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DL / T 724-2000 "Electricity System DC Power Supply and Maintenance Technical Regulations" in Article 5.3, GB / T19826-2005 "General Technical Conditions and Safety Requirements for Electric Power Engineering DC Power Supply" Article 5.2 and 6.3 In the second, the technical indicators and test methods for the voltage regulator accuracy, the steady current accuracy, the ripple coefficient, the charging machine efficiency, and the battery capacity have clear provisions and technical requirements. The test content mainly changes the charger AC input voltage in the rated voltage ± 10% by the pressure regulator (e.g., transformer), and causes the DC output voltage and output current of the charger in the specified range by load adjustment means (such as discharge resistance). Internal change (voltage adjustment ranges from 90% to 115%, current