STORAGE BATTERY CHARGING DEVICE

In a battery charger of the kind in which pulsating d.c. is supplied to the battery (6) from the rectified output of transformer (1) until a threshold device 15 detects the battery is charged, a bimetallic strip (9, 10) responds to the charging current. If the battery draws high current, say upon initial charging, then resistor 9 heats up strip 10 causing it to break the circuit until the strip cools. The resistor and bimetal strip are chosen so as to allow an average current flow within the capabilities of transformer 1, thus obviating the need for a current limit resistor, and protecting the circuit. Once the battery has charged sufficiently, the bimetallic strip ceases to operate. The device is said to enhance reliability and to permit a smaller and lighter transformer to be used.