AU2018432963A1

AU2018432963A1 - Abuse and over-discharge performance evaluation and capacity recovery method for lead-acid battery

Info

Publication number: AU2018432963A1
Application number: AU2018432963A
Authority: AU
Inventors: Wei Liu; Zhiqiang Liu; Hongliang Wu; Xiaoliang Xu; Kuiwang XUE; Baofeng Yang; Liufang ZENG
Original assignee: Shuangdeng Group Co Ltd
Current assignee: Shuangdeng Group Co Ltd
Priority date: 2018-07-19
Filing date: 2018-10-29
Publication date: 2020-04-16
Also published as: WO2020015226A1; CN109116246B; CN109116246A

Abstract

Disclosed in the present invention is an abuse and over-discharge performance evaluation for a lead-acid battery. The evaluation mainly obtains an abuse and over-discharge capacity rate Caod by means of an abuse and over-discharge performance test, and then obtains an over-discharge capacity attenuation rate Caoc by means of a cyclic over-discharge test. In the foregoing manner, the pros and cons of relevant design solutions and over-discharge capabilities are pre-evaluated. Also disclosed in the present invention is a capacity recovery method for a lead-acid battery after abuse and over-discharge. Said method activates a built-in active substance by means of deep discharge, thereby promoting backward battery capacity recovery. In general, the present invention employs a quantitative evaluation method which is simple and accurate, is timely, is beneficial for a guiding a design, and may significantly shorten the development cycle and reduce costs. By applying the present invention, a user may promptly optimize and adjust the operating efficiency of a matched battery pack.

Description

PERFORMANCE EVALUATION OF ABUSIVE OVERDISCHARGE OF LEAD-ACID BATTERY AND METHOD OF

CAPACITY RECOVERY

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to the technical field of lead-acid batteries, in particular to a performance evaluation of abusive over-discharge of lead-acid battery, and to a method of capacity recovery after the abusive over-discharge of backward battery.

[0003] 2. Description of the Related Art [0004] There is a “bucket effect” in the use of lead-acid battery packs, which means that backward battery pull down the performance indicators of others. Due to the lack of prior evaluation methods for backward batteries in the industry, especially the evaluation of abusive over-discharge of lead-acid batteries, there is also no method for capacity recovery of backward batteries. Therefore, the battery packs used in the project often fail to meet the expected performance indicators; if such technical problems are not solved well, it will easily lead to conflicts between the supply and demand sides. In reality, there are certain differences in cycle life, over-discharge capability and product consistency of lead-acid batteries produced according to different design schemes, while these differences cannot be quantitatively evaluated during the R & D and design stages; reliable samples can only be obtained by using the produced samples for physical testing.

Technical Issues [0005] In the prior art, although physical detection is easy to be implemented, the method is simple, and the data is accurate, however, the verification cycle is too long and the timeliness is poor, which is not conducive to guiding production. In addition, lead-acid batteries may cause minor performance differences due to the errors in the manufacturing process; as long as the performance indicators are not excessive, they are all qualified products. However, over-discharge and undercharge situations exist for the user during use, and such situations are likely to cause backward batteries. In view of the above two situations, it is necessary to research a performance evaluation of abusive over-discharge of lead-acid battery and method of capacity recovery, which is helpful for manufacturers to carry out comparative analysis and quantitative analysis of R & D solutions in a timely manner; since the analysis method is i

DESCRIPTION reasonable, accurate and reliable, and the blindness is reduced, the R & D cycle is shortened and the cost thereof is lowered. On the other hand, it is also convenient for the user to perform the battery capacity recovery in time, which creates a good basic condition for improving the operating efficiency of the battery.

SUMMARY OF THE INVNETION [0006] The invention mainly aims at the problem that the industry lacks a detection method for the performance of lead-acid batteries, and provides a performance evaluation of abusive over-discharge of lead-acid battery that is simple, easy to be implemented, and can be used for quantitative analysis. The invention further comprises a method of capacity recovery after the abusive over-discharge of backward battery.

[0007] The invention achieves the technical objectives by the following technical solutions.

[0008] A performance evaluation of abusive over-discharge of lead-acid battery, wherein the evaluation is performed in an environment of 25°C± 2°C, and the specific steps are as follows: [0009] 1.1 selecting six lead-acid batteries of the same specification in series to form a group according to the conventional configuration; first discharging with IwA current, and then charging with 2.35V per one, current-limiting of 2IioA for 16 hours;

[0010] 1.2 selecting one of the lead-acid batteries to discharge with IwA current for 4 hours alone, and then connecting it with other five fully-charged lead-acid batteries in series to form a battery pack;

[0011] 1.3 discharging the battery pack with IwA current until the voltage of the five fullycharged lead-acid batteries that had been fully charged drops to the total voltage of 5* 1.80V, and then stopping discharge to be left for 2 hours;

[0012] 1.4 continuously charging the battery pack with a constant voltage of 2.35V per one, current-limiting of2IwAfor 144 hours;

