Dell Inspiron 13z (N311z, Mid 2011) - Manual (Page 11)

Before You Begin 11
CAUTION: To help prevent damage to the system board, remove the main battery
(see "Removing the Battery" on page 13) before working inside the computer.
7 Remove the battery. See "Removing the Battery" on page 13.
8 Turn the computer top-side up, open the computer, and press the power
button to ground the system board.