DIY solar trick that saved my battery bank this winter

I kept killing my deep cycle batteries by draining them too low at night up here in Maine. Switching to a simple voltage cutoff relay for $25 kept them above 50% charge and now they last way longer. Anyone else use a low voltage disconnect on their setup?

3 comments

3 Comments

the_terry1mo ago

Man, that's the exact same thing that saved my setup last winter! I was down in Pennsylvania with a 400ah bank and kept killing my batteries by accident. Picked up a cheap 12v cutoff relay for like 30 bucks online and wired it to kick in at 12.0 volts. Night and day difference. My batteries actually made it through the whole season without dropping below 50% once. I even added a little led indicator so I could see when it kicked off and reminded me to cut back on usage. Your mileage may vary but that little gadget paid for itself in battery life no question.

charles6401mo ago

Did you ever try one of those Bluetooth battery monitors with the low voltage alarm built in? I added one last month and it texts me when my voltage drops below 12.2 so I don't even need to check it.

sean_green441mo ago

Took me way too long to figure out the same thing. I was basically running a science experiment on how to kill a battery as fast as possible before I wised up and grabbed a cutoff relay.