Its been a while since I have posted but ran into a question. A number of years back I setup a bank of deep cycle batteries (6x 115AH 12v) in parallel to run an inverter. The circuit being powered is connected to a 30 AMPS automatic transfer switch that on one side (shore/line) is my power provider and the other is an inverter. The inverter only requires a #2-AWG set of cables. And the load that it handles is a fridge, nothing to major <1000watt.

The setup has been working great and as designed for well almost 5 years now.

Lately I have been thinking about getting either a larger inverter or a second inverter to handle an additional circuit. My question is, if I up the power requirements of the inverter(s), can you simply add a second set of say #2-AWG cables on both the +/- sides of the battery bank to support the additional load, or would I have to go back and replace the entire wiring structure in the bank with a heavier gauge of wire? (obviously the gauge of wire would depend on the amp draw.)

I originally thought you would need to up the wiring size across the board, but after thinking about how twisted wire works maybe you can simply add additional wiring as desired (or is this the wrong thought process)?

 

Have a look at NEC 310.15(B)(2)(A)

http://www.houwire.com/products/technical/article310_15.html

 

Have a look at NEC 310.15(B)(2)(A)

http://www.houwire.com/products/technical/article310_15.html

Interesting, so it is possible. I would assume though you would want to match the cable length / size up accordingly as to match the resistance in the wiring?

 

I would assume that as well, but I'm not an electrician, so we're just a couple of laymen making assumptions.