Charging batteries with Rectified Generator output?

[Murby]

Had a bit of a strange idea.. for emergencies but just wondering...

If one were to take a small generator and hook up a rectifier to the output to turn the 120 vac into 120vdc, could that be used on the input of a Flexmax80 controller to charge batteries? Would an Outback Flexmax care that its pulsed DC current instead of straight DC from solar panels?

[NEOH]

Yes, the Outback would "care".

A PV Panel
1) is more like a "Current" Source at Higher Amps
2) is more like a "Voltage" Source at Lower Amps
3) has a Peak Power Point at the transition between the two above modes

A Generator is a "Voltage" Source.
The Circuit Breaker on the generator would probably trip due to MPPT.
Ask yourself ... Where is the Max Power Point for a generator ???

[SunEagle]

What NEOH states is true. A solar charge controller requires a "current" source to work. Any type of DC power supply will not provide that except for solar panels.

[Murby]

So if I understand what you guys are saying, the problem is that the charge controller will hunt for the maximum power point by continuously dropping the input resistance to find out where the maximum current flow is at... and since the generator, by its nature, will just keep the same voltage and continuously send more current, the process will run away until either the charge controller blows or the generator's breaker trips.

Did I get that right? So the charge controller is going to continuously allow more and more current until it sees a slight voltage drop, at which point it thinks it has reached the MMP??

[ButchDeal]

Luckily the outback inverter doubles as a charger so yu don,t need to do anything like this. Just feed the generator into the inverter/ charger..

[NEOH]

Yes, the MPPT logic searches for the Maximum Power Point.
That is my story and I am sticking to it.

Your explanation how the Charge Controller actually searches for, finds and "follows" the Max Power is utlra-simplified.
There are a couple of different MPPT searching techniques, but basically you are correct.
Don't forget that the MPPT logic must find the Max Power Point from both directions - from "below" the peak and from "above" the peak.

Also, if your Rectified DC is not smoothed, then the pulsing could really confuse the MPPT logic.

[Murby]

Luckily the outback inverter doubles as a charger so yu don,t need to do anything like this. Just feed the generator into the inverter/ charger..

Yes, I'm with you on this.. But, as is my nature, I have to explore every stupid little corner so I know what my limits are.. If there's something I'm not familiar with, I'm not comfortable or satisfied.. its probably some personality defect or something..

[Mike90250]

Had a bit of a strange idea.. for emergencies but just wondering...

If one were to take a small generator and hook up a rectifier to the output to turn the 120 vac into 120vdc, could that be used on the input of a Flexmax80 controller to charge batteries? Would an Outback Flexmax care that its pulsed DC current instead of straight DC from solar panels?

NO. the ripple would be too bad. the MPPT controller would not like the poor impedance of the generator.