Battery assembly controller which monitors voltages of secondary batteries and semiconductor integrated circuit used for the battery assembly controller

1. A battery assembly controller controlling a plurality of series-connected secondary batteries, the controller comprising:

a discharge circuit reducing terminal voltages of the plurality of secondary batteries; and

a monitoring circuit configured to monitor the terminal voltages of the secondary batteries, wherein

the discharge circuit includes a plurality of switches, each being connected to an associated one of the secondary batteries,

the battery assembly controller further includes:

a plurality of cell balancing terminals connecting the plurality of secondary batteries and the plurality of switches together; and

a plurality of voltage detection terminals connecting the plurality of secondary batteries and the monitoring circuit together, and

the plurality of cell balancing terminals and the plurality of voltage detection terminals are different terminals from each other.

2. The battery assembly controller of claim 1 , wherein the monitoring circuit includes a filtering capacitor switchably connected to the secondary batteries.

3. The battery assembly controller of claim 1 , wherein the monitoring circuit includes a filtering capacitor and a resistor switchably connected to the secondary batteries.

4. The battery assembly controller of claim 1 , wherein each of the switches includes a plurality of sub-switches connected in series.

5. The battery assembly controller of claim 1 , wherein each of the switches includes a sub-switch and a resistor, which are connected in series.

6. The battery assembly controller of claim 1 , further comprising

a control circuit controlling not to turn on odd-numbered and even-numbered switches simultaneously, where the switches are sequentially numbered as 1, 2, 3, . . . , from a high-potential side, wherein

the control circuit controls not to turn on adjacent ones of the switches simultaneously.

7. The battery assembly controller of claim 1 , wherein

one of the switches with highest potential is a p-channel MOS transistor, and

one of the switches with lowest potential is an n-channel MOS transistor.

8. The battery assembly controller of claim 1 , wherein

each of the switches is a MOS transistor, and

the discharge circuit further includes

a plurality of resistors, each being connected between a gate and a source of one of the MOS transistors,

a plurality of current supplies, and

a plurality of other switches, each being connected between the gate of one of the MOS transistors and associated one of the current supplies.

9. The battery assembly controller of claim 7 , wherein the discharge circuit further includes a plurality of short-circuit switches, each being connected between a gate and a source of one of the MOS transistors.

10. The battery assembly controller of claim 1 , wherein the discharge circuit further includes a plurality of resistors, each being connected in parallel to associated one of the switches.

11. The battery assembly controller of claim 9 , wherein the discharge circuit further includes a plurality of Zener diodes, each being connected in series to associated one of the resistors.

12. A semiconductor integrated circuit used for a battery assembly controller controlling a plurality of series-connected secondary batteries, the semiconductor integrated circuit comprising:

a discharge circuit reducing terminal voltages of the plurality of secondary batteries and including a plurality of switches, each being connected to an associated one of the secondary batteries;

a monitoring circuit monitoring the terminal voltages of the secondary batteries;

a plurality of cell balancing terminals connecting the plurality of secondary batteries and the plurality of switches together; and

a plurality of voltage detection terminals connecting the plurality of secondary batteries and the monitoring circuit together,

wherein the plurality of cell balancing terminals and the plurality of voltage detection terminals are different terminals from each other.