Digital fuel display

[adrianloker]

Upon filling with fuel, the fuel gauge registered the input, but the digital range display didn't increase, I have since travelled many more miles than the indicated miles available. Digital display went to zero. The latest fuel fill has returned digital display to a positive reading but not to what the expected level should be.
Will disconnecting the battery reset the display or is there a known issue with the display?
My car is 2002 2ltr petrol automatic with 60,000 miles.