Determination of battery type

• US 10,126,371 B2
• Filed: 11/21/2014
• Issued: 11/13/2018
• Est. Priority Date: 11/22/2013
• Status: Active Grant

• Current Assignee: Assa Abloy AB
• Original Assignee: Assa Abloy AB
• Inventors: Jonsson, Tomas
• Primary Examiner(s): Nguyen, Tung X
• Assistant Examiner(s): Frederiksen, David
• Application Number:
  US15/037,800
• Publication Number:
  US 20160291092A1
• Time in Patent Office: 1,453 Days
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/378 specially adapted for the type of battery or accumulator
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H02J 7/00041 in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/35 with light sensitive cells

Abstract

It is presented a method for determining a battery type of a battery set powering a host device, the battery set comprising at least one exchangeable battery. The method is performed in a battery type determiner and comprises the steps of: measuring a voltage of the battery set, yielding a voltage measurement; determining charge depletion of the battery set; storing the voltage measurement and the charge depletion; repeating the steps of measuring, determining charge depletion and storing until an exit condition is true; and determining the battery type based on the stored voltage measurements and the stored charge depletion. A corresponding battery type determiner, host device, computer program and computer program product are also presented.

Claims

1. A method for determining a battery type of a battery set powering a host device, the battery set comprising at least one exchangeable battery, the method being performed in a battery type determiner and comprising the steps of:

measuring a voltage of the battery set with a voltage sensor, yielding a voltage measurement;

determining charge depletion of the battery set;

storing the voltage measurement and the charge depletion in a memory device;

repeating the steps of measuring, determining charge depletion and storing until an exit condition is true; and

determining the battery type based on the stored voltage measurements and the stored charge depletion by;

calculating a rate of change of the voltage in relation to the charge depletion based on the stored voltage measurements and the stored charge depletion;

determining the battery type to be an alkaline battery when the rate of change is greater than a threshold rate; and

determining the battery type to be a lithium battery when the rate of change is less than a threshold rate.

2. The method according to claim 1, wherein the step of determining the battery type further comprises the sub-steps of:

comparing the stored voltage measurements in relation to charge depletion with curves of voltage in relation to charge depletion for a plurality of battery types;

selecting the curve which best matches the stored voltage measurements in relation to charge depletion; and

determining the battery type of the battery set to be the battery type of the selected curve.

3. The method according to claim 2, wherein in the sub-step of comparing, the curves comprise a curve for a battery set comprising mixed battery types.

4. The method according to claim 1, wherein the step of determining the battery type further comprises:

when the battery type is determined to be a lithium battery, determining whether the battery set is rechargeable or not based on an initial voltage measurement.

5. The method according to claim 1, wherein the step of determining charge depletion comprises measuring change of charge depletion when the host device is an active state, and estimating change of charge depletion when the host device is in a standby state based on a constant charge depletion per time unit.

6. The method according to claim 5, wherein the step of determining charge depletion comprises measuring an increase of charge when the battery set is charged.

7. The method according to claim 1, wherein the exit condition is true when the charge depletion has reached a threshold charge depletion.

8. The method according to claim 1, wherein the exit condition is true when the voltage of the battery set has reached a voltage level determined to end the measurements.

9. The method according to claim 1, wherein the exit condition is true when a specific amount of time has passed.

10. The method according to claim 1, further comprising the step of:

determining a status of the battery based on the determined battery type.

11. The method according to claim 10, wherein the first iteration of determining a status of the battery comprises determining whether the battery was new when the method started.

12. The method according to claim 10, further comprising the step of:

warning that the battery set needs to be replaced when the battery status indicates that the battery set is near the end of operation.

13. A battery type determiner for determining a battery type of a battery set arranged to power a host device, the battery set comprising at least one exchangeable battery, the battery type determiner comprising:

a voltage sensor arranged to measure a voltage of the battery set, yielding a voltage measurement;

a charge depletion sensor arranged to determine a charge depletion of the battery set;

a memory arranged to store the voltage measurement and the charge depletion; and

a controller arranged to repeat measuring the voltage and storing the voltage measurement until an exit condition is true, to thereafter determine the battery type based on the stored voltage measurements and the stored charge depletion by;

calculating a rate of change of the voltage measurement in relation to the charge depletion based on the stored voltage measurements and the stored charge depletion, which are both stored in the memory;

determining the battery type to be an alkaline battery when the rate of change is greater than a threshold rate of change; and

determining the battery type to be a lithium battery when the rate of change is less than the threshold rate of change.

14. A host device comprising the battery type determiner according to claim 13, wherein the battery type determiner is arranged to determine the battery type of the battery set.

15. The host device according to claim 14, wherein the host device is a lock device for restricting physical access to a confined space.

16. The host device according to claim 14, wherein the exit condition is true when the voltage of the battery set has reached a voltage level determined to end the measurements.

17. A non-transitory computer-readable medium comprising a computer program stored thereon for determining a battery type of a battery set powering a host device, the battery set comprising at least one exchangeable battery-, the computer program comprising computer program code which, when run on a battery type determiner causes the battery type determiner to:

measure a voltage of the battery set, yielding a voltage measurement;

determine charge depletion of the battery set;

store the voltage measurement and the charge depletion;

repeat the instructions to of measure, determine charge depletion and store until an exit condition is true; and

determine the battery type based on the stored voltage measurements and the stored charge depletion by;

calculating a rate of change of the voltage measurement in relation to the charge depletion based on the stored voltage measurements and the stored charge depletion;

determining the battery type to be an alkaline battery when the rate of change is greater than a first threshold rate of change; and

determining the battery type to be a lithium battery when the rate of change is less than a second threshold rate of change.

18. The non-transitory computer-readable medium of claim 17, wherein the host device comprises a lock device for restricting physical access to a confined space.

19. The non-transitory computer-readable medium of claim 17, wherein the first threshold rate of change and the second threshold rate of change are the same value.

20. The non-transitory computer-readable medium of claim 17, wherein the exit condition is true when the voltage of the battery set has reached a voltage level determined to end the measurements.