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 idlin...
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That’s true, and is one factor that caused me to choose the 25 amp charger vs the 40 amp charger. Price was definitely a factor, too.
The 4 gauge wires were already on the truck before I bought the Redarc. I had intended to replace the 8 gauge wires in the camper umbilical, but hadn’t gotten to it yet because the water heater was in the way.
The length of the circuit from the truck batteries to the Redarc charger is about 25 feet, and according to the wire sizing recommendation in the install guide, the 25 amp charger required 6 gauge wires minimum for that length, and the 40 amp charger required 4 gauge minimum. I wanted to over size the wires if possible, so I stuck with the 25 amp model. Plus, it was about $60 more for the 40 amp charger.
So now after replacing the wires in the camper umbilical cord, I have a 4 gauge circuit from the truck batteries to the camper battery, and the Redarc is sitting just outside the battery box as close to the camper battery as possible. The +12v output wire from the Redarc goes straight to the positive post on the camper battery. It doesn’t even go through the battery disconnect switch because the Redarc charger doesn’t back-feed 12v from the camper battery to the truck. The -12v wire goes to the load side of the Trimetric shunt, which is inside the battery box next to the battery.
The cables were all cut to length, the lugs crimped with this tool and then soldered. I have a CB on the truck end, and the recommended 40 amp MIDI fuses on the Redarc input and output wires. All that is to say that I think I have it installed with adequate margin to handle continuous output at full rated power, which it’s rated to do up to 130 degrees.
When we’re traveling and running the fridge from the inverter, I set the fridge thermostat on one of its lowest settings so the cooling unit runs just enough to maintain a safe temperature. That’s where my LED meter on the front of the camper and the wireless thermometer come in handy. If I set the thermostat too high, the cooling unit just runs all the time, and the camper battery slowly looses ground.
Before I installed the Redarc, the charging circuit to the camper battery could ALMOST keep up with the drain from the inverter. We typically would end the day with the camper battery at about 85-90% on the Trimetric. And that was even with the wires in the camper umbilical still being 8 gauge, several feet longer than they are now, and running through that low-voltage panel with the hinky loss-inducing connections.
It should work better now. Much better, I hope. In fact, it may work well enough now that I could try running the fridge in DC mode again, and eliminate the inverter loss. The DC heating element in the fridge is only 215 watts though, and it couldn’t keep up when the ambient temps are above 85 or so. It would end up just running 100% of the time, the fridge slowly getting warmer, and leaving the camper battery in worse shape than AC mode. I’ll try it again though.
:):)
The 4 gauge wires were already on the truck before I bought the Redarc. I had intended to replace the 8 gauge wires in the camper umbilical, but hadn’t gotten to it yet because the water heater was in the way.
The length of the circuit from the truck batteries to the Redarc charger is about 25 feet, and according to the wire sizing recommendation in the install guide, the 25 amp charger required 6 gauge wires minimum for that length, and the 40 amp charger required 4 gauge minimum. I wanted to over size the wires if possible, so I stuck with the 25 amp model. Plus, it was about $60 more for the 40 amp charger.
So now after replacing the wires in the camper umbilical cord, I have a 4 gauge circuit from the truck batteries to the camper battery, and the Redarc is sitting just outside the battery box as close to the camper battery as possible. The +12v output wire from the Redarc goes straight to the positive post on the camper battery. It doesn’t even go through the battery disconnect switch because the Redarc charger doesn’t back-feed 12v from the camper battery to the truck. The -12v wire goes to the load side of the Trimetric shunt, which is inside the battery box next to the battery.
The cables were all cut to length, the lugs crimped with this tool and then soldered. I have a CB on the truck end, and the recommended 40 amp MIDI fuses on the Redarc input and output wires. All that is to say that I think I have it installed with adequate margin to handle continuous output at full rated power, which it’s rated to do up to 130 degrees.
When we’re traveling and running the fridge from the inverter, I set the fridge thermostat on one of its lowest settings so the cooling unit runs just enough to maintain a safe temperature. That’s where my LED meter on the front of the camper and the wireless thermometer come in handy. If I set the thermostat too high, the cooling unit just runs all the time, and the camper battery slowly looses ground.
Before I installed the Redarc, the charging circuit to the camper battery could ALMOST keep up with the drain from the inverter. We typically would end the day with the camper battery at about 85-90% on the Trimetric. And that was even with the wires in the camper umbilical still being 8 gauge, several feet longer than they are now, and running through that low-voltage panel with the hinky loss-inducing connections.
It should work better now. Much better, I hope. In fact, it may work well enough now that I could try running the fridge in DC mode again, and eliminate the inverter loss. The DC heating element in the fridge is only 215 watts though, and it couldn’t keep up when the ambient temps are above 85 or so. It would end up just running 100% of the time, the fridge slowly getting warmer, and leaving the camper battery in worse shape than AC mode. I’ll try it again though.
:):)
