Patent ID: 11881566
Assignee: DENSO CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC G  H

Claim 0:
1. A battery pack monitoring system for monitoring a battery pack including multiple cell groups, each of which is formed of multiple battery cells connected in series in multiple stages, and an inter-group wiring connecting a high voltage side cell group and a low voltage side cell group in the multiple cell groups, the battery pack monitoring system comprising:
a first wiring connected to a positive electrode of each battery cell;
a second wiring connected to a negative electrode of each battery cell;
an RC filter formed of a resistor, which is provided at the positive side of the battery cell in the first wiring, and a capacitor, which is connected between the first wiring and the second wiring; and
a voltage monitoring device including a voltage detector connected between the first wiring and the second wiring for monitoring a voltage of each battery cell, wherein:
the voltage monitoring device includes therein a discharging switch connected between two second wirings connected to the negative electrodes of the battery cells connected in series and adjacent to each other;
the first wiring, the second wiring and the discharging switch are connected also to both ends of the inter-group wiring;
the second wiring connected to each battery cell is provided with a discharging resistor at a position where a charged electricity of the capacitor forming the RC filter is not discharged;
the second wiring connected to a lower potential side of the inter-group wiring is provided with a current limiting resistor, which has a resistance value higher than that of the discharging resistor;
a series circuit of a substitute discharging switch and a discharging resistor is provided between two second wirings connected to the positive electrode and the negative electrode of the battery cell which is connected to the inter-group wiring; and
the substitute discharging switch is turned on by a voltage drop generated when a current flows in the current limiting resistor.