回答“Replaced Battery, Constantly Reboots and unchanging battery percent”I also had the new problem of rebooting and unchanging battery charge levels after battery replacement, (although greatly improved battery life), the problems were fixed with installation of a second battery. My 5S battery has 3 terminals, call them ABC. I had ~4VDC from A to C, but A to B or B to C were 0V, and infinite ohms (using either polarity, note that measuring resistance on a potentially energized circuit is only meaningful if it's actually an open circuit as was mine). The 3 conductor flat ribbon cable goes to a tiny circuit board on the battery cap, likely something was wrong there as the 3pin flat ribbon connection to main board connector was good. My good battery measured a few volts A to B (about half the voltage of A to C), but it should not read an open circuit as the bad one did.