This charger broken, or i need a different one?

[_Jo]

Im trying to reboot my surron battery from a low voltage cutoff and i bought this 67.2v 2a-10a adjustable amperage charger to charge the battery at 2a and get it back up and running slowly. The charger does this: (see video) And it does it when plugged into the battery and when it is not. it also did this on my very first test (not plugged into battery) when it arrived. (The fans mean it is charging) i have tested with multimeter and it ouputs correct voltage just for like 10 seconds with the fan spinning as seen in vid. IMG_6188-compressed (1).mp4

 

[lnanek]

The BMS in the battery pack is probably blocking charge using MOSFETs due to some situation like the voltage of the p-groups being too low for safely charging. You'd have to bypass it and charge directly, I think. Preferably outdoors where a fire won't hurt anything and just enough to go back to safe charging through the BMS. The BMS is generally responsible for important things like balancing the p-groups and stopping the bulk charge if any of them reach the maximum allowable voltage.

 

[marty]

If original charger won't charge battery and second charger also won't charge battery. Problem could be battery. Test don't guess.