DC-DC charger

[wyattamdahl]

I am connecting a Renogy 50amp DC-DC charger with MPPT. It is about 12 feet from my starter battery. I would like to connect the positive terminal of the charge controller to the positive of the house battery using 2/0 wire. I don't want to have to buy another 12' of 2/0 wire for the negative terminal. will something like 2awg work for the negative connection?

note: I do not feel comfortable wiring to the metal of my van and would prefer to stick to only wires.

https://www.amazon.com/gp/product/B07W84SS41/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[HRTKD]

Are you sure that device will accept a 2/0 gauge wire? A quick search shows the largest gauge it will accept is 4 gauge.

You don't need 2/0 for that amperage and distance. A 2% drop is possible with 6 gauge wire. I didn't use the chassis/frame for any of my wiring except for the ground.

 

[wyattamdahl]

Are you sure that device will accept a 2/0 gauge wire? A quick search shows the largest gauge it will accept is 4 gauge.

You don't need 2/0 for that amperage and distance. A 2% drop is possible with 6 gauge wire. I didn't use the chassis/frame for any of my wiring except for the ground.

I was going off of the amperage for the distance. I already have the 2/0 wire. would it do damage? or just be super extra?

 

[HRTKD]

The size (diameter) of the 2/0 cable means that it may not fit into the terminal hole in the device. You can't put a 10 mm diameter object into a 4 mm diameter hole.

This is all predicated on the type of terminal that is used on the device. Many inverters use a terminal that you insert a bare wire into and screw down the terminal to hold the wire. The other type has studs that require a ring terminal or cable lug.

I used your link and couldn't come up with a solid answer on which type of terminal it used. One question asked on that listing was the largest gauge that could be used and the answer was 4 gauge.

 

[wyattamdahl]

Both my inverter and my charge controller have ring terminal connectors.

 

[wyattamdahl]

I will likely use 4 awg wire to connect the negative end of the terminal. I will keep the 2/0 wire for the positive terminal. Will this be ok?

 

[HRTKD]

As long as you don't exceed the limits of the 4 gauge wire, it will work. Anybody looking at it will probably say, "WTF?"