Charging lipos with a bms

I have a 12 s setup, with four 3s lipos in series. I have them all hooked up to a BMS, and when I run current into the charging port for the BMS, it charges at around .13 amps. The batteries are 8amp hours, and I want to charge that 1s. I got a power supply that can do 480 Watts, at 50 volts. For some reason, though the batteries are charging really slowly. After 7 hours of charging, the voltage only increased by 1 volt, from 44.5 to 45.5. do you guys have any idea what’s up?


Power supply

Also, when I hooked the power supply directly to the lipos, it drew the same amount of amps.

After a couple hours of charging through the bms, there is a .1v discrepancy between the most charged and least charged cell, which obviously isn’t right

Are you sure you are feeding the charging current through the charging negative?