After the HZNZ-100 measurement is completed, five test conclusions will be given: excellent, good, outdated, deteriorated, and abnormal. The judgment logic behind these five words, as well as the corresponding disposal suggestions, are the core of converting internal resistance test results into actual maintenance decisions.

The meanings of the five conclusions

The instrument compares the measured internal resistance with the reference internal resistance (provided by the manufacturer or customized by the user), and combines it with the terminal voltage to draw a comprehensive conclusion:

Excellent: The internal resistance is within the reference range, the terminal voltage is normal, and the battery is in good condition, so no special attention is needed.

Good: The internal resistance has slightly increased, but it is still within an acceptable range. It is recommended to focus on this section during the next routine inspection.

Backward: The internal resistance is significantly higher than the reference value (usually 1.5 to 2 times higher than the reference value), indicating that the battery has shown significant performance degradation and is a "shortcoming" in the entire battery pack. When discharging the entire group, the lagging battery will first reach the termination voltage, dragging down the effective discharge time of the entire group. It is necessary to pay close attention to and plan for replacement.

Deterioration: The internal resistance is severely high, the battery plates are severely vulcanized, and the actual usable capacity has significantly decreased, approaching a scrap state. Replacement should be arranged as soon as possible.

Exception: Extreme abnormal values in internal resistance or voltage may be due to poor contact of the test clip, open circuit of the battery (internal open circuit), or complete failure of the battery. It is necessary to first investigate and test the connection issue. If the wiring is correct but still abnormal, then the battery itself has a serious defect.

The importance of reference internal resistance

The accuracy of the above conclusion depends on whether the reference internal resistance setting is correct. The instruction manual clearly states that the reference internal resistance should be based on the data provided by the battery manufacturer. If the manufacturer does not provide it, please refer to the built-in database of the instrument. Filling in the reference internal resistance incorrectly (such as using the reference internal resistance of a 100Ah battery to evaluate a 200Ah battery) will result in a complete deviation of all conclusions and render the evaluation meaningless.

Suggestions for the disposal of outdated batteries

After discovering outdated batteries, their location and internal resistance should be recorded to compare and evaluate the degradation rate with historical data. It is not necessary to replace a single section immediately after it falls behind. It can be combined with a comprehensive evaluation of capacity nuclear discharge tests to confirm that the capacity has decreased to below 80% of the rated value before replacement, taking into account economic considerations. If the number of outdated batteries exceeds 10% of the entire group, it is recommended to evaluate the replacement of the entire group.