Make Your Own Li-Ion Battery Pack





Introduction: Make Your Own Li-Ion Battery Pack

In this project I will show you how to combine common 18650 Li-Ion batteries in order to create a battery pack that features a higher voltage, a bigger capacity and most importantly useful safety measures. These can prevent an overcharge, overdischarge and even a short circuit of the batteries. Let's get started!

Step 1: Watch the Video!

The video gives you all the information you need to make your own Li-Ion battery pack. In the next steps though, I will present you additional, helpful information.

Step 2: Order the Parts!

Here you can find a parts list with example sellers for your convenience.


6x INR18650-25R Li-Ion Battery (USA):

6x INR18650-25R Li-Ion Battery (Germany):

6x 18650 Spacer:

Nickel Ribbon (5mm, 0.15mm):

1x XT60 Connector:

1x 3S Balance Connector:

1x 3S BMS:

Kapton Tape:

16 AWG Wire:

6x INR18650-25R Li-Ion Battery:

6x 18650 Spacer:

Nickel Ribbon (8mm, 0.15mm):

1x XT60 Connector:

1x 3S Balance Connector:

1x 3S BMS:

Kapton Tape:

16 AWG Wire:

6x INR18650-25R Li-Ion Battery:

6x 18650 Spacer:

Nickel Ribbon (8mm, 0.1mm):

1x XT60 Connector:

1x 3S Balance Connector:

1x 3S BMS:

Kapton Tape:

16 AWG Wire:

Step 3: Do the Wiring!

Now that you have all the required components, it is time to do the wiring. You can use the pictures of my finished battery pack and the scheme from the video as a reference.

Step 4: 3D Print the Enclosure!

Here you can find the 123D file and the stl file of my design which you can use to 3D print your own enclosure.

Step 5: Success!

You did it! You just made your own Li-Ion Battery Pack!

Feel free to check out my YouTube channel for more awesome projects:

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2 People Made This Project!


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And here I tried to solder wires to connect 10 1.2V Li-Ion batteries in series, but the solder kept beading and rolling away!!! I had scratched the terminals with sand paper to try and create more surface area for the solder to grip... aside from apparently risking my eyes, can someone tell me what I did wrong? a why couldn't I solder to the battery terminals directly? Was it the magnetic field?

Keep in mind that I only started studying electrical engineering a few months ago, on a whim, and so far my experience mostly consists of taking circuits apart carefully, to collect needed equipment. I want to build a wind turbine using neodymium magnets, some bought, others salvaged, and have a few other projects on the go. I managed to salvage a 6V battery from a kids' toy jeep.

can i charge it from boost converter (because im new in these elect. projects with batteries)

Wow. I can't believe Instructables would feature a project where someone recommends soldering directly to 18650 terminals.

Why is that dangerous (im kimda a noob and have no idea why)

Applying that much heat directly to a terminal of a high-discharge battery is always a terrible idea. Besides damaging the battery, you could also have it explode on you.

An alternative to soldering to 18650 terminals is soldering to 18650 holders that come with PCB mounts. I prefer balance charging them in a holder because it's convenient and doesn't damage their labels. This is good for high powered bike lights!

great video, thank you!

I always enjoy your Great Scott videos. Very informative, well thought out and neatly executed. I concur about the difficulty of making a spot-welder and using solder instead. As long as careful steps are taken to avoid overheating the cells, soldering works as well or better than spot-welding. I wonder, however, why you included a BMS when you're already using a balance charger? I made a similar instructable recently for an e-bike battery pack that included a balance charger but no BMS because there was no room for one:

Thanks Greatscott this is an awesome post!

Correct me if i'm wrong but the cells can be balanced by charging them in all at the same time in a 1S1P configuration with a BMS for that until they are full

If you can easily detach the batteries this is possible. like I can because I bought a holder like they have in RC cars for the cells and did the same wiring as on this post.

Also a perk of this methode is you don't have to risk the batteries exploding on you. and easily replace "bad" batteries.

Make sure though that the batteries are in good contact with the contacts and that they are well attached so they don't go lose.

I will only take out the batteries when I really need to.

- Maarten