Solar + MPPT Charge Controller + Generator for night. Double check my setup idea?
I'm trying to design a power setup that can:
- Have Solar which charge batteries, when then power an inverter -> AC power
- Have a generator I can turn on to charge the batteries more during the night if they can't last
- Have this be as foolproof / maintenance-free as possible (no re-wiring or switching if possible)
- Power a constant ~400-500w/h
- Basically a double-conversion UPC with solar.
If you know ways to do this efficiently easily, definitely let me know. Below is what my assumptions are, then my current plan, and I would love input on mistakes I've made (bad assumptions) and ways to complete my setup.
After reading a lot of posts here, I've gathered:
- I can't just run the DC from my (Honda eu2200i) generator to the solar panel inputs on an MPPT controller, it'll blow the fuse on the geny
- I can't run the Honda on Eco-Mode during DC production
- If I do the DC (12V 8.3A) from the Honda, I'll have to use a step-up converter to convert it to the correct voltages / amps for my battery bank (ideally only do the bulk charge), then connect it to the batteries in parallel w/ my charge controller.
- If I do AC from the Honda, then I can have it in Eco-Mode, and I can use a simpler AC battery charger (again, maybe only bulk mode so I don't waist gas on the absorb mode), and again in parallel w/ the mppt charge controller. AND this shouldn't blow the generator - hopefully the AC charger will have max amps & can shut off?
- I basically can't connect the honda to the mppt charge controller directly.
- For all of these setups, I can be using the 'load' terminals from the mppt charge controller just fine (even though I maybe be charging from the geny -> AC charger -> batteries
Assuming all of those are correct, I'm guessing my setup would be as follows:
- Solar Panels, in series, where the voltage is appropriate for the mppt controller and and the batteries (12V batteries, so >18V from the panels). Calculate # based on watts, and if I can recharge the batteries during the day during the additional load (extra to be safe)..
- MPPT charge controller that can handle the amps I need to output (probably 40 or 60).
- Lead-acid batteries that last me all or most of the night.
- A decent 1000w inverter (for my power load)
- A decent AC charger (unknown exactly what to get here) for generator -> batteries
- Wiring would be: panels -> mppt -> inverter -> load, geny -> AC charger -> batteries, batteries <-> mppt
- Does this sound right?
- What might go wrong?
- Any product suggestions?
- Is it alright that have the load output from the mppt controller, even if solar is generating no power & I'm charging the batteries from the generator?
After finishing this project I'm planning on documenting how I did it for others... definitely a steep learning curve here. I can share my planning doc as well.