Self-contained rechargeable electrical-power cell

A self-contained rechargeable electrical-power cell comprising:

• a canister having at least one side wall with side-wall inner and outer surfaces longitudinally extending between longitudinally opposed upper and lower canister ends, the side wall and upper and lower ends defining an interior cell cavity;
• a rechargeable voltaic cell situated within the cell cavity and including a cell cathode and cell anode;
• a photovoltaic panel disposed along the outer surface of the canister side wall and including electrically-conductive first and second panel leads, the photovoltaic panel being configured for converting electromagnetic energy that impinges thereon into electrical current;
• electrical charging circuity situated in electrical communication with the photovoltaic panel through the first and second panel leads and the rechargeable voltaic cell through the cell cathode and cell anode, and configured such that, in a charging mode, electric current outputted by the photovoltaic panel is communicated to the rechargeable voltaic cell, where it is stored as electric charge;
• electrical-power cell positive and a negative terminals, each of which terminals is defined in one of the upper and lower canister ends;
• and
• electrical discharging circuitry situated in electrical communication with the rechargeable voltaic cell through the cell cathode and cell anode and the positive and negative terminals, and configured such that, when the electrical-power cell is incorporated within an external electrical circuit for the purpose of energizing that external electrical circuit, electric charge stored within the rechargeable voltaic cell can be selectively discharged into the external circuit through the electrical discharging circuitry.