Please help! My tablet's battery is dying fast! Lenovo Ideapad A1

I assume the "No Service" displayed is one of those things left from the android phone functions which wasn't cleaned up. Whatever the reason it is there, there is no cell phone tranceiver in the tablet. Does the tablet use more than 50% of the battery after 4 hours of use? My tablet will run the battery down to 50% in 4 hours of use with the screen brightness at medium, WiFi on and Bluetooth and GPS off. If i use it for several hours a day I charge it up nightly as I don't like to run the battery below 50% to maximize it's life.

 

I had the SAME problem when I got my tablet too. I didn't use the cell service, but it was constantly draining the battery. Naturally I was frustrated. So I googled my problem and found that I had to turn on AIRPLANE MODE, and then turn my WIFI on again. It WORKED!!! Try that. When your tablet is on, hold the button down, and it will give you several options, one of which is "Airplane Mode ON/OFF." Turn it off, then go into your wifi settings and turn WIFI back on. (Enabling Airplane Mode automatically turns wifi off.)