How to fix ICOM A2 voltage 11.33 error message

When I use BMW ICOM A2 diagnostic tool to do programming, car engine off go on and shows lower voltage. I have tried with other ISID too, virtual and native on DELL D630.
Reported values by ICOM A2 with engine off 11.3 , with engine on 12.8

I have tested other BMW diagnostics tool, it shows good voltage.
BMW reprogramming requires at least 13V, so I’m unable to do programming, I guess if I use other car for supply voltage to my car, will not be enough too.

bmw-icom-a2 bmw-icom-a2-software

obd2eshop technicians replied me that I need to get one additional voltage charger because when you use ICOM A2 to program BMW, it will use almost 3 hours or more, show low battery is inevitable, and I will need to get a stable power supply for it.