no cell runs perfectly. i had a question previously that i had emailed chemlec, and he had done a voltage drop test across his sealed 6 cell series 'lyser, and the results were surprising. some plates took 2 volts, some took almost 2.5, some took 1.5! the thing here is that with slight differences, we get current and voltage pinch points. now its been a while since basic automotive electrical theory, so i cant remember exactly, but doing a voltage drop test across each cell and getting different results shows different characteristics per cell.
however, basic electrical theory tells me that each and ever cell in aseries cell runs the same amount of current. following the current path, you can point to the battery terminal, wire, across the cell, then back to the wire, and finally back to opposite battery terminal. that means that if you have an in-line ammeter in that circuit, it's showing total amps for the circuit.
in a parallel circuit, different parts of the circuit will pull different amps.
but in a series cell, the overall current is the same current in each cell.