Introduction: Simple, Cheap, Cool, Waterproof and Gummy Diy Battery Holder

Picture of Simple, Cheap, Cool, Waterproof and Gummy Diy Battery Holder

I know how many of you inventors have desired a versatile battery holder to power your projects, I know you can't sleep without that... so this strange accessory has born ;-)
This gadget has a simple function, keep a battery inside, and yes you could buy an ordinary plastic black and impersonal battery holder if you want, but keep in mind that this is coloured (you can choose the Sugru colour that you prefere), rubbery and even water resistant (although you can't dive with it...).

Step 1: The Actors

Picture of The Actors

I made it for Li-ion 18650 batteries, because they're very powerful and really versatile for electronic projects, but you can build the same gadget for one or more batteries of any type, voltage and shape.
I've used some metal washers to make contacts, maybe copper pieces should have been better because copper is more conductive... I'll let you know after some test.

Step 2: The Roles

Picture of The Roles

To choose the right washers you have to give a look to these two images. As you notice the fat washer can't make contact with the negative side of the battery, so we'll use it for the positive terminal. Same matter for the thin one, theoretically it shouldn't touch the positive tip so we'll keep it for negative flat side. Pay attention to avoid any shortcut when working with powerful rechargeable cells, it could be danger and damage your batteries.

Step 3: The Teams

Picture of The Teams

Let's melt some tin on the washers. Probably you should find it very arduous because tin doesn't stick on the steel of the washers, in that case it's essential spread some flux on them.

Step 4: The Bands

Picture of The Bands

Now you can choose some good quality natural rubber bands (better with flat sides, not as mine), the more they're tense on the batteries, the more they'll keep the contacts connected. You can try with only one band for each battery if it's enough strong.

Step 5: The Bond

Picture of The Bond

To keep the bands in place meanwhile you work on the batteries ends, wrap them with some tape pieces.
I've covered the battery ends with some silicon grease, to avoid the caps attaching to the batteries surface, but I'm not sure it's the best material, it worked not very well... maybe some oil is better? Some Sugru guru certainly has the answer.

Step 6: The Helpers

Picture of The Helpers

Now the best material to wrap the washers and keep them over the batteries ends it's the Sugru, because it dry fast and it has all the colours you want, you can indeed mix the basic colours to make the full rainbow! Another solution could be the two elements silicon which I've used to make the remote control plug, but it's ugly pink!
We choose obviously black and red packets from the five colours of the set, we don't need to mix this time.

Step 7: The Wrap and the Split

Picture of The Wrap and the Split

Now cut in half each packet's content, stir it in your hands and cover the washers on the right sides of the batteries.
Then push it around the cilynders, and over the washers so that it will englobe them. Finish off the external surface of the Sugru (maybe better than I've done), and hung them up to avoid leaving a flat print while they dry. 
After some time (maybe one hour to be sure?) you can pull the two caps away from the batteries and clean them.

Step 8: The Goal!

Picture of The Goal!

It's all! You have now two new battery holders which could be useful to power some little electronic project, or maybe your phone or your digital camera too (usually cellphone and cameras li-ion batteries have one cell, so the same voltage of 3.7V 18650 stilo), all with some dedicated plugs to connect at the wires ends.


deswiger (author)2016-07-20

Very nice. I really do think this has a few different applications for me. BUT, can you be sure of "water proof" or just "water resistant"? I'm thinking submarine stuff. This stuff is a bit expensive to leave left-overs laying around.


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JustinO25 (author)2016-02-29

Hi, ! slight problem with the design, and you should put a safety warning with this. Should there be any problem with the batteries over draining, Li-ion batteries need to be able to vent out of the positive terminal. This design could prevent the battery from venting if this should happen. I plan on using it however, after the sugru sets, I'm going to cut a whole in the top of the positive terminal.

andrea biffi (author)JustinO252016-02-29

this is really interesting... thanks for the information

PetrichorXFi (author)2015-07-05

Nice idea, one serious issue. Rubber bands like that dry out and crack. You should use some other stretchy material, perhaps bike inner-tubes? They have same issue as rubber bands but less often. Downside is they do have have as much stretch.

g00dhum0r (author)2013-05-22

Nice, so if I make this and use a usb on the wire end, I can charge my cell phone with 1 double A battery?

leaf26 (author)g00dhum0r2014-05-12

usb is 5V, so keep that in mind

LanceB2 (author)leaf262015-02-15

stock iphone usb wall chargers put out 3.7v. Perfect.

Kinnishian (author)LanceB22015-06-05

for the record, this is not correct in the slightest. 5.0V is what they put out. The regulation for the battery is inside the phone, the USB charger is USB standard voltage (some exceptions can apply, and there is some logic communication I'm aware of, some of it just through resistors on the data lines setting the current mAh desires.)

kuman245. (author)2014-10-19


Nice idea but 18650 and the likes have safety vent hole at its positive terminal to prevent explosion due to build up pressure in case of high charging or draining, it is not good to cover those holes shut.


kmargie25 (author)2014-08-03


DragonDon (author)2013-10-13

I'm surprised the Sugru didn’t' stick to the batteries. Cool stuff.

andrea biffi (author)DragonDon2013-10-13

I've covered the battery ends with some silicon grease, but I suggest to try with oil too...

jcduplessis (author)2013-06-06

Great idea! Can see myself using these in future projects, thanks!

iPodGuy (author)2013-05-11

This is awesome.

projectsugru (author)2013-04-12

lovely, looking forward to seeing these in your tests :)

I've used it to power the gigapixel panorama head, it works great, but I needed to add an addictional external stronger tape from a bike tube to keep the contacts tight..

lindarose92 (author)2013-05-04

Complimenti finalista!!! :)

andrea biffi (author)lindarose922013-05-04

ahah I hope Mac Gyver would be proud of me!

