A terminal device including a solar battery panel; a panel temperature-detection unit configured to detect a temperature measured near the solar battery panel; a power generation-state determination unit configured to detect an illuminance measured near the solar battery panel; a battery temperature-detection unit configured to detect a temperature measured near a secondary battery charged through power generated through the solar battery panel; a control unit configured to estimate a change in the temperature detected through the battery temperature-detection unit based on the temperature detected through the panel temperature-detection unit and the illuminance obtained through the power generation-state determination unit, and determine a remaining time when the estimated temperature measured near the secondary battery reaches a temperature at which the charging of the secondary battery is stopped; and a notification unit configured to provide notification about the remaining time determined through the control unit.