GIGAVAC GL100ABANA 100a 0-800vdc 12v Relay

These were recovered from EV battery modules. These are VERY EXPENSIVE online and here just $15. If you have any project that needs a high current relay this is your chance to save some money.

Make a cheap 30a BMS into a 100a BMS. This will work for batteries in the 12v range so perfect for Lifepo4 and Lithium Ion 12v. Wire your BMS like normal except the C- that goes to your charge and discharge will go to one of the small black wires on this relay. The other wire on this relay will go to the positive of the battery. When the BMS is on it will trigger this 100a relay on. When it detects a problem the BMS will shut off and trigger the 100a relay to shut off. Now your main positive wire for charge and discharge will go right to the battery positive and the 100a relay will go in line with your main negative wire. You will want to add a fuse in line as well to protect from an external short or fault that is not battery related. Let's say a charge controller breaks and causes a short, you need a fuse to protect your battery from that. We have great high amp fuses for cheap and you can also find them on Ebay too. Do not use this with a BMS without adding a fuse because you never know what equipment could fail. Chargers, charge controllers, and inverters can fail and you need to protect the battery against that.

The relay can handle up to 100 amps and works up to 800vdc but the trigger wires work for all 12v systems.

If you use a solar charge controller to charge a 12v battery this is perfect. Connect one of these to the output of the solar charge controller and if it ever fails and shorts this will disconnect the circuit before it does damage to your batteries.

There are many reasons and applications for using these relays and there is no need to spend hundreds of dollars on them when we have them here for a small fraction of the price.