Repairing holes in a battery pack

[Cupooterluvr]

OK so I took my RC18 pack out of the car for the first time in a while because it was charging hot. Upon doing so I saw that it actually had holes worn into the plastic. What's the best way to repair this?

Also, it keeps charging at like 140 degrees for some reason. Any thoughts? I haven't actually monitored it while charging but that's what it is at after the charger peaks.

 

[CharliesTheMan]

Are you making sure to let the battery cool down for about an hour after running the RC, and letting it cool down for an hour after charging it, before you run it again?

 

[Cupooterluvr]

Yeah I let it cool. I was just wondering why it was getting so hot.

Well I have a theory. My garage gets pretty hot. There's a fan on the desk where I charge it, do you think I should have that running while it's charging?

 

[CharliesTheMan]

What size battery is it and what rate are you charging it at?

 

[Rolex]

Put up some pics of the holes. Wondering if they are worn through, eaten through or burned through.

 

[Cupooterluvr]

Here are some pics. The first one is a little blurry, sorry.

The ones on the bottom and top of the battery look worn through but I'm not sure about the sides. It looks as if something got in there and slit the plastic open.

Oh, and Charlie, it's an 1100 pack and I usually charge it at 2 amps with a Dynamite Prophet Plus peak detection charger.

 

[Rolex]

That's not looking good. The ovals on the sides look like they have gotten WAY too hot. The blue wrapper is shrink wrap, and the hotter it gets, the more it shrinks. When it shrinks TOO much, it will tear and leave that oval hole.
You probably have one or more bad cells in there. Time to replace it.
Going back to an earlier question, at what rate were you charging them?

 

[Cupooterluvr]

Aww man. It's a nearly new pack too. It doesn't look it but I've only had it for about 2.5 months.

I actually was starting to think it was going bad because I'm only getting about 5 minutes of run time now, whereas before I would get about 15-20 minutes.

On another note, are the Reedy batteries better for durability?

 

[CharliesTheMan]

man I've gotten some batteries REALLY hot and never warped or put holes in the shrink wrap. That thing must have gotten quite warm.

 

[Rolex]

I can't tell by the pics, but is it NiCad or NiMH?

 

[Cupooterluvr]

It's NiMH. I think the problem is that my garage gets up to around 100 degrees in the morning sun. The sun shines directly on it for about 6 hours. That might not provide the cooling it needs.

I think the reason it has holes worn in it is because I was running it in dirt and didn't get it all out of the tray :\


EDIT: would some foam tape in the bottom help with shifting and the wear and tear?

 

[CharliesTheMan]

I think a lot of the wholes are from wear, but those ovals that Rolex pointed out are a tell tale sign of the shrink wrap getting way to hot. You should probably be charging and especially storing your batteries in a better environment than a hot garage, but I think you still might be charging at a very high rate and causing the batteries to get way to hot. For that battery, I would probably charge it at around 3 or 3 amps max, unless it's much bigger than i think it is.

 

[Cupooterluvr]

My charger only goes up to 4 amps, and usually I charge it at 2 unless I really want it to be done quick.

 

[Rolex]

You can push a NiCad to double, like charging a 1500 at 3 amps, but from any information I've ever gotten, NiMH is charged at its' current rate. 3000, 3 amps. 3300, 3.3 amps max.
Maybe others push theirs, but I've never done it to mine.
The first charge on a new NiMH should be at half its' rate.

 

[Cupooterluvr]

I thought NiMH's could be fast charged? I guess I'll put it on 1 amp from now on.

 

[Mattyfats420]

I've had a battery do that because i didnt pay attention to it. you can tell what cells are bad when you charge it cuz they will instantly get hot and stay hot for a while. looks like you got one or more bad cells in there. i would get a new battery just in case

ok so i got a 2400mAh battery pack.. i would want to charge that at 2.4 amps right? is that what your saying rolex?

 

[Rolex]

Correct, if it's NiMH. If it's NiCad you can go to 4.8 amps.

 

[Mattyfats420]

Great thanks alot, i was charging my stuff at twice that At Least! ouch. good thing i only did it a few times. batteries are expensive! and i want them to last for a long time!

 

[Rolex]

You don't want to charge them when they're hot right out of the car, either. Wait for them to cool off completely.
After charging, let them cool before using them.

 

[HeartBreak]

Rolex beat me to it... You're also lucky the batts didn't hiss and pop on you. Charging them faster than they're able to take a charge can result in a nasty mess.

The carpet in my parents' front room was living proof (until about 4 years ago when it was replaced).