Stinger SGP38 80-AMP Battery Isolator and Relay,BLACK

Added a second battery to my fj cruiser and wanted to isolate the house battery when the engine was off so that my starting battery would be fresh to start, this is well made and works perfect.I added a switch inside the cab so that I can also shut off manually

Exactly what i ordered, and work great.

Installed for use with second battery, install was easy

Had to return this one for an upgrade. Stinger makes good stuff!!

Works well, easy to install

Awesome value

This wasn't exactly what I was looking for but it does the job and does it well. I was looking for an isolator and this doesn't really isolate the batteries until the ignition is off. I also installed this in a boat that doesn't have a true ignition source. ( push button start with a sealed switch that I couldn't break into ) I ended up running a small wire from the battery to a switch on the dash then to the isolator. I hit the switch to activate the relay.There is very little info anywhere on how this works so maybe I can help some future buyers. It is simply a relay swith. One large power wire from charging source to first battery, then another large wire from that same post to one of the top posts on the isolator/relay. Lastly you run a large power wire from the 2nd top post of the relay to the second battery. When you turn on your ignition it sends power to the unit which engages the relay completing the circuit between the two batteries, thus connecting them and simultaneously charging them. Turn ignition off and the relay disengages making it impossible for one battery to drain the other but also makes the second battery unable to be charged. ( why it needs to be a true ignition source )

So far it is working Great! As described.Easy to wire, the only confusing part was finding a True Ignition Source (which tells the isolator when the car is ON/Ignition). I found out that you can simple jam the wire for True Ignition into a Fuse spot (the fuses right by the driver seat) that is labeled as IGN. This IGN fuse will be for an appliance in your car that is only on when the Car Key is turned all the way, and the car engine is running (I used my Heated Seats fuse slot , as I dont have heated seats, and this spot was labeled as IGN). Any fuse slot for appliances that run when your car engine is off will not work (radio, headlights, windshield wipers, etc.).Also, if you dont want to jam the True Ignition wire into the fuse slot, you can buy a special adapter at an Auto Parts Store. I saw one that looked like a fuse with a little extra box hanging off the end.Good Luck