Moving battery to tongue

[DJD]

Originally Posted by CarlD

Bruce,


I do not know what your loads are, but I would run at least the same gauge as the existing wire. To keep voltage drop to a minimum a larger wire would be better. Sizing the correct wire depends on two factors, the load and the maximum acceptable voltage drop. If you use a 30 amp fuse on the battery, you should have a minimum wire size of 12 AWG.

I do not have extensive electrical wiring experience, but in my limited knowledge size 12 wag is intended to carry up to 20A. Size 10 wag is used for up to 30A in house wiring for clothes dryers, water heater. Since the awg is referenced, I assume (correctly or not) we are talking about the same size wire and the same definition of Amperage, regardless of the voltage system (12, 115, 230 aA). Conflicting advice is dangerous, so always reconcile with at least two more opinions.

[John in Santa Cruz]

the thing is, dropping a volt or two at 120V means only 1% or so of your power. Dropping a volt at 12V means 10%.

DC circuits used for battery charging, need to be very large gauge, as the battery is quite sensitive to the correct charging voltage.

Also, 30A at 12VDC is only 360 watts. high power devices, like an inverter, might need over 1000 watts, which is 80 amps or something at 12V.