[0013] 1.5 when the battery pack is discharged from IwA current to the total voltage of 6* 1.80V, measuring the capacity and converting into the capacity value under the reference state of 25 °C;

[0014] 1.6 calculating the ratio of the actual discharge capacity to the rated capacity Cw of the battery pack, to obtain the abusive over-discharge capacity rate Caod;

[0015] 1.7 discharging the battery pack with IwA current, and the termination voltage is 6* 1.4V;

[0016] 1.8 charging the battery pack with a constant voltage of 6*2.35V, current-limiting of 21 wA for 36 hours;

DESCRIPTION [0017] 1.9 repeating steps 1.7 and 1.8 for 5 times in total;

[0018] 1.10 when the battery pack is discharged with IioA current to the termination voltage of 6* 1.80V, performing the capacity detection;

[0019] 1.11 calculating the ratio of the actual discharge capacity to the rated capacity of the battery pack, to obtain the cyclic over-discharge capacity attenuation rate Caoc.

[0020] A method of capacity recovery after the abusive over-discharge of lead-acid battery according to claim 1, wherein the improvement thereof is that the method is performed by the following steps:

[0021] 2.1 deeply discharging the abusive over-discharged backward battery with IioA current, and the termination voltage is 1.25 V;

[0022] 2.2 continuously charging with a constant voltage of 2.35V, current-limiting of 2IioA for 36 hours;

[0023] 2.3 repeating steps 2.1 and 2.2 for 3 times in total;

[0024] 2.4 discharging from IIOA current to the termination voltage of 1.80V, and performing the capacity detection; calculating the ratio of the actual discharge capacity to the rated capacity, to obtain the repaired capacity recovery rate Caor.

[0025] Advantageous Effects [0026] Compared with the prior art, the invention has the following advantageous effects: [0027] 1. the method is reasonable, the steps are simple, and the operability is good;

[0028] 2. the abusive over-discharge capacity rate and the cyclic over-discharge capacity attenuation rate are accurately obtained according to the test; this quantitative pre-evaluation method is highly accurate and is conducive to guiding the design in a timely manner, thereby reducing the cost and period of R & D;

[0029] 3. the invention provides a method for quickly evaluating the over-discharge performance of lead-acid battery for the user and a method of capacity recovery of backward battery, which can timely optimize and adjust the operating efficiency of the supporting battery pack.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0030] The invention will be further explained hereinafter according to the performance evaluation of abusive over-discharge of lead-acid battery with different design schemes.

[0031] Before the evaluation is performed, design scheme A and design scheme B are chosen to prepare samples separately. In the embodiment, the specification of the sample is: 2V, 200AH lead-acid battery, and the number is 9 each; six of each scheme are used for the

DESCRIPTION performance evaluation of abusive over-discharge of lead-acid battery and the method of capacity recovery of the invention, and the remaining three of each scheme are used for 100% DOD cycle life test.

[0032] A performance evaluation of abusive over-discharge of lead-acid battery, wherein design scheme A and design scheme B are chosen to prepare samples, the evaluation is performed in an environment of 25°C± 2°C, and the specific steps are as follows:

[0033] 1.1 selecting six lead-acid batteries of the same specification in series to form a group according to the conventional configuration; first discharging with IwA current, and then charging with 2.35V per one, current-limiting of 2IwA for 16 hours;

[0034] 1.2 selecting one of the lead-acid batteries to discharge with IwA current for 4 hours alone, and then connecting it with other five fully-charged lead-acid batteries in series to form a battery pack;

[0035] 1.3 discharging the battery pack with IwA current until the voltage of the five fullycharged lead-acid batteries that had been fully charged drops to the total voltage of 5* 1.80V, and then stopping discharge to be left for 2 hours;

[0036] 1.4 continuously charging the battery pack with a constant voltage of 2.35V per one, current-limiting of2IwAfor 144 hours;

[0037] 1.5 when the battery pack is discharged from IwA current to the total voltage of 6* 1.80V, measuring the capacity and converting into the capacity value under the reference state of 25 °C;

[0038] 1.6 calculating the ratio of the actual discharge capacity to the rated capacity Cw of the battery pack, to obtain the abusive over-discharge capacity rate Caod;

[0039] 1.7 discharging the battery pack with IwA current, and the termination voltage is 6* 1.4V;

[0040] 1.8 charging the battery pack with a constant voltage of 6*2.35V, current-limiting of 21 wA for 36 hours;

[0041] 1.9 repeating steps 1.7 and 1.8 for 5 times in total;

[0042] 1.10 when the battery pack is discharged with IwA current to the termination voltage of 6* 1.80V, performing the capacity detection;

[0043] 1.11 calculating the ratio of the actual discharge capacity to the rated capacity of the battery pack, to obtain the cyclic over-discharge capacity attenuation rate Caoc.

