Lenovo A3000 Tablet - Manual (Page 5)

You can charge your IdeaTab whether it is on or off.
When the battery level falls below the threshold, IdeaTab will alert you with
a tone and the battery status icon will change into . We recommend you
plug the AC power adapter into your IdeaTab in the direction of the orange
arrow as shown above figure.
If your IdeaTab is being charged while it is on, the battery status icon
(located on the status bar of the screen) will appear as . After the battery
has finished charging, the status bar will show the fully charged icon .
For more information on battery safety, see the Important Product
Information Guide .
Charging IdeaTab