Abstract: A battery charger, particularly suitable for use with aircraft, receives power from a variable source of direct current power. The received power voltage is boosted to a level no lower than a preselected level above battery voltage and regulated so that a constant charging current is supplied to a battery under charge in each of several charging modes. The charger has controls which are responsive to various battery parameters and circuitry to initiate various safety signals. The constant charging current is supplied by a buck regulator which has MOSFET transistors connected to form a current regulating loop.

Abstract: A battery charger receives electrical power from an external source of direct current electrical power. The power is received through a first inductor which supplies it to a second node. First switching means receives the power from the second node and supplies it to a third node. A second inductor receives the power from the third node and supplies it to the battery to be charged through output connector means. Second switching means are connected to the second node and to a capacitor which is connected to the third node so that the second switching means can switch the capacitor between series circuit and parallel circuit configurations with respect to the first and second inductors. A safety circuit is connected to temperature sensing means positioned to sense the temperature of the battery to be charged, to the first node and to the first switching means. The safety circuit causes the first switching means to become nonconductive upon detection of unsafe conditions which may occur when charging.

Abstract: A pulsed current battery charging method functions to improve battery capacity characteristics of a liquid electrolyte electrical storage battery and prolong battery useful life. Pulses of charging current are applied optionally concurrent with conventional charging current. The pulse amplitude is of significant magnitude in relation to conventional small, finishing rate or trickle charge charging currents. Pulse amplitude, duration and pulse repetition rate are controllable. Apparatus designed to carry out this method includes power supply means, pulse current generating means and optional control means.