Become a Patron!

How to Rewrap an 18650

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
FAQ UPDATED: 5 May 16

Rewrap 1 Heat Gun and Wraps.jpg

Rewrap 2 72mm and Peeled Wrap.jpg

Rewrap 3 Sleeve 4mm Each Side.jpg

Rewrap 4 Top and Bottom.jpg

FAQ
Q: My wraps shipped flat, with two creases. Is that going to be an issue? Should I panic?
A: No.

Q: How fast does the wrap shrink onto the batt?
A: Almost instantly, once you apply heat. Remove from heat immediately, once the wrap looks pretty.

Q: Does the wrap really shrink perfectly around the edges like that?
A: Yes. It's awesome.

Q: You say I need wrap with a length of 72 mm. What if I buy a roll of wrap? Do I need to cut it?
A: You're an idiot.

Q: How wide are the typical wraps?
A: Shipped/flat width is 30 mm.

Q: What if I lose my round insert/grommet thingy from the positive terminal?
A: Cry. Or buy some insulators. Or make some insulators. Or don't lose your insulators in the first place.

Q: Why do I need to write on the battery before I put the wrap on it?
A: You don't. You can write on the outside of the wrap instead, but it might wear off. If you want to ask about pairing/marrying batteries, there are other threads for that.

Q: Can I put a full wrap over another full wrap?
A: Don't put a full wrap over a damaged wrap, because that would make you an idiot. Technically, a wrapped battery will fit in a shrink-wrapped sleeve. So yes, you can technically double-wrap. But remember... if you're dropping your double-wrapped battery in a circular battery compartment, it might get stuck. If you're paranoid about losing the dot-matrix info from your original wrap, just take a pic of it before you throw it away.

Q: That white sticker has to be important. You say it's worthless. I would like permission to panic.
A: When batteries leave Asia by air, they need stickers because there are dumb regulations. The manufacturers or master distributors are like "regulations shmegulations, we don't care." So a third party throws the stickers on, using cheap labor. Sometimes you'll get a sticker that's accurate, sometimes you won't. Even legit Samsung/LG/Sony batts can have inaccurate white labels. It happens. Don't panic.

Q: Why do I need a wrap at all?
A: To keep from shorting things and blowing yourself up. I'd explain the battery terminals of the 18650's, but someone will just come along and write it better. So just wrap your damn batteries.

Q: Can you do me a favor and heat up a wrap without a battery in it? I just want to see what it looks like.
A: Sure.


Rewrap 5 Shrink No Battery.jpg


Q: I hate metric. What are the inch measurements of wraps?
A: Measurements for the most common sleeve:
Length = 72mm = 2 13/16 inches
Width, uncut/flat = 30mm = 1 3/16 inches


Q: I have some protected batteries sitting around. But pre-cut wraps are too short. What do I do?
A: Buy a roll. Get your battery measurement and add 8mm (or 5/16 inch). Cut that length. Done.

Q: The wraps I just bought are not close to the correct size. What do I do?
A: If they’re too long, cut them. If they’re too wide, you might have purchased the wrong ones, or they sold you the wrong ones by mistake. There are a ton of different battery wrap sizes and thicknesses available for all different single batteries and DIY packs.

Q: I was using a metal caliper to measure the battery and things went wrong. What happened?
A: Stupidity happened. Essentially, you turned your caliper into a coil. Moron.
 
Last edited:

riverdan

VU Donator
Bronze Contributor
Member For 4 Years
Member For 3 Years
Member For 2 Years
Member For 1 Year
Awesome post, have some wraps on the way.

One thing

Q: You say I need wrap with a length of 72 mm. What if I buy a roll of wrap? Do I need to cut it?
A: You're an idiot

Where can I find wrap snips?
 

AndriaD

Yes, I DO wear a mask! I'm vaccinated, too!
VU Donator
Diamond Contributor
ECF Refugee
Member For 5 Years
Thx for this! The wrapping on one of my 25R's got scored almost the first time I used it, so since then, I haven't used it -- now I feel I might actually be able to handle re-wrapping it.

Thx!
Andria
 

vap3r

Bronze Contributor
Member For 4 Years
Member For 3 Years
Member For 2 Years
Member For 1 Year
Not a fan of clear transparent wraps used without an insert. It is very difficult to discern tears, nicks and gouges at a glance against the steel of the battery can. Even silver wraps provide a superior contrast versus clear transparent. Representing Raider Nation...

rewrapped_batteries.jpg
 

vap3r

Bronze Contributor
Member For 4 Years
Member For 3 Years
Member For 2 Years
Member For 1 Year
For 0.08mm PVC wraps, 75-80C is a good temperature to shrink at. Not too fast and not too slow, even heating is the name of the game.

makita_heat_gun_battery_wraps.jpg
 

conanthewarrior

Gold Contributor
Member For 4 Years
Good guide. It will be very helpful for a lot of people.

