Tutorial: Rewrapping a battery

I have not tried with adhesive, but I will not expect any different when rewrapping, the final result will probably be a bit stronger.

I have ordered this shrink and it is without adhesive glue whatever…just blue plastic which is a tight fight on a 18650.

pictures in another thread:

I also rewraped a 16340 with the fasttech shrink, this worked but the wrap doesn’t get perfect plain…

Thanks for the confirmation!

Nothing but red x’s…can’t see the pics.

Looks like the server is down, it will probably not take very long before it is up again (I uses a hosting service).

Cannot see pics at the moment.

They are back again.

Nice, thanks!
I have re-wrapped some batteries, did not bother to measure the wrapper before cutting. Just estimated it by eye.

I think after re-wrapping it feels at least as much if not more durable than before.

HKJ gives good advice.

I use a Laundry Marking pen from the Office Supply to mark cells. This is better than the so called “permanent marker”. The Laundry Markers are the ones that never wash out of clothes, even in hot water. Don’t get it too oily before you mark it.

If you mark it….better check your spelling first, you ain’t gonna change it.

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!