Interaction of Solar and Alternator
My camper has a single 100W roof-mount panel, which meets my power needs (2 @ 6V batteries) when the sun shines. However, when camping among trees for several days it is easy to consume 70 to 100 Ah ...
Forum Discussion
With the monitor for your ammeter, it is easy to do some tests parked in the sun.
With the batts near full, just turn everything on in the camper and get as many amps draw as you can, say minus 20 amps. Now with no solar, turn on the engine and see what the amps do. Might be minus 5, so charging is 15 amps. Wait a few minutes and those amps will taper as voltage falls to 13.x. Might then only get 8 amps charging.
Same with solar and no engine on. Now you get your 4 amps solar, so amps go to minus 16.
Now turn on engine and see what happens to the amps.
If the charging amps go above the draw the diff still works with a few positive amps showing.
With the batts near full, just turn everything on in the camper and get as many amps draw as you can, say minus 20 amps. Now with no solar, turn on the engine and see what the amps do. Might be minus 5, so charging is 15 amps. Wait a few minutes and those amps will taper as voltage falls to 13.x. Might then only get 8 amps charging.
Same with solar and no engine on. Now you get your 4 amps solar, so amps go to minus 16.
Now turn on engine and see what happens to the amps.
If the charging amps go above the draw the diff still works with a few positive amps showing.
