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 have an Ergorapido Handheld vacuum with 18V Lithium battery. Recently it seems that the batteries are dying, it gets only 15-20 seconds of runtime. It's almost 3 years old, but I'm not sure if ...