Charging system for battery powered devices

• Main Author: STEWART; GREGORY N
• Format: Patent
• Language: English
• Published: 04.06.1996
• Edition: 6
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

A system for controlling the rate and duration of battery charging. A microprocessor is connected in a battery current signal feedback loop and used to control the battery charge cycle. The rate of charge is gradually stepped up at the beginning of the charge cycle until the charging current reaches a defined maximum value, and thereafter maintained between the maximum and a defined minimum value for the duration of the charge cycle. The microcontroller terminates the charge cycle when the battery charging current begins to increase while the rate of charge remains constant, this being an indication that the battery is fully charged. Sensors input signals to the microcontroller to prevent or terminate charging if the battery cells are not within an appropriate temperature range, or if a short circuit or other adverse condition arises.