Self-evaluation of rechargeable batteries

The rechargeable battery evaluation is divided into two parameter systems: self-evaluation and comparative evaluation. Self-evaluation is to evaluate some of the performance of a brand's rechargeable lithium battery, while comparative evaluation is to compare a certain performance parameter for two or more batteries with the same nominal capacity of two or more brands. Rechargeable battery evaluation is an important means of describing the objective situation of the battery. Under normal circumstances, the evaluation of a rechargeable battery requires a special detection device, so it is good to test in the laboratory, so that the error can be reduced.

Whether it is self-evaluation or comparative evaluation, the evaluation of rechargeable batteries must have two preconditions. One is that the working temperature is within room temperature, and the other is that the rechargeable battery must be new.

Battery manufacturers often do not have the same emphasis on self-evaluation in rechargeable battery evaluation: some include all performance parameters, others test only volume-related parameters, and some add safety performance tests to this.

However, for comparative evaluation, it is basically centered on volume-related parameters. At this time, the preconditions, in addition to all new electricity, should pay attention to the consistency of all setting conditions, such as temperature, current, voltage, static time, number of cycles, test cabinet type and other rechargeable battery evaluation environment must be the same.

In the comparative evaluation, the main test three parameters:

1, the actual capacity of the battery and its difference from the nominal capacity. The actual capacity of the test is based on 0.2 C discharge. Within the specified number of cycles, the weighted average of each recorded charge is the actual capacity. The closer the actual capacity is to the nominal capacity, the more "true" the battery is.

2, assess battery life. On the basis of the actual capacity evaluation of the battery, the actual capacity of each battery is compared with the nominal capacity one by one, and the respective capacity attenuation rates are obtained, and the battery life is measured.

3, the evaluation of self-discharge: a certain period of time for a rechargeable battery evaluation cycle, all the time to the rechargeable battery off the voltage, to see the battery capacity changes. This process should be noted: each brand to select a number of batteries, because there is a battery discharge equilibrium problem. Even if the overall self-discharge of different brands of rechargeable batteries is close to that of rechargeable batteries, batteries with poor consistency can be considered to have poor long-term power retention.

Recharged-cell evaluation is a serious and scientific task. Staff must not only record the data of rechargeable battery evaluation, but also strengthen the data processing and digital analysis capabilities of rechargeable battery evaluation, so as to better provide accurate services to battery users.

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