| US 7,586,290 B2 | ||
| Battery state of charge detection | ||
| Takeshi Hirata, Zama (Japan); Tsuyoshi Yamanaka, Yamato (Japan); and Yuji Nakada, Tokyo (Japan) | ||
| Assigned to Nissan Motor Co., Ltd., Yokohama-shi (Japan) | ||
| Filed on Jun. 10, 2005, as Appl. No. 11/149,587. | ||
| Claims priority of application No. 2004-174055 (JP), filed on Jun. 11, 2004. | ||
| Prior Publication US 2005/0280396 A1, Dec. 22, 2005 | ||
| Int. Cl. H02J 7/00 (2006.01) | ||
| U.S. Cl. 320—132 [180/65.3; 701/22] | 7 Claims |
| 1. A battery state of charge detection device for use with an electric circuit that drives a motor by using a current supplied
from a battery, the electric circuit comprising an inverter that controls operation of the motor and a controller that outputs
a motor control signal to the inverter to supply from the battery to the motor a current corresponding to a requested output
to the motor, the battery having a rated discharge range relating to a discharge current, the battery state of charge detection
device comprising:
a first current sensor that detects a discharge current of the battery, the first current sensor having a measurable current
range that slightly exceeds an upper limit value of the rated discharge range; and
a microprocessor programmed to:
determine whether or not the current detected by the first current sensor exceeds the upper limit value;
compute a state of charge of the battery based on the motor control signal when the current detected by the first current
sensor exceeds the upper limit value; and
compute the state of charge of the battery based on a current value detected by the first current sensor when the current
detected by the first current sensor does not exceed the upper limit value.
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