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NRALIFR
Explorer
Jun 22, 2018

Redarc DC-DC Battery Charger

I’m in the process of installing a Redarc BCDC1225D battery charger in my truck camper. I got it installed enough yesterday to give it an initial test, and was pleased to see that with the truck idling, a little over 20 amps was flowing into the battery according to the Trimetric panel. It’s rated for a maximum of 25 amps.



The Redarc charger works similar to a solar controller, taking DC voltage from the truck batteries and alternator that normally would be less than ideal for charging, and boosting it up to 14.6, 15.0, 15.3, or 14.5 depending on which charging profile is chosen based on battery type. In fact, this particular charger has a built-in MPPT solar controller and an input wire that can be connected to a solar panel.

Heavy cabling is still required in order to get the rated charging current from the Redarc charger. I have 4 AWG welding cables run from the truck batteries to a 2-Pole Pollak Connector in the front of the truck bed. From there, the 4 AWG wires continue through the camper umbilical cord directly to the TC battery, with the +12v wire running through the Redarc charger first.

For some reason, Lance had the 12v wires from the umbilical cord running to this low voltage panel first, rather than directly to the TC battery. This added several feet of extra wire to an already long run, and was limiting the amount of battery charging I could get from the truck. On our last trip with the camper, one of the screws on the ground bar on the right loosened up and got hot. The screw was for the -12v wire from the camper umbilical cord, so the TC battery was getting almost no charge.



Due to the cramped quarters and limited amount of space available to mount the charger, this has been a major chore to install. Routing the wires from where the umbilical cord enters the camper to the battery box and Redarc charger required removing the water heater in order to get the wires under and to the side of it. This is where it’s going to sit in the cabinet under the galley sink. The battery box is to the left of the Redarc, behind the panel with the bus bar on it.



While the water heater is out, I’m also taking the opportunity to make a couple of other changes that couldn’t be done with the water heater installed.

I prefer to run the fridge in AC mode from an inverter while on the road. I put a battery charge meter on the front of the camper several years ago so I could keep an eye on the battery voltage. The meter just has a series of red/yellow/green LED’s that I can see in my side mirror, and since it’s not displaying digits, it doesn’t matter that I’m seeing a reverse image in the mirror. I don’t really need to know the precise voltage, I just need to know if the state of charge is going up or down. Between the charge meter, and a wireless thermometer I have in the fridge, I can tell when the fridge cooling unit is on or off, and if the camper battery is getting some charge current from the truck. .



When I first installed the meter, I was hauling the TC on a ‘95 F350. I put it in the hole on the right. When I got an F450, because it’s wider I had to add some extensions to the swing-out brackets on the front jacks, which made them swing in further and cover up about half of the charge meter face. I moved it to the left a few inches, and I’m planning to install a waterproof remote switch for the inverter in the old hole. The old remote switch was inside the battery box, but it will be more convenient if it’s in this location.

This is what’s under the water heater. I’ve cleaned this area up a lot.



I still have some work to do before I can put the water heater back in. I have a new battery disconnect switch ordered, and it will be easier to install If the water heater isn’t there.

:):)

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