Just John

Photon Sorcerer
I use anther JBD BMS, that one with 7-20S and 20A and full case. Well it works but as all common port BMS it has the drawback to disconnect charger together with the load. So in worst case your pack goes undervoltage and charges never (unless your charger sits directl on the battery terminals... but then maybe it goes overvoltage and BMS cannot disconnect).

I would always tend to BMS with separate relay outputs.
With a single relay common port, yes it disconnects everything.
With FET based single port BMS, it can turn off just charging or just discharging.
Yes, JBD just recently came out with a 200 amp rated FET based BMS. If you order the right model it even has a port to use with a heating pad for cold weather.


New Member
I know that every FET based BMS I've seen has separate FETs for charge and discharge.
What is your point?
at some point if there is common port the FET drains have to connect together. Then how does the circuit avoid that the other FET just conducts in the reverse direction? You saw any schematics of how this is solved? Diodes in series with the FETs?