Out of my 32 18650's, a lot have been re wrapped, due to small tears ETC. I use a hairdryer, and it literally takes seconds for the wrap to take to the battery.

For the price of a roll of shrink wrap for 18650's, it is definitely worth it for saving your batteries, and above all, safety. Sure, you can patch your batteries, but I much rather rewrap than patch with some electrical tape that may fall off as you insert the battery, without your knowledge. This is bad enough with a regulated mod, but if you are using a mech, you really want a safely wrapped battery.

Well done on the guide :).
 

zaroba

Gold Contributor
Member For 5 Years
A heat gun or hair dryer?

Darn, I don't have either so I used one of the burners on my gas stove :p
Pretty easy actually, just wave it slowly back and forth a couple inches over the flame, the wrap shrinks and the battery doesn't have enough time to warm up the slightest bit. Your fingers will burn before the wrap does unless your doing something dumb like holding the battery directly in the flame.

IMG_1790.JPG
 

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
We went over the kitchen-heat-source thing in another thread a while ago. We were hypothesizing about using an oven, preheating it just a bit, putting the batt in temporarily, and pulling it back out right away. Although the discussion came across as reckless. Oops.

I did try using a tiny butane torch, which burns hotter than natural gas. Tried it on a wrap with no battery. The wrap didn't shrink. It just caught fire. Flames and stench.

There are other shrink wraps with higher heat tolerances which you can use a torch for. That black tubing for electrical wire. I've seen car audio installers use that method.
 

zaroba

Gold Contributor
Member For 5 Years
My kitchen stove is propane (and my furnace and hot water heater).
But I doubt that makes a difference when it comes to large appliances and food heating applications.

Wraps were from illumn if that makes a difference.

It was my first time doing a rewrap and my batteries were well beyond needing it (started to have issues with the insulator slipping out of the torn wraps). Love the clear wraps though. Tossed a sticker on each battery before wrapping it with the battery type, marriage numbers/letters, and the date that I bought the battery so I'd know how old they are. Might just do it right away in the future when I buy new batteries. Sure beats dealing with a permanent marker and having the lettering/numbers wear off.
 

Markw4mms

#Team Jimi Supporter
VU Donator
Diamond Contributor
Member For 4 Years
ECF Refugee
Thanks for sharing! I so need to get a few of mine rewrapped.
 

AlbyKortoona

VU Donator
Gold Contributor
Member For 4 Years
Member For 3 Years
ECF Refugee
I'm already married, wouldn't it be against the law to marry my battery?

And how can I get those custom arcing pits on the negative end of my battery so it can vent there if it overheats? :p
 

SuperflyTNT

Member For 3 Years
Member For 2 Years
Member For 1 Year
My kitchen stove is propane (and my furnace and hot water heater).
But I doubt that makes a difference when it comes to large appliances and food heating applications.

Wraps were from illumn if that makes a difference.

It was my first time doing a rewrap and my batteries were well beyond needing it (started to have issues with the insulator slipping out of the torn wraps). Love the clear wraps though. Tossed a sticker on each battery before wrapping it with the battery type, marriage numbers/letters, and the date that I bought the battery so I'd know how old they are. Might just do it right away in the future when I buy new batteries. Sure beats dealing with a permanent marker and having the lettering/numbers wear off.

I like to apply scotch tape over the marker, is that a bad idea?
 

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
I like to apply scotch tape over the marker, is that a bad idea?

So it's bare batt --> marker --> scotch tape --> wrap ?
If that's the case, the scotch tape isn't a bad idea... it's just not necessary.

If it's bare batt --> wrap --> marker --> scotch tape...
Considering so many batts we get have that fake shipping sticker on the outside, it can't be any worse.

Personally, now that I've had
1. Something peel off and get stuck in a battery compartment and
2. An entire battery get stuck in a mod,
I'm wrap-only. But that's just me.
 

zaroba

Gold Contributor
Member For 5 Years
I don't see why tape wouldn't work.
I've never used it though, always figured it would peel and be a hassle.
 

