Wear and tear on Battery Wrappers

[Mrez]

After posting in another forum regarding a either short, or continuous fire situation, I wanted to come to the battery experts here and ask a stupid question. I've noticed over a fairly small amount of time, some of my batteries have little tears in the wrappers along the body of the cell. The tears are small, and I haven't really had an issue before tonight. Basically, after said, issue I noticed that the battery that was a bit stressed is showing slight burn marks/dark edges around the areas where the wrapper has small tears in it. After the continuous discharge, i tested it out on my charger and it was at 3.5 V (which is where I normally switch them out), and it is charging right now on my nitecore at .5 amps with no issue.

Are small holes in the battery wrapping likely to cause a short or continuous fire situation?

 

[Froth]

Yes, it is entirely possible to cause an auto-fire with a small hole in the battery wrapper. If you have a voltmeter/DMM with probes you can probe the positive post and whatever little hole in the wrapper there is to see if voltage will pass through it. From experience I can tell you that it will.

 

[AzPlumber]

In a metal mod a torn battery wrapper can cause an auto fire. The can (outside metal tube) of a battery is also negative just as the bottom is. If the can is not totally insulated (torn wrapper) it can arc across the short distance to the metal frame/tube of a mod and will auto fire some (most) mods.

 

[Mrez]

Thanks guys, I've been wondering about this. This really rather sucks as three of my four cells have little micro holes in them here and there. You would think they would make the wrappers in a better material.

 

[AzPlumber]

You can buy 3/4" shrink wrap at most hardware stores and re-wrap them using a hair dryer. Make sure to remove old wrapper as the batteries won't fit in most tubes with two wrappers.

 

[edyle]

Thanks guys, I've been wondering about this. This really rather sucks as three of my four cells have little micro holes in them here and there. You would think they would make the wrappers in a better material.

The batteries simply aren't designed for bottom fired tubes.
They're designed for regular flashlight tubes with a spring at the bottom which connects the negative to the tube; so if the metal side of the battery also makes contact with the tube it just makes a better electrical connection than having to depend on the spring which is really there performing both a mechanical and electrical function.

 

[Mrez]

A follow up question. I'm pretty sure at this point I had a short from the holes in the wrapper. I checked the battery on my nitcore charger and it was still at 3.5 v and it took a charge at .5 amps up to about 3.9 v. Took it off the charger to go to bed but I plan on fully charging. The battery itself as far as I can tell never got to hot to touch. Most of the heat seemed to come from the Atty and body of the mod. Is this battery still use able? It is a VTC4.

 

[Hawaiian Nate]

http://www.illumn.com/18650-battery-pvc-wrap-blue-pre-cut-10-pieces.html

Try these out if your battery wrappers are getting torn up

 

[edyle]

A follow up question. I'm pretty sure at this point I had a short from the holes in the wrapper. I checked the battery on my nitcore charger and it was still at 3.5 v and it took a charge at .5 amps up to about 3.9 v. Took it off the charger to go to bed but I plan on fully charging. The battery itself as far as I can tell never got to hot to touch. Most of the heat seemed to come from the Atty and body of the mod. Is this battery still use able? It is a VTC4.

it doesnt sound like you shorted out your battery; the battery just run continuously connected to the load; plus although I don't see what the load was it doesn't sound like a serious subohm load like 0.2 ohm and your battery only went down to 3.5 volts so it didn't get anywhere near the danger zone.

 

[Ryedan]

A follow up question. I'm pretty sure at this point I had a short from the holes in the wrapper. I checked the battery on my nitcore charger and it was still at 3.5 v and it took a charge at .5 amps up to about 3.9 v. Took it off the charger to go to bed but I plan on fully charging. The battery itself as far as I can tell never got to hot to touch. Most of the heat seemed to come from the Atty and body of the mod. Is this battery still use able? It is a VTC4.

I agree with edyle, it's fine. Also, here's a tutorial on how to re-wrap a battery.

 

[Mrez]

it doesnt sound like you shorted out your battery; the battery just run continuously connected to the load; plus although I don't see what the load was it doesn't sound like a serious subohm load like 0.2 ohm and your battery only went down to 3.5 volts so it didn't get anywhere near the danger zone.

Ive come to a similar conclusion. The battery took a full charge. I was running a dual twisted 26 gauge wire coming in a .35 ohms on a plume viel clone. I took it apart today and in addition to the delrin in the top cap being melted, the insulator around the connector pin was melted out. I had a spare from another clone that was no good and put it back together. I think what happened was I had just over tightened it, the contact pin on that atty was always a bit longer then my other atty's. To get everything lined up right I always over tightened it. I think when i set it down it was just enough to make a slight contact. Interestingly to me, the rayon wicks and coils were unburnt and still useable (though I stripped them out). So at least the battery is still good when I get a new wrap on it, and the atty is still useable, though I am not sure I'm going to tempt it.