Yes Erel.... the supply never change but the battery indicator shows the discharge. I think thath android calculates the remaining battery duration when the tablet start and not sample the current remaining in the battery. When I turn on the tablet the battery level indicator shows 100% and here start to show the discharge. You are shure that with an USB otg Cable and a powered USB/HUB I can supply the tablet and make work the USB to Serial converter? Thank's