Module No. 3516
Battery
The special rechargeable battery used by your watch is not intended to be removed or replaced by you. Use of a rechargeable battery other than the special one specified for your watch can damage your watch.
The rechargeable (secondary) battery can be charged by using the charging cable to connect the watch to a device equipped with a USB terminal, so it does not require regular replacement as the primary battery requires. Note, however, that long use or operating conditions can cause the capacity or charging efficiency of the rechargeable battery to deteriorate. If you feel that the amount of operation provided by charging is too short, contact your original retailer or CASIO service center.
Regular, once-a-month charging is recommended to extend the service life of the watch’s battery.