United States Patent im
Hutchings
[li] Patent Number: 4,843,299 [45] Date of Patent: Jun. 27, 1989
[54] UNIVERSAL BATTERY CHARGING SYSTEM AND A METHOD
[75] Inventor: Phillip D. Hutchings, Calne, United Kingdom
[73] Assignee: Power-Tech Systems Corporation, Kent, Conn.
[21] Appl. No.: 55,795
[22] Filed: Jun. 1,1987
[51] Int. Q.4 H02J7/04
[52] U.S. a 320/31; 320/32;
320/39
[58] Field of Search 320/15, 20-24,
320/39, 40, 14, 37, 31, 32; 323/319
[56] References Cited
U.S. PATENT DOCUMENTS
3,517,294 6/1970 Ruben 320/24
3,688,177 8/1972 Reeves 320/24
4,270,080 5/1981 Kostecki 320/24
4,392,101 7/1983 Saar et al 320/39 X
4,507,531 3/1985 Teich et al 323/319 X
4,639,655 1/1987 Westhaver et al 320/14
4,647,834 3/1987 Castleman 320/37 X
4,670,703 6/1987 Williams 320/22
4,710,694 12/1987 Sutphin et al 320/24
OTHER PUBLICATIONS
Graf, Ed., "Radio Shack Dictionary of Electronics", 1978-1979 ed., p. 445.
Primary Examiner—R. J. Hickey
Attorney, Agent, or Firm—L. Lawton Rogers, HI;
Joseph M. Killeen
[57] ABSTRACT
A universal battery charger and recharger for electric batteries having different charging characteristics. The battery charger includes a microprocessor receiving inputs from current, voltage and temperature sensors for controlling the battery charging profile. A replaceable memory may be included to provide an appropriate charging profile for the battery to be charged. The supply current is varied responsively to the voltage across the battery which is measured when the supply current reaches a predetermined level or after a predetermined time.
4 Claims, 6 Drawing Sheets
