Question about re-wraped battery

[Andromendous]

Hey all, I was re-wraping one of my Samsung 30q's and I lost the little white insulator "donut" that goes around the positive post, out if frustration I went ahead and finished the job. I got it to cover where that insulator would be, do you think its still ok to use? Or is that insulator absolutely needed?
Thanks.
As you can see, theres no white insulator around the positive terminal

 

[zoiDman]

If the Insulator wasn't necessary, I'm sure that all the Battery Manufactures would just skip putting it on.

Why don't you set that battery aside and get a 20-Pack of these Insulators.

18650 Flat Top Battery Terminal Insulators - 20pcs

 

[Zack42]

I agree just get new batteries spend couple of dollars and buy yourself a peace of mind.

And to answer your question, it is important. Manufacturers will do anything to save money, so if that part wasn't important they wouldn't have put it there. I wouldn't mess with the batteries, the risk is too high for the cost of a new one.

 

[Completely Average]

The reason the insulator is important is because the center post is positive, but the entire outer casing is negative, all the way to the top of the battery. If by some weird chance you got a small piece of conductive anything under the edge of the wrap it could create a runaway short circuit and overload the battery.

 

[Ed_C]

I almost lost one of those pesky things myself when I re-wrapped some batteries the other day. Those things like to run away.

 

[Andromendous]

I almost lost one of those pesky things myself when I re-wrapped some batteries the other day. Those things like to run away.

Thanks for the responses everyone. I'll just put it away for now. I was using a hair dryer to heat it up, and the darn thing blew away. What a shame.

 

[K_Tech]

Thanks for the responses everyone. I'll just put it away for now. I was using a hair dryer to heat it up, and the darn thing blew away. What a shame.

Do you drink milk? I ask because the plastic that milk jugs are made from makes an excellent insulator in a pinch. Just cut yourself a little circle of plastic and replace it.

And if you don't want to make one:

18650 Positive Terminal Insulator - 6 Pack

 

[retired1]

Moved to Batteries and Chargers

 

[Mooch]

That insulator ring is critical! If the wrap is pulled back even a little bit the ring is the only thing preventing a short circuit.

You can use almost any plastic or card stock as a replacement, even a old birthday card, and cut out a new ring. Double the thickness if necessary.

 

[DaveP]

^^^^ This ^^^^

Wraps are very likely to crack or tear in that spot because it's the end of the battery that people pull first coming off a charger. They catch on the charger contact and the wrap cracks. The only way to prevent the positive end from cracking is to hold and pull toward the negative end when inserting and removing them from the charger.

Manufacturers need to use taller spring loaded negative contacts so that we can pull back the contact to lift the battery without breaking the wrap. They could put a rubber tip on it to insulate the part we touch. That might interfere with chargers that need clearance for 26650 cells. They could slant the top part, though.