Forum Discussion

ac_bill1's avatar
ac_bill1
Explorer
Dec 22, 2013

Dumb question perhaps?

New to the game, so still trying to learn all the in's/outs..

When you have your rig's "shore power" hooked up, I gather it maintains a charge on the coach batteries, but does it also charge the engine's battery?
I thought that it may charge all three, as my dashboard has a push button switch on it, for extra juice from the coach batteries for cold starting. Figured they must all be wired together. After thinking it through a little more, I wondered if the starter battery remains isolated completely, unless the switch is actually pushed, so perhaps it's not being charged at the same time..

While I'm on this area..Is there a way to test that your shore power unit is actually working properly? I sure don't want my batteries boiling dry if I leave it plugged in all winter, or to find out they are dead flat in the spring..Suggestions?
Class C
  • 2chiefsRus's avatar
    2chiefsRus
    Explorer
    Dec 22, 2013
    It really depends upon your particular coach. Even on ours, the owners manual said that the engine and coach batteries would both be charged when hooked to shore power but turns out that was WRONG and a misprint in the manual per Monaco when I contacted them. We added a small part and now whenever the coach batteries are fully charged, it will flow over and charge the engine batteries. The switch on your dash is there to allow you to use your coach/house batteries to start your coach in case your engine batteries are low or dead. You wouldn't want them all tied together or you could end up with all dead batteries and no back up plan.
  • ronfisherman's avatar
    ronfisherman
    Moderator
    Dec 22, 2013
    Depending on year and model of your MH it may or may not charge the chassis batteries when hooked to shore power.
    As already stated, check your batteries when hooked to shore power for voltage. Charging voltage should be around 13.6. Chassis battery should show a charge voltage similar to coach batteries.
    If Chassis batteries are not charging look in installing a TRIK-L-START
  • snowdance's avatar
    snowdance
    Explorer
    Dec 22, 2013
    You got it right for most of the C class motorhomes. When the engine is running it charges both truck and house batterys. When hooked up to shore power the charger charges the house batterys. The dash switch will let you start the truck with the house batterys if it is down and house batterys up. Your house generator will charge only the house batterys only in most cases.

    When pluged in some chargers will cook the batterys. Others will care for them and just go to standby when charged there are a number of brands so no way to know what you have with out looking at it and reading what you can.

    If you did not get the manuals for the stuff in your rig they are on line. Post if you need them and I will post the address.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Dec 22, 2013
    When connected to shore power your converter will maintain charge on batteries

    TO check if working...converter output should be 13.6V DC

    Where batteries boil due to overcharging..depends on type of converter/charging
    If it's a single stage or a three stage converter/charging system

    Look up your converter brand/model or post it here

    You should check battery levels periodically regardless.
    At first I checked mine monthly then at 3 month periods....now 2X a year.
  • John_M1's avatar
    John_M1
    Explorer
    Dec 22, 2013
    Actually not the case in many motorhomes.
    In both our previous Class A and our current Class C being plugged in did not charge the chassis battery. In both cases I added a Trik-L-Start device to charge the chassis battery while plugged in.

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