You should be able to achieve sufficient charging by ensuring that it is exposed to indoor and outdoor lighting as much as possible throughout the day. Note, however, that charging under very hot conditions, like the ones described below, can lead to malfunction or burn injury.
o On the dash board of a car parked in the sun
o Close to an incandescent light or some other source of intense heat
o Any area exposed for long periods to direct sunlight
Also note that charging efficiency is degraded if any part of the solar cell is blocked.

Water-resistant models need to have their rubber seals replaced every two or three years in order to ensure proper water resistance.

Use the light, alarm, and other power-hungry features, only when you really need them. If your watch has a Full Auto Light feature, turn the feature off when you do not need to illuminate the face of the watch.

If you are going to leave the watch in a drawer or somewhere else where it will not be exposed to light, first charge it completely and turn on its power saving feature to ensure that battery power is conserved.