JERUS

Gold Contributor
Member For 4 Years
Member For 3 Years
Member For 2 Years
Member For 1 Year
We went over the kitchen-heat-source thing in another thread a while ago. We were hypothesizing about using an oven, preheating it just a bit, putting the batt in temporarily, and pulling it back out right away. Although the discussion came across as reckless. Oops.

I did try using a tiny butane torch, which burns hotter than natural gas. Tried it on a wrap with no battery. The wrap didn't shrink. It just caught fire. Flames and stench.

There are other shrink wraps with higher heat tolerances which you can use a torch for. That black tubing for electrical wire. I've seen car audio installers use that method.
I ended up using a BIC lighter because I didn't want to wait for my roommate to get home to see if they had a hairdryer, and I didn't want to buy one to use so rarely. Held the battery 4-6 inches above the flame, rotated the positive side to get that in place then just went down the battery rotating it as I did. I only had one screw up, the wrap split where the indent is on the side wall towards the positive end. Ripped it off and redid it, 8 batteries now re-wrapped nicely.

It was surprising how little heat was necessary, it was hot but I could put my fingers in the hot air that was shrinking the wraps. Leaving it there would get painful but it wasn't too bad. Now my thumb that was holding the lighter down, that got a little scorched, reminding me of the old days.
 

SuperflyTNT

Member For 3 Years
Member For 2 Years
Member For 1 Year
So it's bare batt --> marker --> scotch tape --> wrap ?
If that's the case, the scotch tape isn't a bad idea... it's just not necessary.

If it's bare batt --> wrap --> marker --> scotch tape...
Considering so many batts we get have that fake shipping sticker on the outside, it can't be any worse.

Personally, now that I've had
1. Something peel off and get stuck in a battery compartment and
2. An entire battery get stuck in a mod,
I'm wrap-only. But that's just me.

Thx for the response... I'm definitely getting wraps now , way to many batteries with nicks I don't use. Never realized how easy they are to replace.
 

JERUS

Gold Contributor
Member For 4 Years
Member For 3 Years
Member For 2 Years
Member For 1 Year
Thx for the response... I'm definitely getting wraps now , way to many batteries with nicks I don't use. Never realized how easy they are to replace.
Super easy, super cheap, super fast, and make them look all spiffy.
 

JERUS

Gold Contributor
Member For 4 Years
Member For 3 Years
Member For 2 Years
Member For 1 Year
:idea: I need to get some copper colored ones and black.
 

cloudsbroclouds

Member For 3 Years
Member For 2 Years
Member For 1 Year
ECF Refugee
dont forget to use self adhesive insulators to keep them from blowing away! a lot thicker and stronger than the paper ones most manufacturers use.
 

AmandaD

Platinum Contributor
Member For 4 Years
I've wrapped batteries with the wrap from FT, but this time I have wrap from http://battwrap.com/ They're absolutely impossible - very thick, and I've already been through 3 trying to get one battery wrapped with both ends evenly covered. I give up LOL I've never had a problem before, but this time I'm stumped:cuss2:
 

AmandaD

Platinum Contributor
Member For 4 Years
Hmm, just realized the problem when I got out my roll of FT wrap - these new ones are way too big....must be the wrong ones :-(
 

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
these new ones are way too big

What are the length and width measurements of the purple wraps? Just curious.

Battwrap.com sells their pre-cut wraps a little long. They don't post the exact measurement, but I'm guessing 74 or 75mm.
 

AmandaD

Platinum Contributor
Member For 4 Years
What are the length and width measurements of the purple wraps? Just curious.

Battwrap.com sells their pre-cut wraps a little long. They don't post the exact measurement, but I'm guessing 74 or 75mm.
They look like they'd fit a 26650 - hold on I have to find something to measure with. I'm fairly sure these were cut way too wide!
 

AmandaD

Platinum Contributor
Member For 4 Years
71mm long x 38mm wide - no wonder the stupid things don't fit. My roll of FT is 26mm wide LOL. This is definitely a messed up wrap LOL
 

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
38mm? You got that from BattWrap?

For the 26mm... FT has two measurements for those rolls. 26mm diameter and 31mm width. Those numbers don't jibe together, but...

Either way, the diameter and width measurements will be different. Example: FT's 30mm precut wraps have a circular diameter of around 20mm.

Nerd Alert
It should all work out using diameter and pi calculations. The wrap width should be approx (d*pi)/2.
 

AmandaD

Platinum Contributor
Member For 4 Years
38mm? You got that from BattWrap?

For the 26mm... FT has two measurements for those rolls. 26mm diameter and 31mm width. Those numbers don't jibe together, but...

