Tremors- awesome diagram. Thank you for taking the time to do that. Two questions: 1. I thought the relay/solenoid was a "one way" deal. That doesn't seem to be the case here. So if one battery is lower than the other, they will both equalize when the switch is on.
That's why it's designed so that in normal "ON- Switch up" operation the solenoid is only energized (contacts closed) when the ignition is on (engine running) and the alternator can charge the batteries. Equalization of the batteries is not an issue.
When the ignition is off and the engine is not running. The solenoid is de-energized and the contacts open, isolating the batteries and preventing them to equalize.
When the switch is in the emergency jump / down position, the solenoid is energized regardless if the engine is running or not. It's only used to "jump start" the main battery should it be too far depleted to start the engine.
Maybe your thinking of a diode type battery isolator? They allow current to flow only one way.
2. Why do you need a fuse b/w the auxbattery and inverter? I thought you could wire that directly. Thanks Again. I'm starting my portable build this week.
Call it redundancy
.
Usually if the connections for the inverter is a long run of wire, you'll want want a fuse inline.
Even though it's a short (approx 1 ft) run of wire between the inverter and the battery, I feel better having it there. Especially since theres a lot of bouncing and vibrations off pavement. Perhaps an accidental loose electrical connection popping off and shorting. Or the wires coming out of the box could accidentally rub against something that I load in the cargo area.
Hope this is helpful info.
