The power industry standards of the People's Republic of China, DL/T724-2000 Technical Specification for Operation and Maintenance of Battery DC Power Supply Devices for Power Systems, Section 5.3, and IEEE Std 1188-1996 IEEE Recommended Methods for Maintenance, Testing, and Replacement of Valve Regulated Lead Acid (VRLA) Batteries for Station Use, Section 6.1, clearly stipulate acceptance testing: Only batteries that pass acceptance testing can be put into operation.

Acceptance testing generally requires three cycles of constant current discharge at I10 (10 hour discharge rate discharge current), timely monitoring of individual voltage and total voltage to prevent over discharge. The purpose of acceptance testing is twofold: firstly, to check whether the battery pack meets the design requirements or factory rated value; The second is to undergo several cycles of deep charging and discharging, allowing the newly installed battery to enter normal working conditions. If a newly installed battery does not experience more than one deep discharge (100%) in more than a year, it will accelerate battery aging, increase internal resistance, and reduce capacity. The inconsistency of the entire battery group will become increasingly apparent, the charging and discharging capacity of the battery will become worse, the lifespan of the entire battery group will be shortened, and the possibility of permanent failure is particularly high.

Due to various factors such as manufacturing process, testing methods, and loading, unloading, and transportation, the discreteness (non consistency) of the entire batch of VRLA batteries is common, and there are certain differences in the terminal voltage and internal resistance of each battery. In order to achieve the best charging and discharging effect of the entire battery, deep discharge of the entire battery is an essential and important step before the battery pack is put into operation. Through deep discharge, batteries with performance that does not meet the acceptance standards can be selected, while the electrochemical performance of the entire set of batteries tends to be consistent.