Forum Discussion

paulgreenwood1's avatar
paulgreenwood1
Explorer
May 18, 2016

House Battery Dies Quickly

I own a 2004 Coachmen Mirada class A. Last year I replaced the house battery. Now my battery won't run my lights for more than a couple of hours before dying. As I live in Florida, I figured maybe the heat was killing the battery, but, after further reading, I'm not so sure. Can anyone suggest why my battery dies so quickly? Is there a way that I can check if it is being charged sufficiently when rv engine is on? I do alot of boondocking, so my HB is usually only being charged when I drive. I have noticed, however, that when I camp and am plugged in, the battery also does not last long after disconnecting from shore power.When the rv is not in use, I make sure to push the battery disconnect, so it is not in use when sitting for long times idle.Maybe just a bad battery? It is deep cycle marine battery. I also read that completely discharging the hb will cut down the life. In future, should I turn lights off when battery reads 1/3?
Class A
  • 2oldman's avatar
    2oldman
    Explorer II
    May 18, 2016
    OP..you may want to change your original post as it appears people don't read all the replies.
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    May 18, 2016
    If a A/C uses 10A AC then it will draw about 110A DC from the battery with the inverter. If nothing else the battery will soon be toast.
  • WILDEBILL308's avatar
    WILDEBILL308
    Explorer II
    May 18, 2016
    paulgreenwood1 wrote:
    I own a 2004 Coachmen Mirada class A. Last year I replaced the house battery. Now my battery won't run my ac for more than a couple of hours before dying. As I live in Florida, I figured maybe the heat was killing the battery, but, after further reading, I'm not so sure. Can anyone suggest why my battery dies so quickly? Is there a way that I can check if it is being charged sufficiently when rv engine is on? I do alot of boondocking, so my HB is usually only being charged when I drive. I have noticed, however, that when I camp and am plugged in, the battery also does not last long after disconnecting from shore power.When the rv is not in use, I make sure to push the battery disconnect, so it is not in use when sitting for long times idle.Maybe just a bad battery? It is deep cycle marine battery.

    What is AC if you are saying airconditioner I think I can help. STOP trying to run the AC on one 12v battery. You can only run the AC from shore power or when the generator is running. You have probably ruined that battery by over discharging it repeatedly. The only way to know is to charge it fully charge it then load test it.
    You say you do a lot of boondocking I would upgrade to at least two 6v golf cart batteries, if you have room I would try for 4. You still won't be able to run the AC on battery power but the batteries will last longer boondocking.
    Bill
  • paulgreenwood1's avatar
    paulgreenwood1
    Explorer
    May 18, 2016
    Sorry, guess I forgot to turn on the brain switch this morning. Let me rephrase....battery does not run lights for a few hours before dying. Even after using generator for air conditioning for a couple of hours, my battery dies quickly when generator is off and battery is powering lights/fridge.I figured a few hours with the generator on would have charged the house battery fairly sufficiently...
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    May 18, 2016
    Doubtful that an air conditioner would run or even start on a marine battery.

    First step is to have the battery load tested at a auto store for free. Next you need to determine your usage. A DC clamp on ammeter or battery monitor would be helpful.

    Also a marine battery is slightly better than a starting battery but it's not a true deep cycle battery regardless of what you read on the label.
  • Dick_B's avatar
    Dick_B
    Explorer
    May 18, 2016
    I guess the battery is powering the inverter that is running the air conditioner. Right?
    I have trouble believing that the battery would last very long under these conditions.
    To be sure I would take the battery to someone for a load test; not just testing voltage at the terminals.
    Even new batteries can be bad too soon.
    Where to buy? Try Batteries Plus.

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