Mtodorov

I'm not comfortable with making it lower than the factory value of 90V, but yes, if you have a short string on an MPPT, then you would probably benefit from the minimum MPPT voltage staying at 90V. So I've made a 90V version. You'll have to delete dsp.hex (it's the 150V version, since I expect that to be the most commonly used variant), duplicate dsp_964.62_patched_90V.hex, and rename the result  to dsp.hex. If you had the '28066 model, then you'd get the newer reflash tool which can pick any hex file from a list (advanced! :-O).
Please let me know how it goes.
 
These are patched firmwares version x64.62 for the Axpert Max E 11kW Twin with the '2809 DSP chip, based on factory firmware version 64.62. Do not use with any other model. Read the "Readme patched versions.txt" file for how to choose one of the three patched firmware variants, or to revert to the factory firmware. Use at your own risk.
The patched firmwares implement all of Georg594's original patches, although one patch (for each MPPT, so two total) could not be exactly applied. I've applied it as best I can "in the spirit" of the original patch. It also fixes the premature float bug, and changes the version number reported by monitoring software to x64.62.The current threshold is changed from 0.50 A to 0.05 A, and the minimum MPPT operating voltage is changed from 90 V to 200 V / 150V / unchanged (90V).
The 150V and 200V patched firmwares in this file are the same as released earlier.
Firmware upload instructions for models with a removable display.
dsp_x64.62_patched_200V_150V_90V.zip