Forum Discussion

grandpalarry's avatar
grandpalarry
Explorer
Dec 25, 2014

Charging house batterys

How the heck do you charge a 4 pac. house battery.
We had a power outage that knocked my EMS off line and everything switched to the batteries (we were on a long trip and the coach was in storage)

Came home and dead batteries.
I would like to charge them, rather than replace them if they will hold a charge.
Can I charge the set without removing all the cables ?

40 foot HR Diesel.
Thanks Larry
  • Yes, you can charge them as they are-- probably.

    Part of the answer depends on how deeply discharged they are and what converter, charger or inverter charger you have. Some will not charge a totally dead battery, requiring you to use a small charger to get it started.

    I would plug in/start generator and see if the on-board system takes care of it.
  • RoyB's avatar
    RoyB
    Explorer II
    The Batteries are probably not going to make it... Even if they do show re-charged you can expect their performance will be greatly reduced...

    Most of us don't have very good luck recovering batteries after they set in an discharged connected state for a long period of time.

    Sorry for not so good news - You might pull it off but chances are they are too far gone to bring back...

    Maybe the Battery Experts on here have some good ideas for you...

    Roy Ken
  • Yup, the longer a battery sits and the deeper the depth of discharge during that time, the less the likelihood that the batteries can be brought back to give you serviceable performance. But, you really have nothing to loose by trying.
  • Hi,

    Check that the electrolyte covers the plates--if it does not add just enough distilled water to do so.

    Start by fully charging the batteries. This may take 168 hours.

    Next do an equalization of the batteries.

    Then discharge them to 12.3 volts under load.

    Fully recharge the batteries again.

    Top up the electrolyte to the correct level.

    Equalize the batteries again.

    Best of luck with this process.
  • 'Equalize charge' talked about in the above process is charging them to about 14.4 volts for about 6 hours after reaching the 14.4 volts. This will boil out a lot of water, in addition to hopefully flaking off any accumulated deposits on the battery plates.

    Problem is your battery might be accumulating debris under the plates, and once that debris is at the plate level, the battery shorts between the plates, and that is the end of that battery. Hopefully there is enough space under the battery plates, and you can recover them.

    As stated above, some battery chargers will not start from a 0 volt battery, or even a 4 volt battery. You might have to start the engine, and then you will be applying 12 volts from the engine alternator, to the coach batteries. I would not leave the engine running long, not more than say 15 minutes, you can overheat the alternator - it will be putting out the max current during that time, and it is not good for them.

    You might also have a bad converter/charger, or it might need power to turn it on. My inverter/charger requires 12 volt power to energize the remote control, and the remote control turns on the charger or inverter.

    I have a solar system that can fully recharge my batteries in about 4 days. It is rated at 300 watts. It would at least keep the battery from going dead during a extended power failure. SunElec.com sells solar panels for a reasonable cost.

    Good luck!

    Fred.
  • wolfe10 wrote:
    Yes, you can charge them as they are-- probably.

    Part of the answer depends on how deeply discharged they are and what converter, charger or inverter charger you have. Some will not charge a totally dead battery, requiring you to use a small charger to get it started.

    I would plug in/start generator and see if the on-board system takes care of it.


    X2 Plug it in and see what happens.