RV battery with electric charger,

Is it safe to hook up a solar charger to an RV battery if the RV is plugged in to grid power and has an onboard charger?

Would the power from the solar charger feed back into the electrical one and cause damage?


  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: RV battery with electric charger,

    Define "safe" . Is it safe to drive down the street without a repeat offender drunk with a pulled license hitting you ?

    A 5 or 10watt solar panel, charging a >100AH vehicle battery is generally fine. If "shore power" is going to be connected, it's redundant redundant, but good quality gear shoudl not generally be adversely affected.

    So my question is, if you have shore power, why bother with adding solar?
    If you have solar, why bother with shore power ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 32,999 admin
    Re: RV battery with electric charger,

    In general, you can put multiple good quality chargers (wind, solar, shore power) in parallel to charge your battery bank.

    Normally, you will will want multi-stage charge controllers with a remote battery temperature sensor.

    Depending on the battery type you use (flooded or AGM/Sealed cell) you may need a charge controller with an equalization cycle (needed for flooded cell, not usually needed for sealed cell construction).

    If you have two or more charge controllers, you will get an issue as to which will provide the most power (i.e., the one with the highest voltage setting) and you don't want all three of them to each do the equalization cycle independently (will over charge your battery).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: RV battery with electric charger,

    Yeah, I think the shore power would do most of the charging and probably take away any benefit of the solar hookup.

    I'm now thinking about just running a separate Panel, controller, battery, inverter to run the refrigerator.

    Thank you for your replies.
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: RV battery with electric charger,

    Be advised that if you are considering running your RV fridge (Propane/electric) The heating element will require a large array to run. On a normal Dometic RV fridge the 120vac element will draw ~325 watts. This is a very big draw for a small solar system and will require a significant battery system.

    Aside from that,, the fridge is way less efficient on electricity than it is on gas.

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