Blue Sea Systems7622 ML-ACR 12V DC 500A Automatic Charging Relay with Manual Control, Gray

I installed this smart battery isolator 3 years ago in my van, and so far it's been working flawlessly. I really like the fact that it allows the charge direction to switch automatically depending on my charging source, and it keeps the house and vehicle batteries fully charged. I do a lot of off-grid camping in remote areas, so the ability to use the house batteries to jump start the engine (if vehicle batteries are low) is important.

Super clean design, and very functional. I installed it in my overland rig to manage a dual battery system. This switch keeps my cranking battery charged and doesn’t allow other accessories to drain it all the way.

Bought this for my class B camper. I’ve had it installed for about two months and it works great. The auto feature disconnects you from the battery and connect you. The latching feature works good. I checked current and it’s pulling less than 0.1 of an amp. The control switch is also an indicator for latch unlatch.

this charging relay is awesome, it really makes the dual battery setup shine. I venture out 3-4 hours one way outside of any cell phone coverage often, this charging relay with a second battery puts my mind at ease.on my last trip and first time using this setup I latched the two batteries together for the 4 hour hwy portion. once I hit the dirt I unlatched the two batteries till I hit pavement again a couple of days later.generally I leave the remote switch in auto mode in the city. this charging relay is smart and does all the thinking for you.I am an land/marine electrician and woods adventurer and can't recommend this unit enough, just buy it and be done!

Installed on boat when I added a second battery. Boat motor now charges one or both batteries while motor is running. Automatically switches while engine is running without burning out the boat motor rectifier. This item is largerand heavier than expected. Labeling on the device could have been made to be seen better so device can be more understood once installed on boat in not so well lighted area.

There is a lot of labor required to install these. The included switches are pretty lame. I had to buy separate brackets and build a wire harness. They are really loud as well. Solenoid pops like you blew a huge AC breaker. These seem like they should be $59.99 not retail for $319.99

Easy to install, very satisfied

BETTER THAN FLAWLESS. POLICE APPLICATION ON ESCALADE. DUAL BATTERIES AND THIS ONE KICKS ON TO CHARGE OTHER BATTERY WHEN IT REACHES VOLTAGE OR YOU CAN ELECTRICALY OR MANUAL JOIN BATTERIES. BATTERIES JOIN AT THE WINCH WHEN ON SO INSTEAD OF ONE BATTERY FOR CAR AND ONE BATTERY FOR POLICE EQUIPMENT IT MAKES 2 BATTERIES WITH DOUBLE AMPS FOR WINCH. OUTLIVED EVERY OTHER APPLICATION I HAVE USED IN 50 YEARS/