Small dc to dc charger on existing wires

[SteveT90]

I've seen posts where people put in 20 or more amp dc to dc chargers in their trailer to charge the trailer battery while towing. But a 20 amp charger draws twice that on the input side as I understand it (so 40 amps), and the fuse and wires on the bargman cable have a max of 30 amps, so for a 20 amp charger you have to install new thicker wires and bigger fuse.

But I don't want to install new wires. So my question is, has anyone installed a small 10 amp dc to dc charger in their trailer, on the existing wires in the vehicle and the bargman cable, using the existing 30 amp fuse, anrd does that work?

If I could get close to 10 amps charging, that's all I need. Right now with the stock setup, I get only about 2 amps charging, and thats only when the trailer battery is discharged quite a bit.

 

[fourwd1]

As this is not generation specific moving to General Discussion.

 

[Mgyver1]

Victron makes an 18a DCDC charger (model 12/12-18) and Redarc makes a 12a DCDC charger specifically for trailers model BCDC12T).

 

[shadow247]

Victron makes an 18a DCDC charger (model 12/12-18) and Redarc makes a 12a DCDC charger specifically for trailers model BCDC12T).

good info! I'm looking to add pass through power to my camper, and this is exactly what I needed!

 

[Ronswines2]

What gauge is the AUX-12V Power line (red wire) in the 7-way trailer connector on 5th Gen T4R?

 

[glenhansen]

I've seen posts where people put in 20 or more amp dc to dc chargers in their trailer to charge the trailer battery while towing. But a 20 amp charger draws twice that on the input side as I understand it (so 40 amps), and the fuse and wires on the bargman cable have a max of 30 amps, so for a 20 amp charger you have to install new thicker wires and bigger fuse.

But I don't want to install new wires. So my question is, has anyone installed a small 10 amp dc to dc charger in their trailer, on the existing wires in the vehicle and the bargman cable, using the existing 30 amp fuse, anrd does that work?

If I could get close to 10 amps charging, that's all I need. Right now with the stock setup, I get only about 2 amps charging, and thats only when the trailer battery is discharged quite a bit.

Yes, you can install a 10 amp DC to DC charger in your trailer using the existing wires and 30 amp fuse on the Bargman cable. Since a 10 amp charger will draw around 20 amps on the input side, it should work within the 30 amp limit of your existing setup. This should significantly improve your charging rate compared to the current 2 amps you’re getting with the stock setup. Make sure to verify that all connections and existing wiring can handle the increased load safely. Retro Bowl

 

[trainman605]

After having a couple of different travel trailers over the years, this charging question has been around for as long time. The answer has always been, change the power wire from the vehicle thru the plug to the trailer. Charger wire should be a #12/#10 wire, in most cases the vehicle and trailer wires are too small to do much good to charge the trailers batteries correctly.