features for dc to DC chargers

S Davis wrote:
The Redarc 40 and 50 amp dc to dc chargers have a built in solar controller that use solar charging first and then supplements with alternator charging, might be a useful feature for some.

Does the manual explain how it does that? If so I will read it, no need to write it up here, thanks.

With no DC-DC in the Class C, I get solar and alternator to add their amps, but with the solar set at 14.8v and the alternator at say 14.0v, I don't get all the alternator amps there are.

Example rough figures-- Turn off solar and get 20 amps alternator charging as seen on the Trimetric. Get 20 amps solar, engine off. Turn on engine and get 40? Nope. Get about 30 total. The voltage spread from battery to 14.8 is more than from battery to 14.0 so the alternator amps are already tapering from shrinking spread as they both raise the battery voltage. Once the battery reaches 14.0 all the amps are from solar.

(The battery bank has to be low enough to accept the total possible amps at the time or you can't tell if the 30 is just from that being the max acceptance)

So that Redarc is doing something like that too, but where it is the one with two inputs at different voltages, not the battery itself --or what? It must have just the one voltage for output, but two different input voltages?

If you already have solar, do you swap over to the Redarc controller or are you better off staying with the one you have? Depends I suppose.