The Influence of Cell Size on Dynamic Charge Acceptance Tests in Laboratory Lead‐Acid Cells

Abstract

This study subjected laboratory‐scale test cells to testing methods for dynamic charge acceptance (DCA) that have recently been developed and published for 12 V automotive batteries, particularly enhanced flooded batteries (EFB). The main focus of the study lies on the scaling and geometry effects of different test cell compositions as well as the comparability between the DCA testing methods. The test cells for this study are extracted from industrially manufactured automotive batteries; each cell had either a full set of plates, or a reduced, negative‐limited set of plates. DCA measurements are performed according to SBA S0101:2014, EN 50 342‐6:2015, and a run‐in DCA drive cycle test. The results indicate that DCA generally increases as plate count falls. The correlation between short DCA tests and run‐in DCA under realistic operating conditions is as weak for individual cells as it is known to be for entire batteries. However, DCA stabilized somewhat more quickly in test cells than in batteries.

Electrochemical Impedance Spectroscopy as an Analytical Tool for the Prediction of the Dynamic Charge Acceptance of Lead-Acid Batteries

“…The DCA test results according to EN 50342-6:2015 for Type 1 EFB − C, Type 1 EFB + C and Type 2 EFB + C are shown in Figure 2a-c comparing the complete cell, the middle size cell and the small size cell. The DCA results have already been shown and discussed in [16] and will be compared with the EIS measurements within the next sections. The charge currents according to EN 50342-6:2015 are increasing in the following order: Type 1 EFB − C < Type 1 EFB + C < Type 2 EFB + C. This trend is valid for all cell layouts.…”

“…The DCA is the result of three parts: namely, after charge (I c ) at 80% SoC, discharge history (I d ) at 90% SoC and during real start-stop micro cycles (I r ) at 80% SoC. Further explanations of the test usage at the cell level are given in [16], along with a quantitative comparison with other charge acceptance tests.…”

Comparison of Dynamic Charge Acceptance Tests on Lead–Acid Cells for Carbon Additive Screening

“…This observation is unexpected and opposite of a parallel study conducted with different 2 V lead–acid cells, which examined the correlation between cell layout and DCA. [ 23 ] As the CA in the SBA test is determined after discharge history, the CA according to the SBA standard is expected to be higher than that obtained from the EN test, which is executed after charge, discharge, and during the course of several microcycles. The reason that the trend is the opposite in this study might be due to the electrical test order.…”

“…Further details about the test procedure can be found in the literature. [23] In this test, the following parameters had to be adjusted for the small laboratory test cells. For 12 V batteries, the change in the OCV of 1% SoC, known as the dV value, is generally between 10 and 15 mV.…”

“…In case of long‐term testing, the run‐in DCA test (test B) developed by Ford was executed. The detailed procedure of these three tests can be found elsewhere [ 23 ] and a brief explanation of the tests is given below. In the rest of the article, the CA test 2 (SBA S0101:2014), the DCA (EN 50342‐6:2015), and the run‐in DCA (test B) will be referred to SBA, EN, and run‐in test, respectively.…”