I had a Willier Cento 1 Hybrid for a year. In May 2021 the LED started flashing violet/pink when trying to use the Range Ext. Battery. Problem solved with update of the REB. I noticed two new issues. 1) When the REB goes to zero the led starts flashing pink/violet, thou the motor keeps working. To restore normal conditions I have to turn the main battery off and on again. 2) Cannot charge 2 batteries simultaneously.