Series-connected battery packs, system and method

Patent metadata

Field	Value
Publication number	US-10483791-B2
Application number	US-201715603862-A
Country	US
Kind code	B2
Filing date	May 24, 2017
Priority date	May 25, 2016
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A power device, system and method. The device may include a housing defining a first support operable to support a first battery pack, and a second support operable to support a second battery pack; a circuit selectively electrically connecting the first battery pack and the second battery pack in series, the circuit including an output terminal to provide an output voltage to a powered device, a first bypass portion operable to selectively electrically disconnect the first battery pack from the circuit, and a second bypass portion operable to selectively electrically disconnect the second battery pack from the circuit; and a boost converter electrically connected to the circuit and operable to boost a voltage at the output terminal.

First claim

What is claimed is:

1. A power device comprising:
a housing defining a first support operable to support a first battery pack including a first plurality of battery cells, and a second support operable to support a second battery pack including a second plurality of battery cells;
a circuit selectively electrically connecting the first battery pack and the second battery pack in series, the circuit including
an output terminal to provide an output voltage,
a first bypass portion operable to selectively electrically disconnect the first battery pack from the circuit, and
a second bypass portion operable to selectively electrically disconnect the second battery pack from the circuit;

a motor receiving the output voltage from the output terminal; and
a boost converter electrically connected to the circuit and operable to boost the output voltage at the output terminal, wherein boost converter is controlled to boost the output voltage based on a characteristic of the motor.

2. The device of claim 1 , wherein the boost converter is selectively electrically connected in series with the first battery pack and the second battery pack, the boost converter being operable to boost a first voltage of the first battery pack and a second voltage of the second battery pack to the output voltage.

3. The device of claim 1 , wherein the device is configured to operate with a first battery pack having one of a first nominal voltage, a first capacity, and a first state of charge and with a second battery pack having a corresponding one of a second nominal voltage, a second capacity, and a second state of charge different than the first.

4. The device of claim 1 , wherein the first support is operable to removably support the first battery pack and the second support is operable to removably support the second battery pack.

5. The device of claim 1 , further comprising a controller operable to
determine characteristics or condition of the first battery pack, and
control operation of the first bypass portion.

6. The device of claim 5 , wherein, when the first battery pack is to be disabled, the controller controls the first bypass portion to disconnect the first battery pack from the circuit.

7. The device of claim 6 , wherein, when another battery pack is substituted for a disabled first battery pack, the controller is operable to determine whether to control the first bypass portion to connect the other battery pack to the circuit.

8. The device of claim 1 , further comprising a controller operable to
determine an input voltage of the motor, and
control the boost converter to the voltage at the output terminal to the input voltage.

9. A power system comprising:
a first battery pack including a first plurality of battery cells;
a second battery pack including a second plurality of battery cells; and
a battery power device operable to provide an output voltage to a motor, the battery power device including
a housing defining a first support operable to support the first battery pack, and a second support operable to support the second battery pack,
a circuit selectively electrically connecting the first battery pack and the second battery pack in series, the circuit including
an output terminal to provide the output voltage to the motor,
a first bypass portion operable to selectively electrically disconnect the first battery pack from the circuit, and
a second bypass portion operable to selectively electrically disconnect the second battery pack from the circuit, and

a boost converter electrically connected to the circuit and operable to boost a voltage at the output terminal, wherein boost converter is controlled to boost the voltage based on a characteristic of the motor.

10. The system of claim 9 , wherein the boost converter is selectively electrically connected in series with the first battery pack and the second battery pack, the boost converter being operable to boost a first voltage of the first battery pack and a second voltage of the second battery pack to the output voltage.

11. The system of claim 9 , wherein the first battery pack has a first nominal voltage and the second battery pack has a second nominal voltage different than the first nominal voltage.

12. The system of claim 9 , wherein the first battery pack has a first capacity and the second battery pack has a second capacity different than the first capacity.

13. The system of claim 9 , wherein the first battery pack has a first state of charge and the second battery pack has a second state of charge different than the first state of charge.

14. The system of claim 9 , wherein the first battery pack includes
a battery pack housing removably supported by the first support,
a battery cell supported by the battery pack housing, and
a terminal operable to connect the battery cell to the circuit.

15. The system of claim 14 , wherein the second battery pack includes
a second battery pack housing removably supported by the second support,
a second battery cell supported by the battery pack housing, and
a second terminal operable to connect the battery cell to the circuit.

16. The system of claim 9 , further comprising a controller operable to
determine characteristics or condition of the first battery pack, and
control operation of the first bypass portion.

17. The system of claim 16 , wherein, when the first battery pack is to be disabled, the controller controls the first bypass portion to disconnect the first battery pack from the circuit.

18. The system of claim 17 , wherein, when another battery pack is substituted for a disabled first battery pack, the controller is operable to determine whether to control the first bypass portion to connect the other battery pack to the circuit.

19. The system of claim 9 , further comprising a controller operable to
determine an input voltage of the motor, and
control the boost converter to the voltage at the output terminal to the input voltage.

20. A method of powering a motor, the method comprising:
selectively electrically connecting a first battery pack and a second battery pack in a circuit in series, wherein the first battery pack includes a first plurality of battery cells and the second battery pack includes a second plurality of battery cells;
providing an output voltage at an output terminal;
boosting a voltage at the output terminal;
receiving, at the motor, the output voltage from the output terminal; and
when one of the first battery pack and the second battery pack reaches an end of discharge condition, selectively electrically disconnecting the one of the first battery pack and the second battery pack from the circuit
wherein the voltage at the output terminal is boosted based on a characteristic of the motor.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Mergener Matthew J
• Obermann Timothy Ryan
• Glasgow Kevin L
• Brozek Jeffrey M

Classifications

• H02J7/61

  against overcharge · CPC title

• H02J7/855

  with circuits adapted for supplying loads from the battery · CPC title

• H02J7/825

  Detection of fully charged condition · CPC title

• H02J7/575

  Parallel/serial switching of connection of batteries to charge or load circuit · CPC title

• H02J7/54

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title