Rechargeable battery evaluation

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 of rechargeable lithium battery, while the comparative evaluation is a comparison of a certain performance parameter for a battery with the same nominal capacity of two or more brands. The evaluation of rechargeable batteries is an important means to describe the objective situation of the battery. Under normal circumstances, the evaluation of rechargeable batteries requires special testing equipment, so it is better to test in the laboratory, which can reduce the error.

Whether it is self-evaluation or comparative evaluation, there are two preconditions for the evaluation of rechargeable batteries. One is that the working temperature is in the normal temperature range, and the other is that the rechargeable battery must be new.

For the self-assessment of rechargeable battery evaluation, the focus of battery manufacturers is often not the same: some include all performance parameters, some test only the parameters related to capacity, and some will add safety performance based on this test.

However, for comparative evaluation, it is basically around the parameters related to capacity. The preconditions at this time, in addition to the new power, should pay attention to the consistency of all the setting conditions, such as temperature, current, voltage, rest time, cycle times, test cabinet model, etc, all rechargeable battery evaluation environment must be the same of.

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 is measured by 0.2C discharge. Within the specified number of cycles, the weighted average of each recorded power is the actual capacity. The closer the actual capacity is to the nominal capacity, the more “true” the battery is.

2. Evaluate battery life. On the basis of the actual capacity evaluation of the battery, the actual capacity and the nominal capacity of each battery are successively compared to obtain the respective capacity attenuation rates, thereby evaluating the battery life.

3. Evaluation self-discharge: a certain period of time for a rechargeable battery evaluation cycle, has been placed on the cut-off voltage of the rechargeable battery, to see the change in battery capacity. Pay attention to this process: each brand should select several batteries, because there is a problem of battery discharge balance. Even if the overall self-discharge of rechargeable batteries of different brands is close to the evaluation results of the rechargeable battery, the battery with poor consistency can be considered to have poor battery capacity for a long time.

The evaluation of rechargeable batteries is a serious and scientific work. The staff should not only record the data of the rechargeable battery evaluation, but also strengthen the data processing and digital analysis capabilities of the rechargeable battery evaluation, so as to better provide accurate services for battery users.

The page contains the contents of the machine translation.