Wire size from battery to tow vehicle

[Bob Barnhart]

Hi all.  I am restoring a 1962 Mobile Scout 13'...11 without the hitch...fun size.   Anyway, I have heard that you need a heavier wire to run from battery to hitch so tow vehicle will charge the battery.  Suggestions?  We will be dry camping for the most part for short periods of time.  Only electrical other than 110 is 1 xenon and 4 lcd lights so battery usage is small.  May need charging for ipads etc and know I need an inverter for that.  Wiring camper now putting it back together.  Thanks in advance for any assistance on this and wiring in general.

Bob

[Jimco_W001]

Hi Bob,the usual trailer battery charge wire is 12 or 10 gauge.But you should run 8 or 6 gauge if you have a high output alternator and more then one battery.Also remember that if a appliance runs on 12 volts you should try and power it that way.Taking 12 volts and inverting it up to 120 volts just to reduce it back to 12 volts is inefficient considering the 10% loss when using a inverter.Jimco

[John "T" Nordhoff]

  Bob, Of course, the bigger wire you run the less voltage drop and more charging amps you can deliver into the trailers battery, but you have to consider practical issues and cost. That being said and figuring only one typical trailer battery, I wouldnt reccomend anything less then 10 Gauge wire protected at the source with a 30 amp self resetting circuit breaker. Dont leave the trailer still connected to the tow vehicle when camping, lest you discharge the tow vehicles battery ya know.

 

  A small lightweight Converter/Charger is typically installed inside the trailer so if youre plugged into shore power the 12 volt appliances are powered plus the trailer battery is charged. A small cheap 400 watt or so 12 VDC to 120 VAC Inverter can be used if theres a need to power a low power 120 VAC device for relatively short time periods. If youre dry camped not hooked up and only have one trailer battery (maybe 100 Amp Hrs), you cant run a whole lot for very long you know.

 

 To improve efficiency, run as many as possbile trailer loads at 12 volt. You can get LED or CFL lights, TV's, Cell Phone and I Pod etc devices that run or charge direct at 12 VDC (no need to waste Inverter energy).

 

 John T

[Bob Barnhart]

Thanks for the info.  I am installing lcd lights and after looking at usage may just leave the battery alone for now and see if I really need the extra access for charging.  Otherwise I will definately use the gauge wire you guys suggest.  Thanks for the assistance.