Forum Discussion

Devoredude's avatar
Devoredude
Explorer
Jan 03, 2014

Battery disconnect and charging

I have two battery disconnect switches on my 07 terra, one for the chassis, one for the pair of 6 v coach batteries. I always turn these off when parked. I am connected to shore power and was wondering if this charges my coach batteries with the switch off?

Thanks and happy new year!
  • Typically NOT. The switches are designed to totally isolate the batteries so there is no potential for drain. I've been told several times that for the system to charge the batteries they must be switched on.
  • I do not think there is one right answer to this question.

    On my coach...my inverter is wired directly to the batteries since I have a residential refrigerator...

    Flipping the battery disconnect switch does NOT turn off my fridge since my fridge gets powered from the inverter which is making AC from the house batteries...so for my setup...having the battery disconnects disconnected and my AC cord plugged in would still charge my batteries...

    It all depends on how your inverter/charger is wired.

    When you flip the disconnect switches...does that kill your inverter?...I would assume it would IF your inverter is on the opposite side of the switch from the batteries...

    Like I said...on mine...when I flip the switches OFF to disconnect the batteries...my fridge will STILL work and my inverter/charger STILL has power going to it...so I know which side of the switch my inverter/charger is.

    Good luck,
    joe.
  • I'm with Joe. It just depends on how they wired it up.


    On ours they kill almost everything, but there are a couple small wires directly on the batteries that still have power, smoke and propane detectors, engine and transmission computers, radio memory, stuff like that.
  • With switch off. Put a tester on the batteries to see how many volts they have.
    If 13V plus then the charger is charging them.
    If only around 12.4V then charger is not.

    Turn switch on and there should be 13 + again.
  • Depending on what came with it (convertor vs. invertor/charger), you could be shortening the life of your 12V stuff by not leaving the house batteries in.

    The converter can have a pretty high voltage on it without the batteries switched in and that high voltage can burn up lamps pretty quickly.
  • On a Terra, with the factory installed converter, your batteries will NOT charge with the disconnect switches OFF.
  • Thanks, switch (s) must be on.
    I put a volmeter across my 6V coach batts, read 13V (we just got back from a desert trip so they are fully charged). Plugged in, same voltage, 13. Flipped switch and it reads 13.5. Also, the engine battery switch needs to be on to charge the engine battery which make sense.

    Happy New Year All!