I have fitted another 140watt poly crystalline panel to the camper for a total now of 380 watts , Yesterday (sunday ) was a really good solar day and the panels were pumping 15volts. When driving the solar panels were fooling the campers alternator through the VSR and triggering the indicator light until just above idle and dropping the start battery voltage . Has anyone experienced the same problem or do I just fit a 12/12 v DC charger .
Sorry Denis, I have not experienced the problem you are experiencing, but can easily see how it is happening.
Once the voltage in your starter battery is high enough the VSR switches on, and the higher voltage of the solar is enough to fool your alternator (I guess you already knew all of this).
What options do you have?
1. Install a DC to DC charger (expensive).
2. Fit a large diode to stop the voltage from the house battery flowing back through the VSR.
I would definitely favor the second option, cheaper, and simpler, thus less to break.
If you have a 2nd Battery then install a smart Battery Isolator....
They should stop the back flow of the excess voltage....
--- also what is the Voltage of battery when it's full charged... If it 2 high, you could be Over-charging the Battery.... causing the issues to the batteries Life....
Juergen
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Hi juergen, the solar is charging at 15 volts unloaded which from all accounts is ok as the AGM batteries need 14.8 + volts to get to optimum , the alternator is regulating at 13.9 which is not enough for the AGM`s . the only trouble with the diode option is the voltage drop across the diode . I think the dc/dc charger is the go.
