Battery Wrap

[kippid]

I got my Arrma Kraton running finally. I'm running two 8.4v NiMH batteries in below freezing temperatures. The batteries get crazy hot after a run. After a few cycles I notice my shrink wrap starting to develop holes and wear. After my 6th run it appears my shrink wrap has melted so bad the pack will fall apart. The batteries look to be in great condition still.

Is the only smart method of rewrapping them shrink wrap?

Any suggestions?

Is this normal wear?

find me on youtube: CANTSiR

 

[slick2500]

If your batteries are getting hot enough to melt the shrink wrap they are highly under powered for your application. Hot batteries is always a sign of the battery not being able to keep up with the amp draw of the power system in your rc.

 

[kippid]

It's just exceptionally cold. 16.8v far exceeds minimum volt specs.

 

[kippid]

btw NiMH dump amps as fast as systems can take them. That is simply how NiMH works. They don't have C rating because of this.

 

[slick2500]

How cold is exceptionally cold? I have always been told not to run my rc cars when the temps get below about 20*f as these temps have a negative effect on the battery.

 

[WTF MIKE]

Time to get lipos and never look back

 

[kippid]

NiMH have a safer tolerance to cold which is why I am running them specifically. It says its 30 degrees here for 5th n 6th cycle. It was 17 degrees this morning for my first 4 cycles.

 

[kippid]

I own a high quality 6S hardcase lipo. I am not dumb enough to blow it up in 17 degree temperature.

 

[WTF MIKE]

I run lipos in the cold with no issues yet the coldest being -15c

 

[kippid]

u run soft or hard case? find it hard to believe u haven't had swelling at the least

 

[slick2500]

Well the batteries are getting way to hot so something isn't quite right. Either there is a high resistance load between the batteries and the esc or the batteries are not capable of providing enough amperage.

 

[kippid]

I do run the batteries til they are dead. I pushed the car to use the very last bit of battery energy. Hobby shop dude said it makes no difference. Maybe I should stop once I notice batteries are fairly dead? Maybe a mid run temperature inspection?

 

[WTF MIKE]

u run soft or hard case? find it hard to believe u haven't had swelling at the least

I had only one battery swell on me. It was an onyx 6400 mah 3s but I was new to the hobby and I couldn’t figure out how to adjust my charger.

 

[WTF MIKE]

All soft cases

 

[kippid]

the temperatures on all my other parts are cold.

 

[Mr.Duke]

I've never heard of or seen a lipo explode because they're being run in cold temperatures. Performance loss yes, but that's what's to be expected as the primary drawback for running them in freezing temperatures.

 

[kippid]

supposedly they gel up overheat and burst if too cold

 

[Mr.Duke]

How is it possible for them to be so cold they've gelled up but generate enough heat to become too hot and overheat?

 

[kippid]

gel up causing rupture of chemical separation to become combined causing flash heat n burst. just lazy writing i guess.

 

[kippid]

stick magnesium in water and ull see two cold things burst into flames