Installing 2 PMU-16 in my car.

I working on rewiring my car right now. I decided to go with 2 PMU-16 one to control stuff with the engine and one to control all the lights and wipers. I was wondering what size cable do you normally run for the main power from the battery. I was originally thinking a 4AWG wire but not sure if that will be enough.

They state -

OUTPUTS

High current outputs

10 x 25A(cont.), 6 x 15A(cont.) with overcurrent and overheating protection. Outputs may be paired to increase continuous current capability. Current and voltage is measured for each output

Total current output

150A continuous

Output current control step

100mA

Wipers output

Dedicated output with wiper braking feature

+5V

Monitored 5V, 500mA output for powering external sensors.

A "4" AWG cable is good for ~75A depending on length, acceptable voltage drops, heat buildup, etc - https://www.powerstream.com/Wire_Size.htm - which 'might' be fine if you know what is going to be powered by the PMU(s), but perhaps a "0" gauge would be safer and minimise power loss through wiring voltage drop? Personally, I tend to upsize anyway when looking at power circuits, as the potential power supplied drops with the square of the voltage - ie, 10% voltage drop means 19% power loss, and 20% voltage drop (eek!) means 36% power loss. With some things, like on-off switches, this may not be as important as other things, like motors and other high draw devices.

I'm with Gord. I'd do as they suggest or go a little bigger. I tend to go a little bigger because I end up adding things later.

Thanks guys for the information. Going a bit bigger than needed is a good idea. Just trying to figure out how I'm going to run 3 1/0 cables off my battery terminal. Since the cable is only going to run inside the car try and find something with good protection with a small outside diameter.

You should be able to find a suitable bus-bar easily enough.

Failing that, check out what the ICE competition guys use for their multiple amplifier setups.