the_uglydog
New Member
I have a bank of 6 200ah Lifepo4 batteries. In 2 of them I notice that they shut off prematurely, one at 52.5v the other at 50.9v. The rest of the batteries go down to my 47v switchback to utility with no problems and all cells closely matching their voltages. I see that one cell in each of the 2 that shut off seems to match the voltage of the others when it gets to 54v charging but when discharging the voltage drops more than the other cells. Example all the cells are 3.33v that one is 2.6v. I've tried charging that cell up to match the others but after the battery charges up to 54v it does the same thing. I'm assuming the cell is defective, right? Also one of the batteries is the opposite, the cells match at the low point before the switchback to utility but when reaching about 54v one cell seems to be charged higher. I see that the balancer switches on and off balancing the cells but it's always the same cells that go out of balance. Thanks for the suggestions, the dog