Electric vehicle battery monitoring system

Patent metadata

Field	Value
Publication number	US-10436845-B2
Application number	US-201615057739-A
Country	US
Kind code	B2
Filing date	Mar 1, 2016
Priority date	Mar 1, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

Systems and methods for monitoring and controlling a battery are disclosed. Systems can include a battery having an output voltage and an output current when delivering power, a load driven by power delivered from the battery, battery output voltage and current sensing circuits, and processing circuitry coupled to the battery output voltage and current sensing circuits. The processing circuitry may be configured to obtain sensed battery output voltage and current values, and to estimate values for at least three battery state parameters by concurrently fitting the voltage and current values to at least two different equations.

First claim

What is claimed is:

1. A battery powered apparatus comprising:
a battery comprising one or more electrochemical cells, the battery having an output voltage and an output current when delivering power;
a load driven by power delivered from the battery;
a battery output voltage sensing circuit;
a battery output current sensing circuit; and
processing circuitry coupled to the battery output voltage sensing circuit and the battery output current sensing circuit, the processing circuitry configured to obtain sensed battery output voltage values and sensed battery output current values at defined intervals and to estimate values for at least three battery state parameters of a plurality of battery state parameters at particular times when the battery is delivering power to the load, the plurality of battery state parameters including an open circuit voltage (V oc ), a series resistance (R s ), a first resistance (R 1 ), a first capacitance (C 1 ), a second resistance (R 2 ), and a second capacitance (C 2 ), wherein each of the at least three battery state parameters varies over time as the battery is used to drive the load;
wherein estimating the at least three battery state parameters comprises concurrently fitting sensed battery output voltage values and sensed battery output current values and/or data derived using the sensed battery output voltage values and sensed battery output current values to at least two different equations, wherein each of the at least two different equations are defined at least in part by different subsets of the at least three battery state parameters.

2. The battery powered apparatus of claim 1 , wherein one or more of the at least two different equations is a linear equation with a slope and an intercept defined at least in part by one or more of the at least three battery state parameters.

3. The battery powered apparatus of claim 1 , wherein estimating comprises storing current estimated values for the at least three battery state parameters, obtaining additional sensed battery output voltage values and sensed battery output current values, and updating the current estimates of the at least three battery state parameters based at least in part on the additional sensed battery output voltage values and sensed battery output current values.

4. The battery powered apparatus of claim 1 , wherein the estimation of at least one of the battery state parameters is dependent on the estimated value of at least one other battery state parameter.

5. The battery powered apparatus of claim 1 , wherein the processing circuitry is configured to estimate values of at least six battery state parameters and wherein the at least two different equations include at least three linear equations.

6. The battery powered apparatus of claim 5 , wherein the three linear equations comprise:

(

V
s

)

=

R
s

⁡

(

I
b

)

+

V
oc

(
1
)

(

∫

I
b

V
1

)

=

1

R
1

⁢

(

∫

V
1

V
1

)

+

C
1

(
2
)

(

∫

I
b

V
2

)

=

1

R
2

⁢

(

∫

V
2

V
2

)

+

C
2

,

(
3
)

wherein R s , V oc , R 1 , C 1 , R 2 , and C 2 are components of a battery equivalent circuit, wherein R 1 and C 1 are components of a first series RC circuit and R 2 and C 2 are components of a second series RC circuit and wherein equations (2) and (3

Assignees

• Faraday&Future Inc
• Faraday & Future Inc

Inventors

• Weicker Phillip John
• Heinen Garrett David

Classifications

• G01R31/3842

  combining voltage and current measurements · CPC title

• G01R31/3648 Primary

  comprising digital calculation means, e.g. for performing an algorithm · CPC title

• B60L58/12

  responding to state of charge [SoC] · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title