CIRCUIT-BASED METHOD FOR ESTIMATING BATTERY CAPACITY

• US 20110208453A1
• Filed: 02/23/2011
• Published: 08/25/2011
• Est. Priority Date: 02/23/2010
• Status: Abandoned Application

• Current Assignee: Jiucai Zhang, Song Ci
• Original Assignee: Jiucai Zhang, Song Ci
• Inventors: Ci, Song, Zhang, Jiucai
• Application Number:
  US13/033,519
• Publication Number:
  US 20110208453A1
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables

Abstract

A method for providing state of charge (SOC) estimations is disclosed. The method may comprise: receiving a battery having a nominated capacity; measuring an initial SOC of the battery; discharging the battery and measuring a sequence of time-based discharge characteristics; measuring a total operating time and a total consumed capacity; providing a set of relationship equations derived from a circuit-based battery model having a variable capacitor; utilizing a computing module to perform data fitting of the set of relationship equations based on: the initial SOC, the nominated capacity, the total operating time, the total consumed capacity, and the sequence of discharge characteristics, the computing module being configured for determining values for a plurality of parameters of the set of relationship equations through said data fitting; and obtaining a remaining capacity estimation equation based on the set of relationship equations after the values for the plurality of parameters are determined.

Claims

1. A method for providing remaining capacity estimations, the method comprising:

receiving a battery, the battery having a manufacturer nominated capacity;

measuring an initial state of charge (SOC) of the battery;

discharging the battery and measuring a sequence of time-based discharge characteristics of the battery during the discharge of the battery;

measuring a total operating time of the battery and a total consumed capacity;

providing a set of relationship equations, the set of relationship equations being derived from a circuit-based battery model having a variable capacitor;

utilizing a computing module to perform data fitting of the set of relationship equations based on;

the initial SOC, the manufacturer nominated capacity, the total operating time, the total consumed capacity, and the sequence of time-based discharge characteristics, the computing module being configured for determining values for a plurality of parameters of the set of relationship equations through said data fitting; and

obtaining a remaining capacity estimation equation based on the set of relationship equations after the values for the plurality of parameters are determined through said data fitting.

2. The method of claim 1, further comprising:

receiving a second battery, the second battery being of the same type as the first mentioned battery;

determining a discharge time since last full charge of the second battery; and

estimating a remaining capacity of the second battery based on the remaining capacity estimation equation and the discharge time since last full charge.

3. The method of claim 1, wherein the sequence of time-based discharge characteristics of the battery comprises as least one of:

a sequence of time-based discharge current of the battery;

a sequence of time-based output voltage of the battery; and

a sequence of time-based accumulated consumed capacity.

4. The method of claim 3, wherein the set of relationship equations are defined as:

5. The method of claim 4, wherein the remaining capacity estimation equation is defined as:

6. The method of claim 1, wherein the battery is fully charged when the battery is received, and the battery is fully discharged when said discharge of the battery is completed.

7. A system for providing remaining capacity estimation for a given type of battery, the system comprising:

a measurement module for measuring performance of a battery which represents the given type of battery, the measurement module configured for;

measuring a full capacity of the battery and an initial state of charge (SOC) of the battery;

discharging the battery and measuring a sequence of time-based discharge characteristics of the battery during the discharge of the battery; and

measuring a total operating time of the battery and a total consumed capacity;

an analysis module for analyzing the performance of the battery, the analysis module configured for;

providing a set of relationship equations, the set of relationship equations being derived from a circuit-based battery model having a variable capacitor;

performing data fitting of the set of relationship equations based on;

the initial SOC, the manufacturer nominated capacity, the total operating time, the total consumed capacity, and the sequence of time-based discharge characteristics; and

determining values for a plurality of parameters of the set of relationship equations through said data fitting; and

an estimation module for obtaining a remaining capacity estimation equation based on the set of relationship equations after the values for the plurality of parameters are determined through said data fitting.

8. The system of claim 7, wherein the estimation module is further configured for:

receiving another battery of the given type of battery;

determining a discharge time since last full charge of the other battery; and

estimating a remaining capacity of the other battery based on the remaining capacity estimation equation and the discharge time since last full charge.

9. The system of claim 7, wherein the sequence of time-based discharge characteristics of the battery comprises as least one of:

a sequence of time-based discharge current of the battery;

a sequence of time-based output voltage of the battery; and

a sequence of time-based accumulated consumed capacity.

10. The system of claim 9, wherein the set of relationship equations are defined as:

11. The system of claim 10, wherein the remaining capacity estimation equation is defined as:

12. A method for providing remaining capacity estimation for a multi-cell battery, the multi-cell battery having a plurality of battery cells connected in accordance to a cell topology, the method comprising:

determining at least one battery type utilized in the multi-cell battery;

obtaining a remaining capacity estimation equation for each one of the at least one battery type;

mapping the cell topology to at least one of;

a series system having a plurality of battery components connected in series, and a parallel system having a plurality of battery components connected in parallel; and

estimating the remaining capacity for the multi-cell battery, wherein the remaining capacity for the multi-cell battery is the minimum of the remaining capacities of the plurality of battery components when the plurality of battery components are connected in series, and the remaining capacity for the multi-cell battery is the sum of the remaining capacities of the plurality of battery components when the plurality of battery components are connected in parallel.

13. The method of claim 12, wherein at least one of the plurality of battery components is a single-cell battery.

14. The method of claim 12, wherein at least one of the plurality of battery components comprises a plurality of single-cell batteries.

15. The method of claim 12, wherein obtaining a remaining capacity estimation equation for each particular battery type further comprising:

determining a manufacturer nominated capacity for the particular battery type;

measuring an initial state of charge (SOC) for the particular battery type;

discharging a battery of the particular battery type and measuring a sequence of time-based discharge characteristics of the battery during the discharge of the battery;

measuring a total operating time of the battery and a total consumed capacity;

providing a set of relationship equations, the set of relationship equations being derived from a circuit-based battery model having a variable capacitor;

utilizing a computing module to perform data fitting of the set of relationship equations based on;

the initial SOC, the manufacturer nominated capacity, the total operating time, the total consumed capacity, and the sequence of time-based discharge characteristics, the computing module being configured for determining values for a plurality of parameters of the set of relationship equations through said data fitting; and

obtaining a remaining capacity estimation equation based on the set of relationship equations after the values for the plurality of parameters are determined through said data fitting.

16. The method of claim 15, wherein the sequence of time-based discharge characteristics of the battery comprises as least one of:

a sequence of time-based discharge current of the battery;

a sequence of time-based output voltage of the battery; and

a sequence of time-based accumulated consumed capacity.

17. The method of claim 16, wherein the set of relationship equations are defined as:

18. The method of claim 17, wherein the remaining capacity estimation equation is defined as: