This 5V 10A/20A capacity grading machine is used to test the capacity of cylindrical batteries through cyclic charging and discharging tests. The whole machine has 256 channels and can test 256 cells simultaneously. It uses a customized battery cell holder for cylindrical batteries with diameters from 32 to 60 mm and length range from 90 to 165 mm. The voltage & current accuracy up to 0.5‰ and with energy-saving feedback function.