Replace all four batteries when you notice a marked decrease in the range or response of your remote control, or when you see the low battery indicator (Lifestyle® V25, V35, 235 and 135 systems) on the display.
Slide the battery compartment cover off the back of the remote control
Remove the old batteries
Install four new AA (IEC-LR6) 1.5V batteries, matching the polarity markings (+ and –) to the markings inside the battery compartment
Slide the battery cover back into place