LFP Battery Disconnect Solenoid Switches

[blondjohn]

Originally Posted by hjohnson

It kind of depends on how you rig it, but I believe you can achieve that with the Blue Sea 7700 and at least the REC BMS (fail safe with the latching relay).

Using CatNewBee's circuit (basically a couple of capacitors, LEDs, and resistors), you can connect what amounts to two pulse connections to the two NO and NC relay outputs from the BMS. If the BMS fails, and lets go of its own internal relay, that will cause it to switch back, generate a pulse on the "open" line on the 7700, and voila, it goes open. The LED consumes significantly less current than a traditional contactor would.

Thanks for that useful advice. I think an approach similar to what you are outlining will be the best for me. I'm currently digging deeper into the Blue Sea ML-RBS product line (like the "auto releasing" ML-RBS 7713) and I will be trying to get some technical advice for my application from Blue Sea to be sure I am selecting the best product. Rather than building my own electronic circuits I will probably purchase a driver if needed. I will look at the REC BSLRD latching relay driver you referred to, which was also mentioned by Imxr earlier in this thread. I'm also interested in the new latching relay driver that TAO is coming out with.

Thanks,
John