AC300 - Need Clarification Maximum PV Current & Power Input Please

Product Discussion BLUETTI AC Series
1

Hello there!

I’m sure this technical question has been asked many times, but I’m hoping I can obtain a definitive answer prior to installing a Solar array as PV Input for my Bluetti AC300.

Specs say dual MPPT inputs, 150 maximum maximum volts, and 1200 watts maximum power, each input.

I was thinking of stringing for each PV input, three max open circuit 40.7 PV panels in series (122.1 max volts / 10.76 amps max output current) and paralleling a second set of three panels, which would equal a max combined PV output of 122.1 volts / 21.52 max amps output, or 2628 max watts of available PV power output. My Solar tech tells me this will exceed each of the AC300’s max PV inputs of 1200 watts, and damage the unit.
My understanding is that the Bluetti’s MPPT will regulate input current based on input voltage, ensuring the maximum power input of 1200 watts is not exceeded, with any excess power available from the Solar Array simply remaining unused. Otherwise, under typical seasonal, time of day or weather related lower light conditions, it would seem to me that one would rarely achieve the ideal voltage / current / power conditions and obtain anything close to the rated 1200 watts PV input.

Basically my installer is telling me I can only hook up a maximum of 3 40.7 max volt open circuit /10.76 max amps panels in series per PV input, in order to meet the maximum voltage, current and “power input” specification. That would be the absolute maximum power out available from the combination of three panels, under perfect high light conditions. Otherwise, my installer suggests paralleling a second string of three panels will input far too much current / power, and fry the MPPT controller.

Looking for clarification on this point prior to installing and configuring my Solar Array.

Cheers!

2

Input current will be limited automatically but you are talking about voltage which is not current. Voltage cannot exceed the 150 volts which is why your installed is stating your max is three panels rather than four which would put you in an over voltage situation.

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3

Thanks for the reply Scott.
Sorry, I don’t see in my post saying that I’m wiring 4 panels in series, I stated 3 panels in series equaling 122.1 volts max open circuit, paralleled with another three, (122.1) volts, which would supply 122.1 Volts / 21.52 amps max from a six panel array.

My understanding that as far as current is concerned, the MPPT will “pull” the necessary (and max) current from the PV supply based on input voltage, rather than the PV array “pushing” current into the Bluetti. As long as the max open circuit voltage is under 150 Volts, no issues. Correct? The Bluetti MPPT will limit current draw as necessary to achieve the maximum 1200 watt rated input power? My tech is telling me that the 21.5 amp available current from this configuration will fry my MPPT Controller because it is rated at a max 12 Amps. He is multiplying the max 122.1 volt output and the 21.52 amp maximum available current from this 6 panel array, and arriving at a total input power of 2628 watts, which exceeds the 1200 watt rated input power of each MPPT input and damage will occur as a result. I don’t think that is correct, hence my post.

4

Correct as long as the max open circuit voltage does not exceed 150 then you are good to go. But…I would go no higher than 135 to 140 because the stated voltage can increase in very cold temps. This will give you a little buffer. If you live in a warm climate, no issue. You can get closer to the 150 volt cut off.

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5

Thanks a million Scott, your response is greatly appreciated sir!