Forum Discussion

snapper388's avatar
snapper388
Explorer
Jun 16, 2014

converter to battery wire length ?

I read that the distance from the converter to the battery should not be more than ten feet the wire on mine is 8 gauge but is closer to thirty feet. my trailer is a 32' park model that is total electric it has 12 12 volt lights with 2 bulbs each and a 12 volt thermostat all appliances are 115 vac there is no convenient place to put it closer. do I need to use larger wire? or will 8 awg be big enough. I have a new converter ordered and would like to do all that needs to be done at the same time. if the wire is not big enough what size do I need?
  • Sandia_Man's avatar
    Sandia_Man
    Explorer II
    Jun 16, 2014
    Upgrading converter to battery wiring when upgrading converter is rarely a bad idea although in the scenario you presented it is irrelevant. You should be fine with stock wiring unless you have plans in the future for camping off the power grid where quickly recharging depleted batteries becomes important.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jun 16, 2014
    snapper388 wrote:
    I read that the distance from the converter to the battery should not be more than ten feet the wire on mine is 8 gauge but is closer to thirty feet.


    You read the distance from battery to an INVERTER should not be more than 10 feet.. Converters are a bit less limited as a rule.

    There is a chart that gives the likely voltage drop for a given size of wire over a length.. Though you may need to do some math.. I will look up and do the math for you.

    8ga wire has 0.6282 ohms resistance per THOUSAND feet or 0.000682 ohms per foot.. So 30 feet would have 0.02046 ohms which at 50 amps would drop you one volt. That is significant voltage drop.
  • Golden_HVAC's avatar
    Golden_HVAC
    Explorer
    Jun 16, 2014
    It's a PARK model.

    If you rarely use a generator or do not unplug the RV from 120 volt power, then the battery to converter length will not matter.

    Your #8 wire will carry up to about 40 amps, and because you are always plugged in, it should normally have less than 1 amp going through it.

    Fred.
  • ScottG's avatar
    ScottG
    Nomad
    Jun 16, 2014
    snapper388 wrote:
    I was told at the rv dealer that I had to have a battery for the converter to work right. I also like to have a battery because of occasional power outages.


    It depends on the converter. Modern converters don't put out the ripple the old ones did and so they don't need a battery for filtering purposes.
  • snapper388's avatar
    snapper388
    Explorer
    Jun 16, 2014
    I was told at the rv dealer that I had to have a battery for the converter to work right. I also like to have a battery because of occasional power outages.
  • Francesca_Knowl's avatar
    Francesca_Knowl
    Explorer
    Jun 16, 2014
    If it's always plugged in, why bother with a battery at all? A converter works just fine all by itself converting 120v to 12v for direct use use by 12v fixtures.
  • ScottG's avatar
    ScottG
    Nomad
    Jun 16, 2014
    The time the small wiring will be an issue is if the battery gets depleted and then you wan't to charge it quickly with the new converter. It will charge but not nearly as quickly as it could. Otherwise it will work the same.
  • hmknightnc's avatar
    hmknightnc
    Explorer
    Jun 16, 2014
    smkettner wrote:
    If you never move you don't even need a battery except for a power outage.
    Single group 24 is fine for towing.


    X2, if it is always plugged in then your current converter and a single battery is fine. Just keep an eye on battery water level
  • snapper388's avatar
    snapper388
    Explorer
    Jun 16, 2014
    the new converter is power max 55 amp the old converter is wfco 45 amp
    I am using 1 group 27dc battery with plans to use 2 group 24's later. I live in the trailer and it is always plugged in.

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