6s bms with 6 balance connectors, I need help!

Hey, so i bought a 6s bms and on the balance leads I have only 6 wires instead of 7. I have heard that the bms uses the ground from the main leads.

Can anyone help me to wire it correctly? Here is the diagram for the bms(I am bypassing the discharging)

I guess you manually have to add the B- wire to the plug. Can you give photos of the plugs you have?

You have male / female 7 wire plugs? But only six wires on which side?

oops this one? http://www.bestechpower.com/192v6spcmbmspcbforlifepo4batterypack/PCM-D103.html

There is a 5s which appears to have the same model name for some dumb, dumb reason, make sure that is not what you have.

The 6s one should have 7 pins like this and just like the pcb markings say B- goes to the negative terminal of the battery, the B1-B5 pins go to each series postive


Hmm, right now I left the - pin out, considering that it is actually already connected to the bms via the main cables and the batteries are charging. Maybe the bms uses the negative from the main black cable of the battery?

I just bought this same bms for my 6s setup did you end up figuring it out?

Hi, I wired it, so that all the positives go to the right b pins. I don’t know if this is the correct way, but it has been working well so far.

If anyone can give an exact answer it would be nice. The bms is stated to be a 6s bms. As shown here, but the connector is 6 pin not 7, so that the b- doesn’t lead anywhere.http://www.bestechpower.com/192v6spcmbmspcbforlifepo4batterypack/PCM-D103.html