The purpose of initial charging is to put the lead oxide generated by long-term contact with air on the cathode plate electrolyte It reacts with sulfuric acid to become lead sulfate, and during the initial charging process, lead sulfate is reduced to fluffy lead. Because this kind of lead sulfate is more, it needs to be charged for a long time. [1] ① Requirements for AC power supply
During the initial charging period of the storage battery, ensure that the AC power supply is not interrupted within 75 hours. In particular, it is not allowed to stop charging within 24 hours after starting charging. Therefore, it is required to have at least two lines of mains power or one line of reliable mains power weak part oil turbine generator set. The voltage shall be within the range of 90-110% (342~418 V) of the rated value, and the phase connection shall be correct. The rectifier can work normally.
② Requirements for charging equipment
The over-voltage and over-current protection and fuse of the rectifier must be checked and adjusted. In case of failure, it shall be able to stop automatically and send alarm signals. The output of manual and automatic adjustment is normal, and the voltage and current stabilization shall meet the indicators specified by the manufacturer. The automatic current stabilizing part shall be used for load test for a certain time (not less than 2 hours) to ensure safety during charging. After the installation of all power equipment is completed, the initial charging can be carried out only after the wiring is correct, the insulation is good and the oil turbine generator set operates normally.
③ Requirements for concentrated sulfuric acid and distilled water and calculation of required quantity
The dilute sulfuric acid used for lead batteries must be pure, which is made by mixing pure sulfuric acid with distilled water (or pure water). The purity and impurity of the electrolyte have a great impact on the battery life. If it contains impurities, it is easy to generate natural discharge. The electrolyte contains more than 5% impurities, and it is possible to discharge the electricity within 24 hours. In particular, batteries that use the charging and discharging system are more harmful because they do not have supplementary charging. [2]
According to the initial charging record, the cumulative amount of electricity charged into the battery should be 5~6 times of the rated capacity of the battery. The terminal voltage of each battery is above 2.7 "-- 2.75 V. At this time, the electrolyte bubbles rise, the positive plate is dark brown, and the negative plate is light gray. It can be clearly seen from the lead bridge that half is brown and half is gray. After the specific gravity is adjusted, the voltage will not rise for three hours, which indicates that the battery has been charged. [2]
