Eco-worthy 20a MPPT controller

Salvo wrote:
Thanks for the testing. The 0.1A gain compared to direct charge does seem quite low; especially when battery is at 12.5V. Is the controller's operating current high that it impacts your measurements? Perhaps using a panel that's greater than 100W will provide better results.

Sounds like there's a relay in your controller. It may be measuring open circuit voltage of the panel. Time to pull out the scope.

Sal

There is no relay in there. The clicking is faint and sounds more like the oscillator driving the inductor in the buck circuit is turning off. Don't know if they're taking a measurement during that time, or it's an interrupt being handled by the PIC to do something else so they have to turn off the PWM output or what.

I have not measured quiescent current draw of the unit 'officially' but the clamp on meter which has 10mA resolution is showing 20mA draw during standby/snooze.

Yeah, probably not so great due to me operating it really low in its power handling capability. I do have 2 qty 45W panels though I'm only using one right now, but one of the tests I want to do is compare the charging amps with the panels in parallel vs in series going through the MPPT controller, and also vs in parallel going through a PWM controller or direct to the battery.