Either way, the diameter and width measurements will be different. Example: FT's 30mm precut wraps have a circular diameter of around 20mm.

Nerd Alert
It should all work out using diameter and pi calculations. The wrap width should be approx (d*pi)/2.
LOL I did check with Battwrap, and they assured me the new ones would be the right size.
 

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
I did check with Battwrap, and they assured me the new ones would be the right size.

They sell products for a single thing: 18650s.
Would love to know how something like that slipped by them.

Oh, and why don't they sell rolls? Sad.
 

AmandaD

Platinum Contributor
Member For 4 Years
They sell products for a single thing: 18650s.
Would love to know how something like that slipped by them.

Oh, and why don't they sell rolls? Sad.
Yes I double checked that the wrong ones hadn't been ordered - but, as you say, they don't sell them. The guy from the website did acknowledge these were the wrong size though - probably some new person cutting them LOL
 

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
Yes I double checked that the wrong ones hadn't been ordered - but, as you say, they don't sell them. The guy from the website did acknowledge these were the wrong size though - probably some new person cutting them LOL

I found out what wrap you got by mistake, but can't find the link at the moment. They use it for C batteries and some packs. Crazy thick. Sold by the spool.
 

Robert B

Gold Contributor
Member For 4 Years
If you want to create a button-top out of a flat-top:

Buy some of these 9.5mm caps. 50 for a dollar.
Buy some of these sticky back cardboard insulators. 100 for a $1.35
Buy some of these clear pre-cut wraps. 50 for a $1.46. (these are the slightly thicker mil wraps)

Set a cap on top of the flat-top (you can dab a small drop of super glue if you want. I don't)
Stick on an insulator on top of the whole thing
Slide a clear wrap on and shrink it.

Instant Button-top

wrap parts.jpg

Button.jpg

button sticker.jpg

button shrink.jpg
 

Lost

Silver Contributor
Member For 4 Years
Member For 3 Years
If anyone currently has a wonky battery wrap and wants to try rewrapping...

I have four clear 18650 wraps in a stamped business envelope ready to go.

Reply here, then PM me a U.S. address or P.O. box.

(Can't do international shipping right now. Sorry.)
 

AndriaD

Yes, I DO wear a mask! I'm vaccinated, too!
VU Donator
Diamond Contributor
ECF Refugee
Member For 5 Years
If anyone currently has a wonky battery wrap and wants to try rewrapping...

I have four clear 18650 wraps in a stamped business envelope ready to go.

Reply here, then PM me a U.S. address or P.O. box.

(Can't do international shipping right now. Sorry.)

Ooooh ooooh me me! (I feel like Horshack). Got a nice almost new Samsung that got scored the first time I used it, been meaning to order some wraps but there's always so much else I need.

Andria
 

conanthewarrior

Gold Contributor
Member For 4 Years
I keep seeing custom printed 18650 wraps. Where are these coming from? I'm a sucker for unnecessary swag.
Most likely China. I've seen them on the China sites, a pack of 100 is about $9, the ones with the things like superhero's on etc.

If you mean actual custom prints, with peoples names for example, I have seen guides where people simply print off their design onto paper, and use a clear wrap so it shows through.

EDIT: here is a quick guide if you wanted to make your own :) https://www.imrbatteries.com/blog/make-your-own-custom-battery-wraps/

It is quite likely though you could order custom wraps from many places if you wanted enough of them made too.
 

jamezcua12

Member For 3 Years
Member For 2 Years
I just rewaped my 18650 batterys and I noticed some sticky black stuff/goo on the bottom and top of my 18650. They hold and change just fine .. can someone please help me? And let me know what it is or if it's safe to use

Sent from my SM-G920T using Tapatalk
 

Zamazam

Evil Vulcan's do it with Logic
VU Donator
Platinum Contributor
Member For 5 Years
I just rewaped my 18650 batterys and I noticed some sticky black stuff/goo on the bottom and top of my 18650. They hold and change just fine .. can someone please help me? And let me know what it is or if it's safe to use

Sent from my SM-G920T using Tapatalk
that sticky black goo is the electrolyte. Stop using them immediately, they are leaking. Recycle them. Don't use them.
 

AndriaD

Yes, I DO wear a mask! I'm vaccinated, too!
VU Donator
Diamond Contributor
ECF Refugee
Member For 5 Years
And recycling is by far a better idea that just "throwing them out" -- you don't want those chemicals ending up in a landfill. Radio Shacks, Home Depots, and maybe also Lowes, have battery recycling bins, right by the doors.

Andria
 

VU Sponsors

Top