife nearly took them this week

Paul

[G-spec]

Back in the days of NiCd/NiMH, there was a machine (forget the name but looks like a jumbo size charger) that could litterally zap a dead/frozen cell back to life. Sneeky racers would use it to get a little more juice out of their packs at the track. Not sure if this machine still exists.