Rewrapping a battery

vicgarbutt

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Jul 8, 2017
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I only used a good hair dryer. You never had the hair dryer remove the crease, only with the use of a lighter?


You can also use an electric stove elem,ent to generate the heat needed for a nice tite clean wrap
 

WalkIntoTheLight

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Good tutorial. I'll just add a couple of things for flat-tops:

1. Save the plastic insulation ring from the positive end of the battery, assuming it's not damaged. You can re-use it. Otherwise, you'll have to get a replacement ring.

2. If you're using a blow-dryer, you'll have to hold the plastic ring down with a finger, until the positive end starts to shrink (so do the positive end first). Otherwise, the ring will blow out of the tube, and you might have to use another wrapper and do it all over again.
 

HKJ

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Copenhagen, Denmark
can a 16340 be rewrapped?and if so where can one find appropriate wrap?

Of course it can be rewrapped, you just have to find some shrinkwrap of the right size. You may not be able to find it precut, but may have to cut it to length yourself.
Look for shrinkwrap on Ebay, in Vape shops and electronic parts shops.
 

slumber

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I picked up 2 meters of clear 16340 wrap for less than $2. I use it to add some width to a few CR123's in order to reduce battery rattle on lights that don't require frequent battery swaps. Works well.
59ac43af83f247d901ec483287c1fb26.jpg
 

thermal guy

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ny
So I have a few keeppower 18650 that the tail springs on my light have eaten away at the negative end of the battery making for not so good contact. I remember seeing replacement brass "I think"disks for this. But can't remember where can anybody point me in the right direction? Thanks
 

chrissybabe

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Nov 22, 2013
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After much experimentation I found the best way (for me anyway) to re-wrap a battery is to cut out several pieces of heat-shrink using a guillotine and they all end up being the same length with the ends square.
I use a proper heat gun and try and stick the battery vertically on a small flat spacer so the heat-shrink drops down lower and covers the spacer. Then I get a consistent overhang of the tubing around the ends of the battery. Careful even application of heat is required so that wrinkles don't develop. I saw a comment earlier about how do you get the side creases out. I take the un-shrunk tube, open it out flat so the creases are in the center of the flats then on a flat surface run a fingernail over the crease to 'iron' it out. This seems to work fine on all the different types of tubing I have tried.
 

desert.snake

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Shrinking and Kapton tape are very cool solutions, but if nothing is at hand, then ordinary stationery tape also works, only 1 minus, in the heat the glue can ooze from it and you will have to rinse the flashlight from the inside with alcohol, if stickiness bothers, of course. Medical adhesive plaster as well
1639634201966.png

1639634378083.png
 

Sjvalleydave

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Feb 16, 2023
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Caruthers. CA
[size=+3]Rewrapping a battery[/size]

View attachment 21149

The above battery cannot be used anymore, it will short and might explode.
The wrapping will sometimes break, luckily it is a fairly simple operation to fix it.



[size=+2]Tools and parts needed[/size]

View attachment 21150

I am using shrink wrap to repair the battery, due to the heat gun I uses, I have selected a low temperature type.
When flat it is 29.5 mm wide, the inner diameter is 18.5 mm, it will shrink at 80 Deg. C.
I bought a roll with 25 feet (7.6 meter) on ebay for $11 (Sellers name is atop_authentic_auction). This roll will last for more than 80 batteries. Fasttech has heat shrink in 1 meter pieces for less than $1.
This heatshrink is also fairly thin, this is an advantage for some lights.
Often heat shrink is specified in width of the flat tube, the table below shows the minimum sizes for different battery sizes.
View attachment 21151

View attachment 21152

As a heat gun I uses a hair dryer, it is not the perfect tool for the job, but it can be used.

View attachment 21153

I do also need something to measure with, my digital caliper is fine for that (A ordinary ruler could also be used).
With a caliper, remember to cover the jaws or it will short the battery.

View attachment 21154

To cut the heat shrink I uses scissors.



[size=+2]Rewrapping[/size]

View attachment 21155

I want the heat shrink tube to be about 3 mm longer than the battery at both ends, with a 68 mm battery this means 74 mm tube.

View attachment 21156

The new tube for the battery has been cut of the roll.

View attachment 21157

I uses the fingers to removing the old heat shrink, using a knife or scissors is unsafe.
If there is two layers of heat shrink, only remove the outer layer.

View attachment 21158

The "naked" battery, do not try to bend the protection pcb out to get a look.

View attachment 21159

Putting the new heat shrink onto the battery.

View attachment 21160

There will be about 3 mm extra at each end.

View attachment 21161 View attachment 21162

Applying heat, rotate the battery and swipe the heat gun back and forth. If using a real heat gun, be careful with the fingers holding the battery!
It is possible to increase the temperature by covering part of the air intake on the heat gun (This might also melt the gun if overdone).
The battery must not be heated much (As long as it is possible to hold it, the temperature is fine). This is usual not a problem, the heat shrink will shrink long time before the battery is heated.



