Doubled up my 4/0 cables

[corn18]

I moved my batteries under my front bed in the 5er so I could add more batteries. That resulted in the run from the batteries to the loads going from 1.5 ft to 10 ft. Calculators said 4/0 was fine for max load of 325A. I was working on the 5er the other day and had a single 15k BTU aircon on for an hour and the 4/0 cables were getting warm. Not hot, but warm. Didn't have my IR thermometer to check actual temp.

I looked for a closer place to put the three 12V 206Ah SOK batteries but nothing was available. And I have a 4th SOK battery on the way. So I decided to double up the 10 ft 4/0 cable. Ran a single 15k BTU aircon, refrigerator, fan and TV (with Dolby 5.1 sound system) for 4 hours and the wires stayed ambient. Maybe just a little warmer than ambient. Really happy not to be wasting my Ah on heating cables.

The batteries go to a Lynx with equal length 2/0 cables. Negative output has a Victron shunt mounted directly to the Lynx. Positive output has a 400A type T fuse mounted directly to the Lynx. I just doubled up the lugs for the 4/0 cable on the shunt and type T fuse. I am good with that.

I used a 1/2/1+2 Blue Sea Systems 600A cutoff switch attached directly to the Lynx distributor input. That way I didn't have to double up the 4/0 positive cables. I tripled up on the negative input to the Lynx (2x4/0 return to batteries and 1x4/0 chassis ground) and don't like that. I think I have a 600A Blue Sea Systems bus bar laying around so I might hook it directly to the input to the Lynx distributor and bus the three 4/0 cables.

Calculators say I am over cabled now with a 1.59% voltage drop vs. 3.19%. I like it.

[corn18]

This looks a lot better I think.