Apparatus for monitoring the voltage of a battery pack having a plurality of battery cells connected in series

1. A battery voltage monitoring apparatus for monitoring a voltage of a battery pack having a plurality of battery cells connected in series, the battery voltage monitoring apparatus comprising:

a voltage sensor and a voltage sensor module having a first and a second input terminals connected to the voltage sensor;

a first terminal connected with the first input terminal and supplied with a voltage output from a highest battery cell located at a top of the plurality of battery cells connected in series;

a second terminal connected with the second input terminal and supplied with a voltage output from a battery cell located at a second top following the highest battery cell; and

a voltage clamp circuit for clamping a voltage between the first and the second terminals not to be over a specified value.

2. The battery voltage monitoring apparatus according to claim 1 , wherein the voltage clamp circuit is a voltage clamp device connected between the first and the second terminals.

3. The battery voltage monitoring apparatus according to claim 2 , wherein the voltage clamp device is a diode connected in forward direction from the second terminal to the first terminal.

4. The battery monitoring apparatus according to claim 1 , further comprising:

a first resistance with its one end connected to the first terminal;

a comparator for comparing a voltage of another end of the first resistance with a reference voltage generated according to a voltage of the first terminal;

wherein the battery voltage monitoring apparatus determines whether or not a disconnection of a line exists according to a result of the comparison.

5. The battery voltage monitoring apparatus according to claim 2 , further comprising:

a first resistance with its one end connected to the first terminal;

a comparator for comparing a voltage of another end of the first resistance with a reference voltage generated according to a voltage of the first terminal;

wherein the battery voltage monitoring apparatus determines whether or not a disconnection of a line exists according to a result of the comparison.

6. The battery voltage monitoring apparatus according to claim 4 , wherein the reference voltage is generated from a second resistance with its one end connected to the first terminal.

7. The battery voltage monitoring apparatus according to claim 4 , wherein the reference voltage is generated by the second resistance with its one end connected to the first terminal and a current source connected to the second resistance.

8. A battery voltage monitoring apparatus for monitoring a voltage of a battery pack having a plurality of battery cells connected in series, the battery voltage monitoring apparatus comprising:

a first terminal supplied with a highest voltage of the battery pack; and

a voltage clamp circuit for maintaining a voltage of the first terminal not to decrease below a specified voltage.

9. The battery voltage monitoring apparatus according to claim 8 , wherein the voltage clamp circuit is a voltage clamp device connected between the first terminal and a second terminal different from the first terminal.

10. The battery voltage monitoring apparatus according to claim 9 , wherein the voltage clamp device is a diode connected in forward direction from the second terminal to the first terminal.

11. The battery voltage monitoring apparatus according to claim 8 , further comprising:

a first resistance with its one end connected to the first terminal;

a comparator for comparing a voltage of another end of the first resistance with a reference voltage generated according to a voltage of the first terminal;

wherein the battery voltage monitoring apparatus determines whether or not a disconnection of a line exists according to a result of the comparison.

12. The battery voltage monitoring apparatus according to claim 11 , wherein the reference voltage is generated from a second resistance with its one end connected to the first terminal.

13. The battery voltage monitoring apparatus according to claim 11 , wherein the reference voltage is generated by the second resistance with its one end connected to the first terminal and a current source connected to the second resistance.