Greetings,

Thanks again for your quick response. The complexity appears to surround the fact that the AC200 functions as both an electric supplier and an electric user. Consider the AC200 connected to a TV. In this case the AC200 has the ability to generate 20A, at 110V but the TV’s internal resistance limits the current to 2A. In this case the system only uses 2A, 220W. Here, the TV is the item which determines both the amps and watts.

Point here, is that in all systems, generators produce voltage, and receivers determine the amps and watts used.

When charging, the panels are the generator, and the AC200 is the receiver. If a 50V panel is connected to the AC200, the AC200’s internal resistance will limit the amperage to some unknown figure, say 4A. In this case, the system will utilize only use 4A and 100W. That means, you would want to purchase a 50V, 120W solar panel. Purchasing a 50V, 300W solar panel would be a waste of money, because the AC200 may not be able to utilize the extra wattage. (But the 50V, 300W panel would be wonderful if the AC200 allows 12A at 50V.)

In most situations, the ratio of volts-to-amps is fixed, so understanding that ratio would be very useful when buying solar panels. It is possible, that the AC200 has a computer that is able to alter the volts-to-amps ratio, which is why I asked for data for 50V, 75V, 100V. (By the way, the volts-to-amps ratio is called “resistance” and it is measured in a unit called “ohms.”)

The fact that Bluetti sells a 35V, 120W panel suggests the volts to amps ratio is around 10V to 1A. This matches my estimate the the sweet spot is 100-120V.

Sorry this is a bit heavy, but I’m trying not to purchase excess wattage. Thanks for your help.

Yours, Duane