Volvo 2008 V70 Owner's Manual page 45

Replacing the battery in the remote key
The batteries should be replaced if:
The information symbol illuminates and
if the locks do not react after several attempts to unlock or lock the vehicle.
NOTE
The remote key's range is normally approximately 60 ft (20 m) from the vehicle.
See page 60 for information on replacing the battery.
Common functions - Remote key/Personal Car Communicator (PCC)
Lock
Unlock
Approach lighting
Tailgate unlock
Panic alarm
Buttons on the remote
Lock - Press the Lock button on the remote once to lock all doors and the tailgate. The turn signals will flash once to
confirm locking.
Unlock - Press the Unlock button on the remote once to unlock the driver's door. The turn signals will flash twice to
confirm unlocking.
After a short pause, press the Unlock button a second time within 10 seconds to unlock the other doors and the tailgate.
This function can be changed so that all doors unlock at the same time under
Replace car key battery is shown in the display and/or
Car settings lock settings Doors,