It's a 20 ft run to the batteries ..
Okay that means the converter wiring has a 20 ft or more run to the batteries
What size is the wire?
Is it bigger than what you bought?
Is it 6 gauge our is it 10 gauge ?
What size did you buy for this run?
Once the wire leaves the controller, it's at charging voltage, the longer the wire the more voltage drop, the smaller the wire the more voltage drop
In 99% of the time, there is loses that could have been avoided,
10 gauge wire is rated for 30 amps at 120v
But at 14v charging it will have too much voltage drop, and the batteries will rarely reach full charge..they will if the camper is not used for several weeks, but they won't when the camper is being used
Voltage drop means slower charging
