Battery protection system and process for charging a battery

摘要

A battery protection system (20) controls a process for charging a battery pack (15). A hysteresis comparator (54) senses a charging current flowing through the battery pack (15) and switches off a charging switch (31) to interrupt the charging current when the charging current reaches an upper limit. A transient current is then generated by an inductor (34). The hysteresis comparator (54) senses the transient current flowing through the battery pack (15) and switches on the charging switch (31) to regenerate the charging current when the transient current decreases substantially to zero. Periodically, a battery monitoring circuit (40) switches off the charging switch (31) and measures an open circuit voltage across each battery cell in the battery pack (15). In response to the open circuit voltage of a battery cell reaching a fully charged voltage, the battery monitoring circuit (40) switches off the charging switch (31) to terminate the charging process.