Tutorial: Rewrapping a battery

Thanks for the tutorial

I have several metres of green shrinkwrap suitable for 18650’s - anyone in the EU who wants some - PM me - the cost will be the postage plus a few pennies. The cells I needed to rewrap have been rewrapped. Happy to supply it in 75mm chunks. And don’t pay till it arrives. Experience there.

Thanks for the tutorial!

Question, isn’t the heat shrink too tight? I know that you need your heat shrink to be 3-5mm wider than what you intend to wrap. If the typical diameter of a 18540 is 18.5mm, how does your 18.5mm shrink wrap fit with a bit of room to spare? I was wondering if I should go a bit bigger by 3-5mm to be safe.

The internal dimeter (unshrunk is 18.78mm). “Circumference” of the flat stuff is 59mm. So 59/pi gives the “diameter”.

it is tight but it works, like i mentioned this shrinks not so much thats why my 16340(16mm diameter) is not so tight shrinked than my 18650.

No, as long as it can be pulled over the battery it is fine.

I have added a table with diameter and minimum width of the heat shrink tube for the common battery sizes. If you buy from somewhere where they do not specify that it fits a specific battery, I would recommend to get at least 1 mm extra.

The larger the heatshrink, the thicker it will get. So for most flashlights its best to use a heatshrink that doesnt have to shrink very much.

Thanks for clearing that up guys. I didn’t want to end up picking up the wrong ones.

Thanks for the write up HKJ. Just broke the wrapping on one of my keeppower 18650 and was looking for the wrap to fix it.

That is actually easier than I thought.

nice crisp tutorial thanks!

;)

awesome tutorial

I agree.

Super job!

Thanks. An excellent write up.

Fine tutorial

Nice tutorial and thanks for all the extra info on supply and sizing. Really helpfull.

Thanks for posting this tutorial. Very Nice!

Great info, need to do this on 2 batteries and stop using tape on em. Didn’t think a hair dryer could manage. Now I know. Thanks

That was the reason I made this tutorial. It is easy and cheap to make a good repair, instead of doing a unsafe repair.

I did play a bit around with the hair dryer, coving part of the air intake with a hand, did increase the temperature and made it faster to shrink the heat shrink, but be careful with doing it, it can damage the hair dryer.

Does anyone have another source for different collars ? And I have some 18650 and I need button tops where can I buy them