The E06 code just means that the battery is empty.
You can cycle through the settings by just pressing the power button once turned on.
You will see the letter V (looks more like a U) where the mileage is usually displayed. This is the voltage.
Also, ensure that P03 and P15 is correctly set.
Another possibility is that the charger is defective. Do you have a voltmeter at home? If you do, please measure the charger output - it should show 54.6V.