Introduction: Soldering Directly Onto a Battery

Picture of Soldering Directly Onto a Battery

In my first instructable I needed to use an AA Battery to plate some copper onto a quarter, and I ran into an issue. I didn't have a battery holder, and I was too cheap to go out and buy one. So I scoured the internet looking for ways to solder a wire directly onto a battery and found nothing except that a tin strip could be welded onto a battery.

Like most people I don't have a welder so I started experimenting with using flux and other various agents until i finally found that filing the end of the battery would allow solder to pool. then I could solder a wire onto it easily.

This technique can be used for both normal and rechargeable batteries, so if you need to replace some rechargeable batteries in battery packs like the one from the Xbox 360 you can now do it. I also used it when making this instructable

 Comments are welcome and appreciated

Step 1: Materials

Picture of Materials

What ya need der:

-A Soldering iron

-Some rosin core solder

-A file

-Two pieces of wire preferably red and black to avoid confusion

-The battery

-Wire Strippers(not shown, but still needed)

-Some Skill with Soldering

Step 2: Filing the Terminals

Picture of Filing the Terminals

Take a file to the positive and negative ends of the battery and rough them up. make sure the whole surface of the battery terminal is evenly rough. its OK if you mess up the covering a little bit.

Step 3: Applying the Solder

Picture of Applying the Solder

Make sure your soldering iron is clean and then tin the tip of it. Secure the battery in a vice or clamp or something and make sure your iron is hot and ready. Using the iron heat up the terminal of the battery and apply solder, you don't have to heat the battery terminal all the way up to solder melting temperature, you can just use the iron to melt the solder. The solder should pool on the terminal, if it doesnt you need to rough it  up more, and try again.

Step 4: Attaching the Wires

Picture of Attaching the Wires

Strip both ends of each wire and then tin one end of each wire. Use the iron to heat up the solder on the terminal and insert the tinned end of the wire into the solder pool. FYI red wire is positive, black wire is for negative, common, or ground. and thats it. It may not be the simplest way of utilizing a battery, but you cant get much cheaper.


ozzyp3 (author)2017-02-23

what happens if i solder it to a 9v battery

Barkuti (author)2017-01-29

Interesting. This has piqued my interest in this stuff. I am getting a new soldering iron, and may get to solder some 26650 cells.

Was making up my mind between a Bakon 950D and a CXG DS110T, guess I'm going to lean towards the DS110T 110W unit; ought to help.

seanhelmi (author)2016-10-03

sorry in my comment I said "resin" I meant "rosin". Anyway use flux-free solder and do not use the separate flux.

seanhelmi (author)2016-10-03

Very helpful. I would suggest a small follow up to make this process even easier: 1. File the battery ends a bit with a metal file or sandpaper. This helps the solder adhere. Just a little filing/sanding is enough, just take off a little bit of the shine. Batteries have very smooth/shiny ends for good contact and solder has a tendency to slide off without filing/sanding. If you are using shiny leads then file/sand them as well. 2. Use resin-free solder aka flux-free solder (the kind where the resin/flux comes in a separate bottle in the solder package). Sometimes called "silver solder". The resin/flux causes the solder to slide off the battery and also can blacken the battery reducing conductivity.

Shirogane (author)2015-02-21

Is it safe to do this with 9V PP3 batteries? It's for a simple door alarm and obviously I will need to desolder and replace eventualy.

PaulY5 (author)Shirogane2015-10-25

I would just use a 9v snap on connector. Find an old smoke detector or other outdated radio and rip it out. Or, just go buy one.

ErikT2 (author)PaulY52016-06-19

Pull apart a dead 9v...pull off the terminals and reuse them as a snap connector...there are ibles about how to do this.

whayden (author)2013-08-18

Any reason that copper/conductive tape would also work?

I'm no good at soldering is why I ask.

TheWDMC. (author)whayden2016-05-23

Not as sturdy, but still should work

tkalfaoglu (author)2015-09-17

how hot does the solder need to be?

Too hot, it would boil the battery, too cold, it won't work..

liam.plybon.3 (author)2015-06-21

I was curious if this could even be done, and you did not disappoint! Great ible!

ArticAkita (author)2015-02-08

How cool! What a truly helpful instructable! you did a awesome job! Nice copper plating bit on the quarter too!

ugur23 (author)2014-04-22

careful about coin batteryies . i have exploded one unfortunately.

but works with a123,nimh (dont heat so much) and 18650 cells. but dont try on flat li ion cells. i have puffed one when soldering. but lipo has external terminals and they safe

whayden (author)2013-08-18

Any reason not to use some copper/conductive tape?

Encik_Google (author)2012-09-21

I try it to my battery but it not hold to strong.its not working

park47 (author)2011-08-13

I like this ,will try...Thanks..

And..I like .. Phil B says: too :)
" The people who make the most unkind comments are those who have published no Instructables and think they are experts on everything. It all looks a lot different when you have published something of yourself for others to comment upon it. Do not be discouraged."

ikssk (author)2011-05-13

Great instructable. I've been soldering on to batteries for years, mostly on power tool batteries. Never thought to make an instructable on the soldering on to the batteries it self, but i have transplanted cells from one battery to another without any problems.

aduy (author)ikssk2011-05-13

i just took a look at your instructable and its very interesting how those big drill batteries are constructed. After I posted this instructable i saw another related one about reviving dead ni-cad batteries to brand new using a disposable camera's flash unit.

ikssk (author)aduy2011-05-13

I have tried zapping my batteries like that, with no success. I think this technique requires to zap each cell individually, and it will only work on Ni-Cad.

aduy (author)ikssk2011-05-13

yes i figured as much, but still worth a try

carlos66ba (author)2011-05-12

Does it hold well? Does anyone know what the material of the battery terminals is??

aduy (author)carlos66ba2011-05-12

im going to delete the part about it not being very strong. i tried to pull the wire that was soldered onto the battery and the wire came off, but not in the way that your thinking. the solder remained on the battery and the wire broke off. so in conclusion, its as strong as a normal solder joint.

carlos66ba (author)aduy2011-05-13

excellent! thank you for (both) replies.

Phil B (author)aduy2011-05-13

Thank you for publishing your Instructable. Many years ago my mother traded in some stamp booklets, like S & H Green Stamps, and let me get a soldering gun with them. It is dual wattage (75 and 100 watts), and works well for tinning a battery as you described. A few years ago I bought a low wattage (15 watt) soldering iron similar to what you show so I would have something for more delicate electronics work. I always reach for the bigger soldering gun when I need to attach wires to a battery because it has more power and heats up the battery ends more quickly. I usually use fine sandpaper to rough up the metal battery ends. It works well, too.

As you publish more Instructables, you will find most people are appreciative and kind in regard to what you have done. The people who make the most unkind comments are those who have published no Instructables and think they are experts on everything. It all looks a lot different when you have published something of yourself for others to comment upon it. Do not be discouraged.

aduy (author)Phil B2011-05-13

thanks, its good to know others have done this. i looked across the inter tubes and hadn't found anyone else that had so i thought it would be good to share this knowledge.

Phil B (author)aduy2011-05-13

It is a good thing that you did this Instructable. Even if others have done it, there certainly are others who had no idea this is possible, nor how to do it.

aduy (author)carlos66ba2011-05-12

also the terminals of batteries are usually made from stainless steel

AndyGadget (author)2011-05-13

Yep, I've used this technique, but just be very careful if you try it on the 3V lithium coin batteries. It's possible but do it quick and clean as these heat up very quickly and can leak or burst.

aduy (author)AndyGadget2011-05-13

yes to avoid that just heat the solder using the iron.

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