Casio Waveceptor watches are self-setting, radio-controlled timepieces that use a small solar panel and rechargeable battery to make frequent battery changes a thing of the past. Though rechargeable batteries last much longer than traditional watch batteries, rechargeables can sometimes lose their ability to hold a charge over time. Casio recommends that wearers send watches with battery problems to authorized service centers, but daring do-it-yourselfers can change the battery in their Waveceptor at home in just minutes. Home repairs, however, may void the warranty.

Choose and prepare a workspace before beginning the battery-replacement process. Look for a clean, flat surface in a quiet and well-lit room. Move a bright floor or desk lamp near your workspace, if necessary, to improve lighting conditions. Put down a soft cloth, pot holder or neoprene mouse pad to prevent the watch's glass face from rubbing against the work surface.

Place your Casio Waveceptor face-down on the padded work surface. Note the location of the four small screws that hold the back cover to the rest of the watch casing. Remove the four screws with a Phillips screwdriver sized for optical use; retain the screws for reassembly. Remove the watch's back cover carefully to avoid damaging the rubber waterproofing gasket; set aside.

Lift the protective white plastic plate out of the watch case with a pair of needle-nose metal tweezers to reveal the battery compartment; the battery is held in the compartment with a metal latch. Use the tweezers or an optical-size flat-blade screwdriver to raise the latch, so you can access the battery.

Exchange the spent battery with an identical rechargeable battery; pry the old battery free with the tweezers or flat-blade screwdriver if it proves stubborn to remove. Observe the indicated polarity when inserting the new battery into the Waveceptor's battery compartment. Short the newly installed rechargeable battery by touching the tips of the metal tweezers to the battery and AC terminal for two seconds. Lower the metal strap to hold the battery in place.

Place the protective white plastic plate over the battery compartment and replace the back cover. Reinsert the four retained screws and tighten them with the small Phillips screwdriver.