Are my 12V Battery Cables undersized?

[E.S.P.]

Hi All,

I am curious if my battery cable wire is appropriately sized for my setup. My fifth wheel is described in my sig and it has a 30amp setup for shore power. It came with a single 12V deepcycle battery, but I opted for a second 12V when I took delivery. I've since replaced my battery cables to clean up the clutter of wires the dealer installed. I used #6 AWG wire for all the parallel connections and have not done anything with the original house wires that connect to the battery bank.

Questions:
1) Are the #6 AWG wires appropriate for the parallel connections.
2) Are the original house-to-battery wires OK having the second battery?

Sorry, but I can not remember off hand what the factory size wire is for the house connections. Just want to make sure my setup is safe.

Any advice is greatly appreciated.

[LadyWindrider]

Your house connections, aka shore power, is 30 amp, therefore 10 gauge wire. Thia has to do with the AC side of your trailer, Air Conditioning, Microwave, Converter, etc. It has nothing to do with the DC side of the trailer, where you will never pull 30 amps. #6 wire on the batteries should be fine. All you can run DC is the furnace fan, water pump, and lights. It also runs the electrics for the refer, and maybe a radio. No Air Conditioning, no Microwave.
Hope this helps.

[SaskCampers]

IF you installed the second battery for extra time then the house cabling is fine. If however you were putting an inverter of significant wattage (like 500watt or better) in the trailer using the existing cabling you will have issues. ANy large inverter should have the absolute shortest cables possible on the 12 volt side and be placed as close to the batteries as possible, the 115 volt output is fine over longer distances on 12 guage or so depending on the wattage of the inverter. Also how long are your 6 guage wires?

[E.S.P.]

Originally Posted by TheSasks

IF you installed the second battery for extra time then the house cabling is fine. If however you were putting an inverter of significant wattage (like 500watt or better) in the trailer using the existing cabling you will have issues. ANy large inverter should have the absolute shortest cables possible on the 12 volt side and be placed as close to the batteries as possible, the 115 volt output is fine over longer distances on 12 guage or so depending on the wattage of the inverter. Also how long are your 6 guage wires?

Yes, the second battery was installed for extra time and I do not have an inverter installed. The 6 gauge wires I have are only long enough to make the parallel connections between both batteries which are right next to each other; wires are roughly 12 inches or so.

From what I understand, as long as the worst case current draw on the batteries while running DC accessories does not exceed the amp rating for 6 gauge wire, I'll be fine. Anyone have an idea on worst case (refrig, television, concertone, lights, furnace, fantastic fan, H2O pump, gas detector, antenna booster, landing gear, slideout, etc..)? Obviously I would not be running everything at the same time or for very long, especially in a boondock situation.

[SaskCampers]

You will be fine with your intended use with the 6 gauge wiring. Do a searc on here or in google for the 12v side of life and there is a lot of good info. Also a few have posted current draw tables on here, I just cannot rmemeber where at the moment.

[E.S.P.]

Thank you for the help...I'll have to keep that article on hand for good reference material.