First off, I must admit I am not making a bike, rather a battery system for a ham radio portable kit. I am using LEFPO4 batteries at 15AH each. I am building an 8 cell $S battery. I have two questions.
First question; is it best to build the battery with 4 sets (in series) of 2 cells (in parallel) and use one BMS, or make to 4 cell 4S batteries, each with it's own BMS and put them in parallel. I am assuming the first option as I have seen many videos done this way and non doing it the second way.
Second question; I got each set of 4 cells from two places. both have cells that stay pretty close on the voltage (within about .15V difference max). I tested both in a 4 cell 4S configuration partly due to them arriving at different times and partly due to the time to charge/discharge 30AH vs 15AH. One set has just over 16AH charging to 14.6v and discharging to 12v. The other set has closer to 15AH ( forgot to write down on the charge cycle, but discharged to 14.8AH) charging to 14.8V and discharging to 12V. Is that enough difference to worry? And should I put one cell from each batch in parallel, or keep the two batches separate?
Thanks for any help,
Bob
First question; is it best to build the battery with 4 sets (in series) of 2 cells (in parallel) and use one BMS, or make to 4 cell 4S batteries, each with it's own BMS and put them in parallel. I am assuming the first option as I have seen many videos done this way and non doing it the second way.
Second question; I got each set of 4 cells from two places. both have cells that stay pretty close on the voltage (within about .15V difference max). I tested both in a 4 cell 4S configuration partly due to them arriving at different times and partly due to the time to charge/discharge 30AH vs 15AH. One set has just over 16AH charging to 14.6v and discharging to 12v. The other set has closer to 15AH ( forgot to write down on the charge cycle, but discharged to 14.8AH) charging to 14.8V and discharging to 12V. Is that enough difference to worry? And should I put one cell from each batch in parallel, or keep the two batches separate?
Thanks for any help,
Bob