Acer A1-830 - Manual (Page 7)

Using your tablet - 7
U
SING YOUR TABLET
Charging your tablet
For first-time use, you need to charge your tablet for four hours. After
that you can recharge the battery as needed.
Assembling the power adapter
Slide the large end of the USB cable into the power adapter body (it
will fit in only one direction).
Note
Charger illustration is for reference only. Actual configuration may vary.