Single wire battery pack temperature and identification method

Patent metadata

Field	Value
Publication number	US-2017358830-A1
Application number	US-201715633638-A
Country	US
Kind code	A1
Filing date	Jun 26, 2017
Priority date	Dec 30, 2010
Publication date	Dec 14, 2017
Grant date	—

Abstract

Disclosed are techniques for identifying battery pack types and by inference battery chemistries by measuring a transient response of the battery pack to signal applied to the battery pack.

First claim

What is claimed is:

1 . A method for identifying a type of battery pack comprising:
receiving, by a controller device, an interrupt signal triggered upon: (i) insertion of the battery pack into a charging device or (ii) controller device startup when the battery pack is already installed in a charging device; in response to receiving the interrupt signal, measuring, by the controller device, a transient response of the battery pack; and determining, from the measured transient response, the battery pack type.

2 . The method of claim 1 , further comprising
determining a charging current to be applied to the battery pack based on the measured transient response; and applying the determined charging current to the battery pack.

3 . The method of claim 1 , further comprising:
applying, by the controller device, a signal to the sense terminal of the battery pack by setting a first terminal of a controller unit of a battery charger to a low state; measuring, by the controller device, a transient response of the battery pack to the applied signal; and measuring the transient response of the battery to the applied signal at a second, different terminal of the controller unit of the battery charger.

4 . The method of claim 3 , wherein further comprising:
computing a value of the transient response over the first and subsequent instances of time.

5 . The method of claim 1 , wherein determining the battery pack comprises:
accessing, by the controller device, a lookup table storing transient response values, associated with different types of battery packs to provide an indication of battery pack type.

6 . The method of claim 1 , wherein the battery is lithium-iron-phosphate electrochemical cell.

7 . The method of claim 1 , further comprising:
accessing, by the controller device, a lookup table storing transient response values, associated with plural, different types of battery packs to provide an identification of battery pack type; accessing, by the controller device, a second lookup table storing multiple charging current values, associated with the identified battery type; periodically measuring the voltage between terminals of the battery; and adjusting the charging current applied to the battery when the measured voltage between the terminals of the battery reaches a pre-determined voltage value such that the voltage between the terminals of the battery is maintained at the pre-determined voltage value.

8 . The method of claim 1 wherein the battery pack comprises a resistor and the transient response of the battery pack is measured taking into consideration the value of resistance of the resistor.

9 . A method for identifying a temperature of a battery pack comprising:
receiving, by a controller device, an interrupt signal triggered upon: (i) insertion of the battery pack into a charging device or (ii) controller device startup when the battery pack is already installed in a charging device; in response to receiving the interrupt signal, measuring, by the controller device, a voltage on a sense terminal of the battery pack that has a thermistor coupled to the sense terminal; determining, by the controller device, the temperature of the battery pack based on the measured voltage.

10 . The method of claim 9 , further comprising
determining a charging current to be applied to the battery pack based on the measured transient response; and applying the determined charging current to the battery pack.

11 . The method of claim 9 , further comprising:
applying, by the controller device, a signal to the sense terminal of the battery pack by setting a first terminal of a controller unit of a battery charger to a low state; measuring, by the controller device, a transient response of the battery pack to the applied signal; and measuring the transient response of the battery to the applied signal at a second, different terminal of the controller unit of the battery charger.

12 . The method of claim 9 , further comprising:
applying, by the controller device, a signal to the sense terminal of the battery pack; measuring, by the controller device, a transient response of the battery pack to the applied signal; measuring the voltage between the sense terminal of the battery pack and an input to a controller in response to applying the signal at a first time instance; and measuring the voltage between the sense terminal of the battery pack and the input of the controller in response to applying the signal at a subsequent time instance.

13 . The method of claim 12 , further comprising:
computing a value of the transient response over the first and subsequent instances of time.

14 . The method of claim 9 , wherein determining the temperature of the battery pack comprises:
measuring, by the controller, a value of resistance of the thermistor; and determining, by the controller, the transient response of the battery pack based on the value of resistance of the thermistor.

15 . The method of claim 14 , wherein the battery pack further includes a capacitor and an inductor and the method further comprises:
determining, by the controller, the transient response of the battery pack to the signal based on the resistance of the thermistor, inductance of the inductor, and capacitance of the capacitor.

16 . A charging device configured to charge a rechargeable battery housed in a battery pack, comprising at least one rechargeable electrochemical cell, the device comprising:
a charging compartment configured to receive the battery, the charging compartment having electrical contacts configured to be coupled to respective terminals of the battery; and a controller configured to:
receive an interrupt signal triggered upon: (i) insertion of the battery pack or (ii) controller device startup with the battery pack already installed;
measure a resistance value at the sense terminal; and
determine the temperature of the battery pack based on the measured resistance.

17 . The device of claim 16 wherein:
the controller is further configured to:
apply a signal to the sense terminal of the battery pack, and
measure a transient response of the battery pack to the applied signal; and

the device further comprises:
a capacitor coupled to a first input of the controller; and
a resistor coupled to an output terminal of the controller device, the output terminal supplying the signal to the battery pack.

18 . The device of claim 16 wherein the controller is configured to determine the transient response of the battery pack to the signal by:
τ BP1 =R th ∥R pd ∥R pu ×( C _ a/d )

where R th is a resistor in the battery pack R pd and R pu are resistors coupled to the output terminal and a voltage supply of the controller, respectively, and C_ a/d is the capacitor coupled to the first input of the controller.

19 . The device of claim 16 wherein the controller is configured to determine the transient response of the battery pack to the signal by:
τ BP1 =R th ∥R pd ∥R pu ×( C _ a/d +C _ bp2 )

where R th is a resistor in the battery pack R pd and R pu are resistors coupled to the output terminal and a voltage supply of the controller, respectively, C_ a/d is a capacitor coupled to the first input of the controller and C_ bp2 is a capacitor coupled to a terminal of the battery pack in parallel with the resistor R th .

20 . A charging device configured to charge a rechargeable battery housed in

Assignees

• Duracell Us Operations Inc

Inventors

• Dvorkin Elik
• Gajjar Tanmay P

Classifications

• H01M10/486 Primary

  for measuring temperature · CPC title

• H02J7/977

  of the battery · CPC title

• H02J7/751

  concerning the insertion or the connection of the batteries · CPC title

• H02J7/485

  with provisions for charging different types of batteries · CPC title

• H02J7/96

  in response to battery voltage · CPC title