Forum Discussion

garmp's avatar
garmp
Explorer II
May 08, 2022

Power drain

We are not full timers at all. Our coach will sit for a month or so, especially in the winter months. We do start it and check things periodically. Without starting & running frequently it seems that our engine battery drains to the point it needs a jump to restart.
My question where & how do I look to find the source of the drainage?
I know nothing of electricity other than when you stick your finger in outlet it hurts. A lot!
Your thoughts?
thanks
  • OK Grit Dog, what do you think is the cause? Keep it simple, I'm a dummy, please.
  • 3_tons's avatar
    3_tons
    Explorer III
    Grit dog wrote:
    LittleBill wrote:
    engine battery's will die without being disconnected or hooked to a trickle charger. the computer will run it down over a month.


    No, it shouldn’t.


    It Absolutely WILL, this is because in spite of the engine being off, there are still a couple of active networks alive and running (the most obvious is anti-theft), and this malady is WELL KNOWN to most, and from my car experience 3 or so weeks is about the upper limit, though considerably longer on my dual battery Ram diesel, but STILL a factor that can definitely lead to premature $$ battery failure…This is not theoretical!!

    3 tons
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    There are several systems in modern vehicles that are powered full time.. The ECC for example (Engine Control Computer) and the more modern the more computers. Parts of the radio... and of course batteries "Self discharge"

    If you are full timing then you likely have "Shore power" and you can install a device called a Trick-l-start.. Simple 3-wire hookup at your isolator solenoid or battery control center.

    NOTE if the rig is new enough you may have a problem with the Battery Control Center as many modern RV's use a BiDirectional isolator device (B.i.R.D.) so that the house converter/charger also charges the chassis, same as the engine alternator charges the house when driving.

    Also. I know the "Side terminal" batteries used on some vehicles are not supposed to need terminal cleaning..... but they do.
  • Grit dog wrote:
    LittleBill wrote:
    engine battery's will die without being disconnected or hooked to a trickle charger. the computer will run it down over a month.


    No, it shouldn’t.


    Depends on the misc background loads but it certainly can.

    Also, the battery will self discharge over time. The chemical processes slow way down but don't shut down entirely, even if there is no load on the battery.

    Plus, if the OP has let the battery get run down to the point it needs a jump several times, good chance the battery is far from tip-top condition, so that can compound the issue.

    The use of a good high amperage disconnect switch is a great option. If you are worried about the shop, hang a note from the rearview mirror reminding them that you have a battery disconnect switch and it needs to be used if the rig won't be run for several days.

    A small trickle charger is also viable if the rig is outside where you can place it in the sun.
  • The are all kinds of parasitic drains that you never think of. They can be as small as the vehicle clock, the various memory sets, the CO monitor, all kinds of itty bitty draws that together add up over time.

    The simple solution is to install a battery switch & turn it off between trips. This is something boaters who keep their boats away from shore on moorings are familiar with. The boat is left electronically dead, except for it's bilge pump which is wired directly to the battery. RVs don't need to worry about sinking.

    A battery bank in good shape will sit multiple months disconnected & untended.
  • garmp wrote:
    OK Grit Dog, what do you think is the cause? Keep it simple, I'm a dummy, please.

    Cause of getting multiple cats stolen? Not sure I can give you advice there. Other than doing the same thing with the same undesirable result repeatedly being not very smart is not very smart.
  • If regarding your vehicle battery draining, look it up. Easier than me explaining diagnosis and potential causes to verify if your battery dying is “normal” or not.
    Or just believe the peanut gallery who says it’s totally normal. (Yes I do realize there are parasitic minor drains. But there’s a little more too it that neither the Op nor any of you have addressed )
  • 3_tons's avatar
    3_tons
    Explorer III
    Any new car dealer will tell you all you need to know about this, in fact the commonly used term they use is called ‘Lot Rot’ a malady they have to stay regularly on top of…

    3 tons
  • A small 15 watt solar panel will keep the chassis battery tendered. The one I bought to replace to old one works even when the Tyvek cover is on.
  • There are all kinds of parasitic draws in a modern vehicle. It started with a clock & now vehicles are smarter than us & always alive.

    If stored for months at a time disconnect the battery. Leave the vehicle electronically dead.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,191 PostsLatest Activity: Jan 19, 2025