With 18650 cells as cheap and plentiful as they are, you’d think building your own custom battery packs would be simple. Unfortunately, soldering the cells is tricky, and not everyone is willing to ...

I find myself in need of welding 40 18650 cells into a pack to rebuild a dead pack. It seems the normal method of doing this is spot welding the batteries together with thin nickel sheet. Does anyone ...

Maglite’s used(?) to be the king of flashlights, but replacing those pesky D-cell batteries is kind of ridiculous in this day and age. So [Travis] decided to upgrade it to make use of the ...

I made this amazing battery pack using 18650 cells, performing about 3X better than a LiPo battery of roughly the same weight and size. So instead of flying for 15 min, now you can fly for 45 min.

If you've owned a laptop for a few years, you've no doubt encountered the problem that the battery eventually loses its ability to hold a charge. Generally what happens is that one or more of the ...