I have 3 12V SLAs wired in series to drive my Electric Bike. It is an EV Global, so I am using the built in charger that came with that. Due to my abuse of the batteries (not plugging them in at times, etc), my ride has been reduced to a couple miles before I "go red".
My hypothesis is that I probably fried one of the SLAs worse than the others, and if I were to replace that one then I might be able to purchase just one replacement rather than all three. Is that true, or is there some rule that they are going to all go bad equally if the same voltage and capacity?
Given that, what is the best way to identify the problematic battery? Should I measure voltage when charged? Voltage when run down? How much different would one expect to see them.
I only have an analog multimeter, and when I measures the three after running them down it appeared that one was just very slightly lower voltage than the other two.
Many thanks for tips,