No Spot Welding Necessary to Build Your Own 18650 Battery Packs
The Cell-Lock modular battery assembly system is designed to make it easy to build battery packs for electric bikes and other vehicles.
It has never been easier to build custom electric vehicles, but there is still a big challenge and that is constructing a battery pack. It isn’t easy to make a rechargeable battery pack with the right voltage and capacity, in the right form factor for your vehicle design. The traditional method involves spot-welding, which is intimidating. To make the entire job more convenient, Ben designed the Cell-Lock modular battery assembly system.
18650 lithium battery cells are ideal for custom battery packs, because they’re affordable and easy to source — you can even salvage them from used battery packs. And thanks to their small size, you can assemble them into whatever larger shape your vehicle design requires.
However, you still have two things to figure out: physically assembling those batteries into the larger pack and making the connections between them, which can be in series, in parallel, or both. The usual way to do the latter is with nickel strips spot-welded on to the battery contacts.
Cell-Lock makes both physical assembly and electrical connections easy. Each Cell-Lock module is a 3D-printed cap that fits onto the end of an 18650. Print two of them for a single battery cell. Those caps provide both a means for physically attaching cells to neighboring cells in any shape you like and for making electrical connections between them.
The physical assembly is straightforward, because you only need 3D-printed mechanical parts. However, the electrical contacts are a bit more complicated. Cell-Lock requires copper contacts in a specific shape. To make them, Ben had Send Cut Send cut the copper contacts to size and then he used jigs at home to bend them into shape. Other techniques may be more efficient, but will depend on your equipment and capabilities.
No matter how you make the contacts, you can put together an entire battery pack in minutes once you have those and the 3D-printed parts on hand. The resulting battery pack should be very strong and robust.