Hi All,
My off-grid DC coupled system has three solar arrays, each with it’s own SmartSolar MPPT, Multiplus-II 48/5000/70 inverter, DC loads via SmartShunt, 7KVA generator, four Pylontech USB5000 batteries & Cerbo.
In situations where I’m topping up the batteries with generator power while there is sunlight available, all goes as I expect till the Pylontech’s get close to full & start limiting charge current. In this situation the MPPT’s shut off their outputs, and all charging and load currents are carried by the generator.
I can be in a situation where, for example, AC loads = 300W, DC loads = 1000W, Charge to the batteries = 50W, and the total of 1350W is being entirely drawn from the generator with the output of all the MPPT’s at zero, even though there is plenty of sun.
If I switch off the generator the MPPT’s kick back in & pick up the loads as expected.
It’s not necessarily a problem, just not how I expected the system to behave. I would have presumed it would prioritise getting energy from the MTTP’s if it was available to minimise generator fuel consumption.
Can someone shed some light on why it behaves the way it does?
Shalom
Bill