Hello Luca,
I have good news for you!
My friend had the same problem (B6 error) with his Brammo Enertia+ as you and managed to solve it.
Here is the procedure:
1) Disconnect two cables on the front of the charger
2) Disconnect one cable on the front of the control unit
3) Press the reset button
4) Connect all three cables
I hope this helps you too, let me know how it came about.