I have an Acer Aspire V5 ultrabook, owned for just over a year now and it does the same thing as well. Even though the battery is fully charged. When I turn it back on it says charged or shows the last battery % like 60%. It usually can run without the charger being plugged in and go for 5 hours or more based on what I'm using it for. I don't know what to do. It just started happening recently.