PirateLabs (author)2013-04-29

Very well done. I like the colors idea as well. I usually just make some universal battery holders by soldering the leads to two small neos. This way, i can use any size battery...AAA, AA, D, C, etc. They hold well and work great...but do not look as cool as yours.

isacco (author)2013-04-19

Complimenti per il tuo instructable!
Congratulations for this instructable. The design is excellent, whatever the material one uses (Sugru and rubber band type) for crafting.

Aik68 (author)2013-04-17

Nice!! I did a similar solution but instead of using rubber bands I used plastic tie wraps and water bottle caps, you can see it at:

andrea biffi (author)Aik682013-04-19

that's very interesting, I've always been searching good re-use of plastic bottle caps. Also your other little battery holder is great!

gutinga (author)2013-04-17

eccezzionale, eccellente idea, complimenti (IT).
wonderful idea!

ryebreadz (author)2013-04-16

this is a cool idea, but my concern is with how long those rubber bands will last 1, 2 years?

Mic100 (author)2013-04-14

very interessant
is it realy waterpropf after rechargin 10 times ?

andrea biffi (author)Mic1002013-04-15

as 2nup350 pointed out this holder is not properly waterproof, it water resistant, so it means that you can sprinkle water on it, but you can't immerse it.
I don't understand what do you mean about recharging...

Mic100 (author)andrea biffi2013-04-15

agree it is always interesting
after 10 refills I think that each recharge must remove the battery
to put it in the charger and put it back in its holder
I am French and at home there is no sugru is what remains flexible
when it becomes stiff or hard as epoxy resin ?

skuishingbugs (author)2013-04-15

this is awesome!

tortoise1 (author)2013-04-14

I need to make a multi cell holder and need to know how much sugru it takes to make 1 holder

andrea biffi (author)tortoise12013-04-15

I've used entirely the two little packets in photo, so it's 5 g for each holder.

rayd888 (author)2013-04-14

Great idea! Thanks for posting.

8steve88 (author)2013-04-14

Great idea.

konstantinosnk (author)2013-04-14

clever.Good Idea

kishida (author)2013-04-14

Nice battery holders.
Instead of using the common rubber band, you should try making your own rubber bands from bicycle inner tubes, because they don't degrade as quickly as the common rubber band.

kishida (author)kishida2013-04-14

whoops, there already was a suggestion to use bicycle inner tube rubber for the bands.

andrea biffi (author)kishida2013-04-14

no problem, it's a good suggestion!

profpat (author)2013-04-13

very well done, only problem, we still do not have sugru here in the still third world..

andrea biffi (author)profpat2013-04-14

Buy Sugru online, I think they ship to Philippine too...

streetrod5 (author)2013-04-13

Great idea! I use the Ultrafire batteries in my very bright flashlight, and they are very good. I also enjoy all the 360 Cities photography on your website - it's beautiful.

andrea biffi (author)streetrod52013-04-14


verence (author)2013-04-13

Clever solution for odd sized batteries or times when you run out of battery holders.

Copper might be more conductive, but that wouldn't make a big difference, as the washers are short (in length) and thick (i.e. compared to the wires), so you might get 15 MilliOhm instead of 17 MilliOhm for the washer. But copper will corode (green copper) and that (the oxide layer) will be a problem as it is a very bad conductor. Stay with your washers.

andrea biffi (author)verence2013-04-13

Thanks for the analysis, very accurate, I'll stay with them :-)

Gordyh (author)andrea biffi2013-04-14

For long term use of the steel washers, May I recommend that you Tin the whole washer with solder to keep it from rusting. Same goes for copper. Also wondering about the electrical properties of stainless steel washers?

frank26080115 (author)2013-04-12

Can Sugru really be used for dental implants?

LOL just thought that was a funny ad placement

Now we have some uses for all these Canadian pennies

JAJA you almost made me fool!
Canadian penny are copper, right?

85rocco (author)andrea biffi2013-04-14

No, the most recent Canadian pennies are copper plated steel, they replaced copper plated zinc pennies, you need to go back before the mid nineties to find pennies that were mostly (98%) copper.

agis68 (author)2013-04-14

very good!!!! but sugru is still so expensive!!!!

ke6rim (author)2013-04-13

Hi ... Merely a recommendation. Please be careful when working with rechargeable type batteries, they need to vent when their being charged and when being used under heavy discharge rates. Lastly, ensure that the washer doesn't cause a direct short between the Positive and Negitive terminals. Great idea, keep up the good work. Richard T

andrea biffi (author)ke6rim2013-04-13

Yes, Lithium cells are powerful and it's better pay much attention to avoid shortcuts, I might add a warning in the instructable...

ke6rim (author)andrea biffi2013-04-13

Thank you, were thinking along the same lines. Always Safety First. "Happy experimenting"

About This Instructable




Bio: I'm an Italian freelance structural engineer, graphic designer and photographer, and I'm teaching physics in Waldorf schools. I always investigate electronics, robotics and ... More »
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