Renogy DC-DC Charger UPDATE 2 Test
Update--fixed the problem below--you can skip to 4:06 pm post. Update 2- 28 Feb. My 20 amper is on, it has the green light and no red light. But it is cycling up and down for amps constantly, mak...
Forum Discussion
Found it! It was something to do with how the input and output neg terminals share the same chassis ground. I found 24ish volts across the output terminals, which is why it was cycling. :(
I swapped neg wires around until I hit upon a right way, and now it behaves.
Mystery how you can get 24ish volts with the positive wires the same way but just do whatever I did (don't know what I did) with the neg wires and get 14ish volts like it should.
With it finally working, with the truck running, I had 14.3 volts in the truck and 10.87 volts back in the camper at the DC inputs! (DC-DC will work down to 8 volts ISTR) That was using the 7-pin wires and no idea what the amps were on the input -maybe 25? Under 30 anyway since it was fused with 30a in Stud 1. Lots of voltage drop in those wires and connections.
Output was 14.1 and house batts 13.8ish, which would be going up over time to 14.7 (at the charger) with amps steady at 18ish in the Tri (so a 2a load +18= 20)
So it works and no amps tapering like with regular 7-pin. (down to 4.6 amps five minutes after starting the truck)
I swapped neg wires around until I hit upon a right way, and now it behaves.
Mystery how you can get 24ish volts with the positive wires the same way but just do whatever I did (don't know what I did) with the neg wires and get 14ish volts like it should.
With it finally working, with the truck running, I had 14.3 volts in the truck and 10.87 volts back in the camper at the DC inputs! (DC-DC will work down to 8 volts ISTR) That was using the 7-pin wires and no idea what the amps were on the input -maybe 25? Under 30 anyway since it was fused with 30a in Stud 1. Lots of voltage drop in those wires and connections.
Output was 14.1 and house batts 13.8ish, which would be going up over time to 14.7 (at the charger) with amps steady at 18ish in the Tri (so a 2a load +18= 20)
So it works and no amps tapering like with regular 7-pin. (down to 4.6 amps five minutes after starting the truck)
