Hi,
I have a small system in my rural cabin. 2 panels, charge controller, 2 batteries, inverter. Simple.
Where I live does not get much sun during the winter, and though I hope to set up some hydro soon, I recently got a small generator (with DC output) to keep the batteries charged. I also recently upgraded to a MPPT charge controller.
Using my old charge controller, I was able to hook the generator's DC output directly to the controller, to monitor the current coming into the batteries. I could see that it was putting out close to its rated 8 amps of DC current. However, when I switched to the MPPT controller, now when I hook the generator to it, the controller display shows only .2 (two tenths) amps coming in. I know this is not accurate, unless the controller is somehow limiting it.
I have done a bit of research on MPPT controllers, and I know that they expect a somewhat higher input voltage coming from the solar panels (typically about 17 volts), which they step down closer to the battery voltage in order to increase amps flowing into the battery (when the MPPT feature is functioning). I am wondering if the fairly consistent 12 volts coming from the generator (as opposed to 15-16 or more coming from PV panels) is somehow throwing the controller off.
Has anyone got any experience to share in this area? It seems that most systems are larger and more complex than mine, as generators usually go through some other component (like an inverter/charger) before hitting the batteries.
Any help or suggestions would be GREATLY appreciated. Thanks.
-Laz
