Estimation Method for Residual Discharging Time of Batteries

• US 20110260692A1
• Filed: 11/18/2010
• Published: 10/27/2011
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Ablerex Electronics Company Limited (Ablerex Overseas Corporation Limited)
• Original Assignee: Ablerex Electronics Company Limited (Ablerex Overseas Corporation Limited)
• Inventors: Sun, Yu-Hua, Chiang, Wen-Jung, Chou, Hung-Liang, Wu, Chin-Chang
• Granted Patent: US 8,878,489 B2
• Time in Patent Office: Days
• US Class Current: 320/136
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/3832 without measurement of battery voltage
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery

Abstract

An estimation method for residual discharging time of batteries includes the steps of: providing a set of battery-discharge-current intervals and a set of battery-discharge equations, setting discharge time of each battery-discharge-current intervals zero; detecting a discharge current, voltage and time of batteries; judging whether the discharge current exceeding all of the battery-discharge-current intervals; selecting one of the battery-discharge-current intervals and the associated battery-discharge equation according to the detected discharge current; calculating an estimation of residual discharging time; accumulating and recording the discharge time; judging whether the discharge voltage being lower than a predetermined value and calculating an estimation error of the residual discharging time; adjusting parameters of the battery-discharge equation for reducing the estimation error of the residual discharging time if the estimation error is greater than a predetermined error value.

Claims

1. An estimation method for a residual discharging time of batteries, comprising the steps of:

A. setting a plurality of battery-discharge-current intervals and battery-discharge equations thereof, each of the battery-discharge equation corresponding to the associated battery-discharge-current interval, further setting discharge time of each of the battery-discharge-current intervals zero;

B. detecting a discharge current, a discharge time and a discharge voltage of the batteries;

C. judging whether the discharge current exceeding all of the battery-discharge-current intervals, terminating the whole procedure if the discharge current exceeding all of the battery-discharge-current intervals;

D. selecting one of the battery-discharge equations corresponding to the associated battery-discharge-current interval according to the detected discharge current;

E. calculating the residual discharging time of the batteries;

F. accumulating and recording the discharge time of the associated battery-discharge-current interval corresponding to the selected battery-discharge equation;

G judging whether the discharge voltage being lower than a predetermined value, and returning to the step B if the discharge voltage is higher than the predetermined value;

H. calculating an estimation error of the residual discharging time when the discharge voltage is lower than a predetermined value;

I. judging whether the estimation error being greater than a predetermined error value, and terminating the whole procedure if the estimation error is lower than the predetermined error value;

J. adjusting parameters of the selected battery-discharge equation if the estimation error is greater than the predetermined error value.

2. The estimation method for the residual discharging time of the batteries as defined in claim 1, wherein the battery-discharge equations are Peukert equations.

3. The estimation method for the residual discharging time of the batteries as defined in claim 2, wherein the Peukert equation for calculating an initial residual discharging time is

t_p=K/Iⁿ

where t_p is the initial residual discharging time of batteries, K and n are parameters of Peukert equation, and I is the discharge current;

an equation for calculating the residual discharging time is

t_rm=t_p−

t_sm

where t_rm a real-time discharge residual time of batteries and t_sm is the accumulation of the residual discharging time.

4. The estimation method for the residual discharging time of the batteries as defined in claim 1, wherein, in the step H:

calculating the estimation error of the residual discharging time when the discharge voltage is lower than the predetermined value of the discharge voltage, the estimation error of the residual discharging time equals the calculated residual discharging time.

5. The estimation method for the residual discharging time of the batteries as defined in claim 2, wherein, in the step J:

adjusting parameters of the associated battery-discharge equation if the estimation error is greater than the predetermined error value, a parameter “

K”

of the Peukert equation is calculated in the form of

K=(t_p*Error(%)*Φ

+t_p)*Iⁿ□

0□

φ

□

1□

where K and n are the parameters of Peukert equation, t_p is the initial residual discharging time, Error(%) is an estimation error of the residual discharging time, I is a discharge current, and φ

is an adjustment ratio value.

6. The estimation method for the residual discharging time of the batteries as defined in claim 5, wherein the adjustment ratio value Φ

is a product of the discharge time and a mean value of the discharge current within the associated battery-discharge-current interval corresponding to the associated Peukert equation, and then the product is divided by the discharge capacity of the batteries, and the mean value of the discharge current is an average of a maximum and a minimum of the discharge current within the associated battery-discharge-current interval corresponding to the selected Peukert equation.