[0044] A method of capacity recovery after the abusive over-discharge of lead-acid battery, which must be performed after the above evaluation, and the specific steps are as follows:

DESCRIPTION [0045] 2.1 deeply discharging the abusive over-discharged backward battery with IioA current, and the termination voltage is 1.25 V;

[0046] 2.2 continuously charging with a constant voltage of 2.35V, current-limiting of 2IioA for 36 hours;

[0047] 2.3 repeating steps 2.1 and 2.2 for 3 times in total;

[0048] 2.4 discharging from IioA current to the termination voltage of 1.80V, and performing the capacity detection; calculating the ratio of the actual discharge capacity to the rated capacity, to obtain the repaired capacity recovery rate Caor.

[0049] After the samples of design scheme A and design scheme B were subjected to the above steps, the abusive over-discharge capacity rate Caod, the cyclic over-discharge capacity attenuation rate Caoc, and the repaired capacity recovery rate are obtained, respectively; the specific data are shown in the table below:

[0050] Data Comparison Table of Performance Evaluation of Abusive over-discharge and Capacity Recovery of Samples of Design Scheme A and Design Scheme B [0051]

Types	Sample of Design Scheme A	Sample of Design Scheme B	Conclusion
Abusive overdischarge Capacity Rate Caod	0.82	0.71	Sample of Design Scheme A is Better Than That of Design Scheme B: 15.5% Higher
Cyclic overdischarge Capacity Attenuation Rate Caoc	0.91	0.80	Sample of Design Scheme A is Better Than That of Design Scheme B: 13.7% Higher
Repaired Capacity Recovery rate	1.01	0.90	Sample of Design Scheme A is Better Than That of Design Scheme B: 12.2% Higher

DESCRIPTION [0052] In order to further verify the similarity between the test results of the invention and the actual situation, three samples reserved for design scheme A and design scheme B were taken for 100% DOD cycle life test, respectively; the specific test conditions and steps are as follows:

[0053] first discharging the lead-acid battery sample with 20A current until the termination voltage is 1.80V;

[0054] then continuously charging with a constant voltage of 7.05V, current-limiting of 40A for 16 hours;

[0055] repeating the above two steps until the capacity is less than 80% of the rated capacity.

[0056] Test results:

[0057] the depth of discharge of 100% DOD cycle life of the sample of design scheme A is 507 times, and the depth of discharge of 100% DOD cycle life of the sample of design scheme B is 302 times. By comparison, the sample of design scheme A is significantly better than the sample of design scheme B.

[0058] The invention adopts a quantitative evaluation method, which is simple and accurate, and has good timeliness; it is beneficial to further guide the design, thereby reducing the cost and period of R & D. By applying the invention, the user can recover the capacity after the abusive over-discharge of backward battery, which can timely optimize and adjust the operating efficiency of the supporting battery pack.

Claims

1.11 calculating the ratio of the actual discharge capacity to the rated capacity of the battery pack, to obtain the cyclic over-discharge capacity attenuation rate Caoc.

2. A method of capacity recovery after the abusive over-discharge of lead-acid battery according to claim 1, wherein the method is performed by the following steps:

2.1 deeply discharging the abusive over-discharged backward battery with IwA current, and the termination voltage is 1.25 V;

2.2 continuously charging with a constant voltage of 2.35V, current-limiting of 21 wA for 36 hours;

2.3 repeating steps 2.1 and 2.2 for 3 times in total;

i

1.10 when the battery pack is discharged with IwA current to the termination voltage of 6* 1.80V, performing the capacity detection;

1.9 repeating steps 1.7 and 1.8 for 5 times in total;

1.8 charging the battery pack with a constant voltage of 6*2.35V, current-limiting of 21 wA for 36 hours;

1.7 discharging the battery pack with IwA current, and the termination voltage is 6* 1.4V;

1.6 calculating the ratio of the actual discharge capacity to the rated capacity Cw of the battery pack, to obtain the abusive over-discharge capacity rate Caod;

1.5 when the battery pack is discharged from IwA current to the total voltage of 6* 1.80V, measuring the capacity and converting into the capacity value under the reference state of 25 °C;

1.4 continuously charging the battery pack with a constant voltage of 2.35V per one, current-limiting of2IwAfor 144 hours;

1.3 discharging the battery pack with IwA current until the voltage of the five fullycharged lead-acid batteries that had been fully charged drops to the total voltage of 5* 1.80V, and then stopping discharge to be left for 2 hours;

1.2 selecting one of the lead-acid batteries to discharge with IwA current for 4 hours alone, and then connecting it with other five fully-charged lead-acid batteries in series to form a battery pack;

1.1 selecting six lead-acid batteries of the same specification in series to form a group according to the conventional configuration; first discharging with IwA current, and then charging with 2.35V per one, current-limiting of 2IwA for 16 hours;

1. A performance evaluation of abusive over-discharge of lead-acid battery, wherein the evaluation is performed in an environment of 25°C± 2°C, and the specific steps are as follows:

2.4 discharging from IioA current to the termination voltage of 1.80V, and performing the capacity detection; calculating the ratio of the actual discharge capacity to the rated capacity, to obtain the repaired capacity recovery rate Caor.