[size=+2]Final result[/size]

View attachment 21163 View attachment 21164

View attachment 21165

View attachment 21166

With a new covering, the capacity information is gone, to fix that I have added a label with capacity. I also included the date I got the battery.
[size=+3]Rewrapping a battery[/size]

View attachment 21149

The above battery cannot be used anymore, it will short and might explode.
The wrapping will sometimes break, luckily it is a fairly simple operation to fix it.



[size=+2]Tools and parts needed[/size]

View attachment 21150

I am using shrink wrap to repair the battery, due to the heat gun I uses, I have selected a low temperature type.
When flat it is 29.5 mm wide, the inner diameter is 18.5 mm, it will shrink at 80 Deg. C.
I bought a roll with 25 feet (7.6 meter) on ebay for $11 (Sellers name is atop_authentic_auction). This roll will last for more than 80 batteries. Fasttech has heat shrink in 1 meter pieces for less than $1.
This heatshrink is also fairly thin, this is an advantage for some lights.
Often heat shrink is specified in width of the flat tube, the table below shows the minimum sizes for different battery sizes.
View attachment 21151

View attachment 21152

As a heat gun I uses a hair dryer, it is not the perfect tool for the job, but it can be used.

View attachment 21153

I do also need something to measure with, my digital caliper is fine for that (A ordinary ruler could also be used).
With a caliper, remember to cover the jaws or it will short the battery.

View attachment 21154

To cut the heat shrink I uses scissors.



[size=+2]Rewrapping[/size]

View attachment 21155

I want the heat shrink tube to be about 3 mm longer than the battery at both ends, with a 68 mm battery this means 74 mm tube.

View attachment 21156

The new tube for the battery has been cut of the roll.

View attachment 21157

I uses the fingers to removing the old heat shrink, using a knife or scissors is unsafe.
If there is two layers of heat shrink, only remove the outer layer.

View attachment 21158

The "naked" battery, do not try to bend the protection pcb out to get a look.

View attachment 21159

Putting the new heat shrink onto the battery.

View attachment 21160

There will be about 3 mm extra at each end.

View attachment 21161 View attachment 21162

Applying heat, rotate the battery and swipe the heat gun back and forth. If using a real heat gun, be careful with the fingers holding the battery!
It is possible to increase the temperature by covering part of the air intake on the heat gun (This might also melt the gun if overdone).
The battery must not be heated much (As long as it is possible to hold it, the temperature is fine). This is usual not a problem, the heat shrink will shrink long time before the battery is heated.



[size=+2]Final result[/size]

View attachment 21163 View attachment 21164

View attachment 21165

View attachment 21166

With a new covering, the capacity information is gone, to fix that I have added a label with capacity. I also included the date I got the battery.
If you are going to go to the trouble to re wrap the battery, before you shrink the wrap, put a new insulator at the positive end. You get 100 black or white for like $1...
 

Sjvalleydave

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Joined
Feb 16, 2023
Messages
32
Location
Caruthers. CA
I bought some pre cut heat shrink a few months ago and now I am almost out of it. I cannot find anyone anywhere selling pre cut pieces. Anyone out there have a supplier? Sorry for posting on this thread but it seemed like an appropriate place.
There a lot of places. Liion Wholesale, The 18650 Store. AliExpress, Ali Baba, etc
 

Sjvalleydave

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Joined
Feb 16, 2023
Messages
32
Location
Caruthers. CA
I rechecked the pricing. Black or white insulators 5 for .25 cents. Pre cut shrink wrap, clear, black, white,orange, green, red, blue, yellow, bright yellow, etc, etc....also transparent purple, green, blue, yellow, etc..10 for 98 cents...
 

chaosdsm

Enlightened
Joined
Feb 11, 2014
Messages
273
Location
Florida
For the most part, there's no need to replace the insulator, they do not wear out within the lifespan of a battery. It's good to have spares on hand, but not needed with every re-wrap unless of course the original insulator was damaged along with the original shrink wrap, and you were lucky enough not to have the battery shorted at time of the damage.

Precut are definitely more convenient, but they're also considerably more expensive vs bulk wrap, I recently purchased 500 yards of clear 200 gauge (0.002"/2mil) 1.5" diameter 2:1 for about $48 shipped, that's just 3 cents per foot or less than 1 cent per battery & covers all cells 17mm to 36mm diameter. I may never use it all, but I do shrink wrap all dead cells and add felt insulator pads to both ends before sending them for recycle. You can get much thicker 2:1 polyolefin heatshrink 1.5" diameter for about $0.60 - $1 per foot depending on size of the roll you buy and if you get thin or thick gauge. 1" is even cheaper if you're only doing 14mm - 22mm diameter cells.

Also need to be careful buying precut wraps... some of the cheap pre-cuts can vary by about 2mm-3mm in length which can be problematic if they're 3mm short.
 
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