Abstract: In an embodiment, an auxiliary-power-supply unit includes a connector and a controller configured to power a microgrid from a battery in response to determining that the connector is plugged into an outlet of the microgrid, and that the microgrid is uncoupled from a power grid. For example, the connector plugs into a wall outlet of a microgrid in, e.g., a home, and provides, from the battery during a power outage, auxiliary power to the microgrid and, therefore, provides auxiliary power to one or more devices, such as appliances, lights, computers, or televisions, that are connected to the microgrid.

Abstract: An electronic device, such as a radiotelephone, is connectable to a variable-level power source. The electronic device includes a rechargeable power source which is repowered responsive to application of operative power generated by the variable-level power source. The electronic device provides a constant charge current regulator for converting operative power of a constant voltage into operative power of a constant current to be applied to the rechargeable power source to recharge the rechargeable power source. The constant charge current regulator is made up of a series connected diode and resistor pair. According to a further aspect of the invention, when the rechargeable power source becomes fully recharged, application of the operative power can be reduced.