18V Li-Ion Battery BMS PCB Charging Protection Circuit Board Plate - won't charge

[smaniak]

This battery PCB is new but was put in not its original charger, and now the battery won't charge.
First of all BMS chip is without a name. It is 20 pins but no marking.
On this board, I can't understand where B- the line is connected to the board.
Any suggestions about the BMS Chip and other things to look for?

[sam_sam_sam]

It had a fuse able link and it broke or burned up I would use an incandescent light bulb and go from the battery negative terminal to the “B-“ negative terminal on the board and see if it lights up the light bulb with out any load on it if does not light up at all then put on the battery charger and see if light up that way if it does then does it charge up the battery and how bright is the light bulb at this point does it dim as the battery voltage goes up if so then it might have been the power tool that causes this issue because of over loading it

One note the battery charge might not like this arrangement if this is the case then use a ten amp fuse instead but make sure that it is a quick blow type of fuse otherwise use a 5 amp slow blow instead either one will give you the protection if something is wrong
with the BMS protection board

All most all battery power tool have there own battery charger and they are not interchangeable this might explain why this happened to the negative battery terminal to the negative terminal on the board

I hope this helps you to figure out why the fuse able link disconnect like that