Dashboard Alternator light

RLS7201 wrote:

BFL13 wrote:
So if that light on means the alternator is shut down, the only amps coming in are from the solar and batteries. Not many solar amps, so battery will run down but with the house batts also on line, that would take longer.

The solar controller would stay in Bulk but not be able to keep the battery voltage at 14.6 for long. What happens next?

In my test when the charger was removed, the voltage went back down to spec, but the light stayed on. I don't know if the alternator came back on. It did when I restarted.

Pretty simple. When the line voltage drops, the regulator does its job and sends voltage to the rotor winds and the generator goes back to work.

Richard

In my test, I was not able to tell if the alternator stopped charging when the voltage got to 14.99 and the engine stumbled but then kept running. The red light came on.

Then with charger removed , voltage fell to 13.8ish and the light stayed on. I think that means the alternator was on then, or voltage would have dropped to 12.x and not been 13.8ish.

So at that point the alternator was on but the red light was on too. I don't know if the alternator ever quit, or just got left behind on supplying amps to the loads when the charger's voltage got the battery higher than the alternator's.

Whatever, the OP wants max amps while driving at the proper voltage for his batts, which is high enough to make his red light come on.

He needs to test when that happens with the monitor set to read the amps to the house batts and not just read the voltage. He needs to see if the alternator is supplying amps added to the solar amps or not when that happens.

If not, then a Dc-Dc charger could help, where it isolates the alternator system from the house system, but still supplies amps to the house to add to the solar's amps, and it can be set to the same proper battery spec voltage as the solar's so they both add their amps fully.

Without them being at the same charging voltage, once the batts get to a higher voltage than the alternator's voltage, no more amps from that source.

If the RV has a gen that can be run while driving, then the OP could have three chargers on the house to bring them up faster like he wants, if he can set the charger run by the gen to the same voltage as the other two are at.

Refer to the thread(s) on how many amps of a DC-Dc charger can be used with how many amps the alternator is so it won't over-heat the alternator. In there is also the way to reduce the DC-Dc draw on the engine batt/ alternator by using fatter wire for the DC-Dc-input.

Also, get more amps by maxing out the roof space with solar if it isn't already.