Trailer Battery

c5hd · January 6, 2004

How are you guys wiring your trailer Batteries?

It seems to me that the wire in the trailer harness is far to small (10 -12 gauge?) to support those kind of amps. Especially with the distance from the charging system, I would imaging you would need at least 2 or 4 gauge. Am I missing something?

I assume a deep cycle battery is preferred, any recommendations (size/brand)?

Any tips/tricks, suggestions are welcome.

Thanks.

Shaners · January 7, 2004

I used the stock 7-prong plug on my truck and it seems to work fine. I'm pulling a 32' travel trailer, and one time the battery was dead on the trailer, but the truck supplied enough juice to work the lights and the slide-out.

It's a good thing the hitch didn't come apart though because, the trailer brakes wouldn't have locked up!!!

Delaware · January 7, 2004

I also use the stock 7 pin plug with no problems. Battery has always stayed charged. The battery is the stock one that came with the TT.

BlackSilver · January 7, 2004

I use the stock 7-position plug, and it works fine. Battery is a size-31 deep cycle.

Never had a hint of a problem.

THE BIGPUNN · January 7, 2004

i agree, guage stock seems fine

bomber · January 7, 2004

10-12 ga is plenty for DC Household AC current takes solid larger wire.

Depending on your needs you can wire up a 2nd battery with a solinoid to keep it from drawing from your vehicle if it's a camper or such that doesn't have it's own battery.

hosspuller · January 8, 2004

Disclaimer: Am Not electrical engineer..

Amps is Amps. 10 gauge copper wire is okay for 30 amps. at 12 volts or 120 volts. More if you don't mind voltage drop and heating.

DC will require larger switches and contacts because of the arcing. AC current is easier to break since the current & voltage go to zero twice at 60 Hz.

c5hd · January 8, 2004

Thanks guys. I want to add a second, large battery (not the little one for the brakes) to power lights and stuff when the trailer isn't connected. Sounds like I am good to go.

MemphisDoug · January 8, 2004

I believe that wire is actually rated for the power that it will handle. Power is equal to volts x amps. Therefore, the same size wire will handle higher amperage for 12 volts vs. 120 volts. 10 times more to be exact. If wire was rated only for amperage, think about the guage of wire you would need to handle the 100 amp output of your alternator! This is why you see relatively small guage wire handling high amperage conditons at 12 volts.