For the price of a mid-range Android phone, [Kenneth Finnegan] turned a 50 caliber ammo can into a 50 amp-hour portable power supply. The battery pack uses four 3.5 V LiFePO 4 cells wired in ...
He decided to make a 12V power supply out of an antique ammo can he found at an army surplus store. The .50 cal ammo box wasn’t in the greatest condition when he picked it up, so he completely ...