Jeff Hagen on a Facebook forum also mentioned.
The max input for the AC200Max’s built-in MPPT controller is 900 Watts, not 1200 Watts.
The DC Charging Enhancer can support an additional 500 watts of solar, not 200 watts.
The voltage going into the DC enhancer does not affect the voltage going into the built-in controller. They are totally separate circuits with their own limits. You can run the built-in controller at up to 145 volts and it will pull up to 15 amps. You can also run the DC charging enhancer at up to 60 volts simultaneously. The DC charging enhancer can pull up to 10 amps.
This scales across attached B230 and B300 batteries and allows much more power as shown. The below diagram was confirmed by Bluetti’s customer service as a valid solar setup for the AC200Max.
When you add solar panels in series, you multiply the Voc of each panel by the number of panels in series to determine the Voc of the entire string of panels. Each controller should have all-identical panels on that controller.
Bluetti PV200- Voc is 26.1 volts. If I use 5 of them in series then the Open Circuit Voltage for that string of panels is 26.1v*5 = 130.5 volts
Since 130.5 is less then 145v, it is OK to use 5 panels. Yes, that is rated at 1000w where the controller will only pull 900w. It “wastes” a little bit at max output, but it also means it will get to max output faster. This is known as “overpaneling” and is generally considered a good thing.
If you are going to be in an environment that goes below freezing, increase the rated Voc of the panels by 10% in your calculations. Solar panels make extra voltage when they get really cold. In my case, it never goes below freezing where I live. I went with the rated voltage directly and will do so for these examples.
If I wanted to use 8 panels in series then the then the Open Circuit Voltage for that string of panels is 26.1v*8 = 208.8 volts
Since 208.8 volts is greater then 145v, it is not OK to use 8 panels in series.
Note that the voltage is calculated per MPPT controller. The DC Charging Enhancer has a max of 60v / 10amps. This 60V does not impact the max voltage of the built-in controller.
If I use the PV200 panels as an example again, it means I can use 2x PV200s in series to a DC Charging Enhancer and also use 5x PV200s to the built-in controller on the same AC200Max simultaneously.
The image below has 4 MPPT charge controllers: 3 are the D050S DC Charging Enhancers and the other one is the controller built into the AC200Max.
Each controller is unaware of what panels are plugged into the other controllers. Each controller only cares about panels plugged into itself.
You can have one controller with a single (or many) 200 watt panels and another controller with a 350 watt panel. No problem there.
As long as the voltage on each controller is less then the maximum for that controller and all panels on the same controller are electrically “the same” then you are good to go.