Low Cost basic BMS with external solenoid - NOT FET

[me3]

I want to run a high current motor for 5-300 seconds, within the C rating of the cells. Lets say 100AH cells @ 3-5 C, so a 500A spike then maybe 150A continuous, with the odd ounce higher.

That means a BMS that can handle 500A. This is easy with a Solenoid, difficult with a FET setup.

Who makes a basic / low cost passive balancing BMS that can drive a Tyco solenoid?

 

[Bob B]

The Chargery BMS is one that has used to be popular but has fallen out of favor on the forum .... If you do a search you will find a LOT of information about using it with relays .... If you do a search, you will also find issues some people were having with inaccurate cell voltage readings. Those problems have mostly been resolved by a combination of software updates and powering the BMS via the external power port instead of the cell leads. Seemed like these problems were worse with the 48V versions. I'm still using my 4S Chargery with no issues.

There are others that will drive a relay, but I think they are more on the expensive ... and I'm not up to speed on them.

A forum search will probably provide other options.

 

[toms]

You can use the FET of an e-bike based BMS to switch a contactor.

 

[MurphyGuy]

Doesn't the ZEVA BMS drive a relay?

Zero Emission Vehicles Australia

 

[AntronX]

Power your solenoid with FET output of BMS. Make sure to match solenoid coil voltage to your battery voltage. Could use a resistor if coil voltage is less than battery voltage.

 

[toms]

Doesn't the ZEVA BMS drive a relay?

Zero Emission Vehicles Australia

It does, but they aren’t made anymore unfortunately. They weren’t cheap either, not much price difference to REC.

 

[Marinepower]

Not super cheap but the Electrodacus is designed to do this.

You will need a second SS relay however for contactor's field current as Electrodacus limted to 50mv signal output.