GB693750A - Improvements in and relating to methods of and apparatus for charging electric storage batteries - Google Patents

Abstract

693,750. Battery-charging systems. BRITISH THOMSON-HOUSTON CO., Ltd. Feb. 7, 1950 [Feb. 23, 1949], No. 3142/50. Class 38 (iv). Storage batteries 3, 4 are separately and sequentially given a partial charge at a high rate and are then connected in parallel and receive a final charge at a reduced rate. Closure of a main switch 7 energizes a charging rectifier 2 over transformer 6 and causes relays 14, 21 to pick up. The first relay shorts out a resistor 12 at contacts 13 and opens its contacts 22 to remove a by-pass around contacts 26 of relay 21 which, in picking up, causes (a) energization of contactor 15 (over contacts 26) to connect battery 3 to the rectifier and (b) de-energization of contactor 18 (at contacts 25) to disconnect battery 4 from the rectifier. Upon battery 3 attaining a predetermined voltage-say corresponding to 80 per cent full charge-relay 27 responds and, at its contacts 30, de-energizes relay 21. The conditions of contactors 15, 18 reverse, in consequence, so that battery 4 is put on charge and battery 3 disconnected. Relay 28 responds when battery 4 reaches a given voltage and thus causes relay 14 to drop out. Closure of its contacts 22 re-energizes contactor 15 and the batteries are now charged in parallel at a reduced rate determined by the resistor 12, which is now effective, charging continuing until the A.C. supply is interrupted by a time switch 8 which was set in operation by the drop out of relay 14.