When the batteries are almost empty, the charging light starts to flash red. When the charging light starts to flash red, the batteries still contain enough energy for a few minutes of operation. When the batteries are completely empty, the charging light lights up red continuously and the appliance stops working. To charge the epilator, connect it to the household power. You can also run the appliance directly from the household power by inserting the appliance plug into the jack of the appliance and the adapter into a wall outlet.