Was up at Midnite yesterday and caught some load testing being done on video. This was actually a test of the battery breakers. There are 4 ganged up. Prior to this video one of the four was tripping prematurely. The remaining three held for a minute or so then of course they let go. This was a portion of the testing! Most brand X charge controllers when at or near full output will blow up/self destruct if the battery breaker trips.
The Barcelona did not self destruct even after multiple battery input breaker trips at 10kW 200 Amps. Mario designed it not to blow up under those conditions! One of the four ganged breakers was determined to be weak, and after replacing it the breaker held just fine during an 8+ minute test at or near 10kW 200 Amps. The "humming" you hear is the power supply feeding the Barcelona for the testing, not the charge controller itself. :)
Note: ETL will be at Midnite all next week putting the Barcelona through the grinder. If all goes as planned that means some BETA units will be going out the door soon....:)
https://www.youtube.com/watch?v=Q885tokyPX8