| 摘要 |
A charger for recharging the batteries of a portable electronic device even when no external power source is available. A battery or cell is installed within the charger, and when no access is available to a fixed power source into which the charger can be plugged, the internal battery or cell can be used to recharge the electronic device. The internal battery can be a primary battery or a secondary battery. In the latter case, the internal battery can be maintained in a charged state by means of circuitry which, when the charger is plugged into the external power source, charges the internal battery as well as the battery of the electronic device. The external power source can be either an AC power wall socket, in which case the charger includes AC/DC voltage conversion circuits, or a car lighter socket, or the DC output of a conventional wall charger. |
