Moved it to the battery compartment of my Chinook motorhome as it is larger than the original relay. It seems to work well for the isolation of the battery systems. Very happy to find this product!4th one of these i bought and installed, i use them in every truck i own and it's the first modification i do to everything i buy, it just works and has saved me, others and helped out on more occasions than i care to remember, having a spare truck battery for ??? is always going to be helpful.... your alternator dies on you and your starter battery goes with it? no problem, switch to the "house" battery, start 'er up and limp back into town, want to test some electrical work your doing but don't want to take the starting battery in and out every time you do something? no problem, just isolate the 2nd batt while you're doing your work and open it back up to do your testing...there's a lot more a 2nd battery can do for you than just running a winch, lights or fridge....that said, i have one of these in my wifes suv for no other reason than to run her fridge and to not have to worry about her being stranded somewhere with the boys due to a dead batt.good investment....just wish they were like $50-100 cheaper...i used to have essentially the same function for a $20 solenoid and a $10 switch..this is no doubt cleaner, more robust and last way longer but it's still hard to justify the $150 cost differnce between the two setups even if i was frying solenoids every couple of years.I am using this to auto charge the secondary battery in a marine application. I added the secondary battery to provide independent power to all but the engine ignition, starter, and electric fuel pump. The alternator is also on the primary battery side. I originally used a manual 1-2-all switch, but when I would crank the engine, the voltage drop caused my electronics to reboot. I changed the switch to a This is a quality ACR, but has some notable flaws for common use cases:1. You can't use it with lithium house batteries because it detects the higher voltage of lithium as an active charge and keeps the house and starter batteries connected.2. It's loud and the shut-gun-like snapping as it connects, or _tries_ to connect when switched off manually is startling. Not ideal when the engine room is adjacent to your bed.However, it has been reliable and solid for what it is designed to do. And it's efficient because it's a relay.Blue Sea makes great quality products with clear install diagrams and instructions. However, after doing hours of research, I thought I had what I needed in the SI-ACR 7610. Turns out it's not the "isolator" solution I need. Dual sensing means it charges both banks both directions as long as either bank has 9.5volts or above. This means when my solar charger is sending 14.7volts to my "house" battery bank, my starter battery is combined and receiving overvoltage on a fully charged battery. Killed my starter battery in no time. It does not isolate batteries, but combines them when a charge is detected from either bank (a.k.a. "dual sensing"). Need to find a true isolator that meets my needs...and a new starter battery!Great product otherwise for specific application.Works fantastic and well made.Works great! I did not realize the unit has the status LED indicator built in, so I bought the LED to hook into the REMOTE spot and didn't need it. I always trust Blue Sea equipment for all my auto, camper, and other 12V projects!Installed recently, so far so good, super-solid build quality. use to connect a house battery (with connected solar module) to engine battery so either can pass power back and forth. The unit is very simple with two main power lugs (one for each 12V battery) a spade lug for ground sensing (required) another lug for start bypass (optional) (disconnects the house battery during engine start) and a lugs for an optional remote 12V LED status indicator (unit has integrated LED indicator).Premise of operation: Unit connects battery sources together if one *or* the other have a higher voltage (its a relay so when connected both batteries are wired together) Example, I have the engine battery and alternator and a house battery with solar, I want the alternator to charge the starting and house battery but not allow house loads to pull from the starting battery when engine is off (typical configuration) however, I also have a solar PV module that produces surplus power so charging the starting battery with excess power is preferred. So the house battery connects to one terminal, the start battery to the other, if the engines running the start and house battery link, if the engine is off the start battery is disconnected from the house battery *unless* the solar output pushes the house battery voltage above 12.8v, then the relay will close and link both batteries. Once the sun goes down, the relay opens separating the batteries again.very good bit of kit for the landrover and works a treat. has to be the bst auto charge relay out thereI bought this to replace a defunct Balmar Duo-Charge (a very patient Balmar tech ran through the multiple LED programs over the phone, diagnosed it was not functional, and recommended the Blue Sea ACR.It was relatively easy to install, once I bought 100A fuses, one for each terminal, just to be safe (as per the Blue Sea instructions). It's elegant, needs no operator input and keeps my batteries in good shape with a solar feed when the sun's out and the engine alternator when it's running. Highly recommended.This little unit is absolutely awesome. Instruction are really clear. Using it in my Westfalia to charge my second battery when moving around with the van. Was really easy to install, is pretty straight foward. Looks really well built and solid.ACRs are a large step above common isolaters and this is the good one. Easy to install, be sure to plan for the appropriate cables and fuse blocks between your banks and this unit.Après un an d’utilisation, cet article fut défectueux. Impossible d’avoir l’assistance du fabricant. Très déçu de la fiabilité.