MAXIMUM CHARGE RATE ALGORITHM FOR PORTABLE BATTERIES
Original Publication Date: 1999-Sep-01
Included in the Prior Art Database: 2002-Aug-22
Presently rapid chargers charge batteries at a 1C rate while Ultra fast chargers charge at a fixed rate such as 3C or 4C. Portable batteries have special requirements that do not allow for the Ultra fast charging. This is true because: l- the radio has a maximum input voltage after which the radio trans- mit and receive amplifiers can be damaged, and 2- me portable battery has a reverse discharge protec- tion diode which has a maximum current limit asso- ciated to it. Hence a unique algorithm is needed that allows the battery to be charged in the shortest amount of time while still protecting the radio and battery. This is accomplished by determining the maximum allowable current for the battery based on the diode and by monitoring the battery voltage to assure that the radio maximum input voltage is not exceeded. This invention takes advantage of the existing capabilities of the charger to monitor bat- tery voltage and apply different charge currents and as such requires no new hardware.