Patent ID: 7327544

Claim:
A battery protection structure, comprising: a low voltage drop element coupled to a battery voltage source; a charging limiting element controlled by a plurality of control signals and being coupled to the low voltage drop element and an output voltage to be supplied to a load; wherein during a normal operating mode during which the battery voltage source is not supplying power to the load and a primary voltage source is supplying power to the load, the battery charging limiting element and the voltage drop restricting element operate to prevent charging of the battery beyond a predetermined threshold; and wherein during a backup operating mode the battery voltage source supplies power to the load, and during which the primary voltage source does not supply power to the load, the low voltage drop restricting element may be chosen to reduce voltage drop between the battery voltage source and the load and wherein a voltage drop in the path of the battery during the backup operating mode is set by selecting a resistance value in the low voltage drop element.