| 摘要 |
<p>An overcharge preventing device and an overdischarge preventing device for a nonaqueous electrolyte secondary battery (14) is disclosed, in which voltage detectors (17, 18, 19) are provided to respectively detect terminal voltages of batteries (14A, 14B) connected in series, and a switch (16) is provided in series to the batteries (14A, 14B) between a common terminal (11) and a charge terminal (13). When the terminal voltage of at least one of the batteries (14A, 14B) exceeds a battery design voltage in charging the batteries, the switch (16) is turned off according to an output from the corresponding voltage detectors (17,18), thereby cutting off a charging current. Further, a voltage detector (19) is provided to detect a terminal voltage of the series connected batteries (14A, 14B), and a switch (15) is provided in series to the batteries between the common terminal (11) and a discharge terminal (12). When the terminal voltage of the batteries becomes equal to or less than a set voltage in discharging the batteries, the switch (15) is turned off according to an output from the voltage detector (19), thereby cutting off a discharging current. <IMAGE></p> |
