/diy/ - Do It Yourself

how stupid of an idea is this ups? 1 charge resistor, 3 balancing resistors, a high-current schottky diode, and that's it. the input is a 12v smps, so backfeeding is no issue. the hdds running on it can handle as low as 10.8v, so i wouldn't get that much out of the cells (maybe 20%), but it just needs to be enough to keep the system running long enough to tell the raspi to shut everything down

if someone can tell me how long an 18650 will last when kept at 4v per cell for years that would be great