Electrical Assist - High Amp Trailer Charger?

[dragon_ram]

Looking for some electrical expertise. I have the 440a dual alternator option, but don’t have any toys to use them. I figure I can at least bump up my charge rate when towing.

1) what’s the max amp rate thru the 7-pin? I’ve read between 5-7a...
2) if I run 4 AWG from the batteries to the bumper, thru a connection to the trailer house batteries, what’s the fallout? Truck alternator going to become my battery charge controller?
3) is there a high-output battery charge controller that’s DC-DC that is a budget deal that could be added into the system?
4) any other ideas for the extra 300 amps I’m generating but not using? Disco lights and a 5000 watt subwoofer aside...

 

[carlrx7]

1) Depends how low the state of charge is on your trailer battery
2) Downfalls, another wire to connect and fuse. Power goes both ways, you will need a 4ga ground run as well
3) Renogy 40amp DC-DC charger is a good route.
4) put a 3000 watt nverter in your tool box... plug a/c cord in to the trailer. could probly run a small pancake a/c compressor too.

 

[jsalbre]

I’m running a Renogy 60a DC-DC charger on my set up.

I have 2ga running direct from the battery to a 300A continuous relay (ignition actuated) and then to an Anderson Powerpole connector at the rear bumper. 2ga ground is also going direct from the connector to the truck battery. Frame grounding is limited to 50a, and the DC-DC chargers can draw up to 50% higher amps input than output (that’s 90a on my 69a DC-DC). My trailer (Airstream) has the remaining 2ga run to the Renogy DC-DC which is mounted inside, then 4ga to my batteries (630A of LiFePo4).

My monitoring system shows right at 60A being put into my batteries when they need it.

 

[dragon_ram]

I’m running a Renogy 60a DC-DC charger on my set up.

I have 2ga running direct from the battery to a 300A continuous relay (ignition actuated) and then to an Anderson Powerpole connector at the rear bumper. 2ga ground is also going direct from the connector to the truck battery. Frame grounding is limited to 50a, and the DC-DC chargers can draw up to 50% higher amps input than output (that’s 90a on my 69a DC-DC). My trailer (Airstream) has the remaining 2ga run to the Renogy DC-DC which is mounted inside, then 4ga to my batteries (630A of LiFePo4).

My monitoring system shows right at 60A being put into my batteries when they need it.

Thank you!

How do you know frame ground is limited to 50A? I’m not doubting, just like sources. Seems there are some very high amp-draw amplifiers that just ground to chassis at point of install.

Reason you downgrade to 4ga post DC-DC charger?

Can I save costs using welding cable versus 2 or 4ga?

 

[jsalbre]

Thank you!

How do you know frame ground is limited to 50A? I’m not doubting, just like sources. Seems there are some very high amp-draw amplifiers that just ground to chassis at point of install.

Reason you downgrade to 4ga post DC-DC charger?

Can I save costs using welding cable versus 2 or 4ga?

The aux wiring kit with the truck says:

Ground Studs on the chassis/frame may be utilized as a grounding point with a 50A Maximum total load, see Vehicle Ground Locations section in the RAM Body Builder Guide, Electrical/Wiring Information.

I went to 4ga after the DCDC as the output is 60A and my run is only 3’. I used 2ga coming in because the draw is 90A and it’s running almost 30’

All of the heavy gauge wiring I used in this project (all the way up to 0000 for the inverter) Is TEMCo ”Welding Lead & Car Battery Cable” from Amazon.

 

[dragon_ram]

Thanks again - that’s gold right there.

 

[jsalbre]

Thanks again - that’s gold right there.

Happy to help!