Secondary battery protection apparatus

Patent metadata

Field	Value
Publication number	US-11101672-B2
Application number	US-202017016469-A
Country	US
Kind code	B2
Filing date	Sep 10, 2020
Priority date	Apr 24, 2015
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A secondary battery protection apparatus includes a plurality of secondary battery protection apparatuses. One of two adjacent secondary battery protection apparatuses includes a voltage determination unit that is not affected by a current transfer signal and configured to receive, through a single communication line, the current transfer signal that is transmitted from the other of the two adjacent battery protection apparatuses through the single communication line and an information element based on changes of a voltage value of a voltage transfer signal, and a current determination unit that is not affected by the voltage transfer signal and configured to receive, through the single communication line, the voltage transfer signal that is transmitted from the other of the two adjacent secondary battery protection apparatuses through the single communication line and an information element based on changes of the current value of the current transfer signal.

First claim

What is claimed is:

1. A secondary battery protection apparatus including a plurality of secondary battery protection apparatuses that form a secondary battery protection system, each of the plurality of secondary battery protection apparatuses being connected in parallel with a plurality of secondary battery cells connected in series, wherein signal transmissions are performed between the plurality of the secondary battery protection apparatuses, said plurality of secondary battery protection apparatuses being connected to each other in cascade via a single communication line, wherein the secondary battery protection apparatus comprises:
a current transmission unit configured to generate and transmit a current transfer signal to the single communication line upon a first condition being met, a current value of the current transfer signal being changed according to the first condition without changing a voltage;
a voltage determination unit configured to determine a voltage value of a voltage transfer signal based on a threshold value;
a voltage transmission unit configured to generate and transmit the voltage transfer signal to the single communication line upon a second condition being met, the voltage value of the voltage transfer signal being changed according to the second condition without changing a current; and
a current determination unit configured to determine the current value of the current transfer signal based on a threshold value;
wherein the current transfer signal and the voltage transfer signal are transmitted at a same time via the single communication line that is shared by two adjacent secondary battery protection apparatuses among the plurality of secondary battery protection apparatuses when each of the two adjacent secondary battery protection apparatuses is transmitting the voltage transfer signal and the current transfer signal to each other,
wherein a voltage amplitude of the voltage transfer signal transmitted from each of the two adjacent secondary battery protection apparatuses is equal to or less than a predetermined voltage, the predetermined voltage being less than voltages of secondary battery cells connected to the two adjacent secondary battery protection apparatuses relative to a connecting point of the secondary battery cells and less than withstand voltages of the two adjacent secondary battery protection apparatuses,
wherein one of the two adjacent secondary battery protection apparatuses comprises:
said voltage determination unit, that is configured not to be affected by the current transfer signal, and configured to receive, through the single communication line, the current transfer signal that is transmitted from the other of the two adjacent secondary battery protection apparatuses that is connected in the series through the single communication line and an information element based on changes of the voltage value of the voltage transfer signal, and
said current determination unit, that is configured not to be affected by the voltage transfer signal, and configured to receive, through the single communication line, the voltage transfer signal that is transmitted from the other of the two adjacent secondary battery protection apparatuses that is connected in the series through the single communication line and an information element based on changes of the current value of the current transfer signal, and
wherein each of the two adjacent secondary battery protection apparatuses has a transmission/reception terminal that is directly connected to each other.

2. The secondary battery protection apparatus according to claim 1 , wherein the one of the two adjacent secondary battery protection apparatuses is powered by the secondary battery cells that are connected in parallel.

3. The secondary battery protection apparatus according to claim 1 , wherein the current transmission unit includes one or more constant current supplies, and the current transfer signal is generated by turning on/off the constant current supplies.

4. The secondary battery protection apparatus according to claim 1 , wherein the voltage transmission unit includes one or more constant voltage circuits, and the voltage transfer signal is generated by controlling the constant voltage circuits.

5. The secondary battery protection apparatus according to claim 4 , wherein each of the constant voltage circuits includes one or more diodes, and a constant voltage is generated based on the forward voltage of the one or more diodes.

6. The secondary battery protection apparatus according to claim 1 , further comprising a control unit configured to output a control signal for switching between a charge operation and a discharge operation of a secondary battery cell that is connected in parallel based on one of determination results of the current determination unit and the voltage determination unit, and the control unit being further configured to perform recovery from a charge protection state or a discharge protection state of the secondary battery cell that is connected in parallel to a normal state based on the other of the determination results of the current determination unit and the voltage determination unit.

7. The battery protection apparatus according to claim 6 , wherein the transmission/reception terminal is used for outputting the control signal and also used for transmitting the current transfer signal transmitted from one of the two adjacent secondary battery protection apparatuses and receiving the voltage transfer signal transmitted from the other of the two adjacent secondary battery protection apparatuses.

8. The secondary battery protection apparatus according to claim 7 , further comprising a switch configured to cause the transmission/reception terminal to switch between a first state and a second state of the transmission/reception terminal, wherein the transmission/reception terminal outputs the control signal in the first state while the transmission/reception terminal transmits the current transfer signal transmitted from one of the two adjacent secondary battery protection apparatuses and receives the voltage transfer signal transmitted from the other of the two adjacent secondary battery protection apparatuses in the second state.

9. The secondary battery protection apparatus according to claim 1 , wherein the first condition is met upon one of abnormalities of overcharge, over discharge and overcurrent with respect to the secondary battery cells being detected.

10. The secondary battery protection apparatus according to claim 1 , wherein the second condition is met upon any of connection of a load to the secondary battery cells, disconnection of the load and disconnection of a battery charger being detected.

Assignees

• Shibata Kohei
• Mitsumi Electric Co Ltd

Inventors

• Shibata Kohei

Classifications

• H02J7/685

  using connection detecting circuits (H02J7/68 takes precedence) · CPC title

• H02J7/63

  against overdischarge · CPC title

• H02J7/62

  against overcurrent · CPC title

• H02J7/61

  against overcharge · CPC title

• H02J7/50 Primary

  acting upon multiple batteries simultaneously or sequentially · CPC title