1. Repair steps The repair of the battery can be divided into four steps: selection, judgment, repair and inspection: Selection is the preliminary selection of the battery, and the batteries that have no repair value are selected to reduce the blindness of the repair. Judgment-it is to check and judge the qualified batteries in the primary selection, and continue to eliminate the batteries that are difficult to repair; then according to the specific conditions of the battery, select the appropriate repair process to repair the battery. Repair-is to select the appropriate repair method and repair process to repair the battery with repair value. Inspection-is to measure the repaired battery, inspect the repair effect, and provide a basis for the use of the battery. 2. Selection of battery reference standards Battery repair is mainly aimed at sulphated batteries. For batteries that are physically damaged, such as short circuit, open circuit, plate softening, ruptured shape, aging, and scrapped batteries cannot be repaired, the preliminary selection criteria are as follows: (1) Good appearance, no swelling, deformation or leakage. (2) The battery leaves the factory within two years (see the batch number), and the battery used for more than two years has no repair value. (3) A battery with a capacity not less than 40% of the rated capacity, and a battery with a capacity lower than 40% of the rated capacity, cannot reach the ideal capacity value after repair. (4) The open-circuit terminal voltage is higher than 12V when the battery is not losing power. Use a multimeter to measure the battery voltage. If the voltage is lower than 12V, there has been a broken grid or short circuit inside the battery and cannot be repaired. When measuring the open-circuit voltage of the battery, the battery should be in a stable state. After the battery is charged, discharged or filled with distilled water, it should be allowed to stand for half an hour before measuring. The open circuit voltage of the battery can be measured with the voltage range of a multimeter, and the positive and negative test leads of the multimeter can be connected to the positive and negative electrodes of the battery respectively. The battery terminal voltage can reflect the degree of battery storage, the relationship between them is shown in Table 1 Table 1 The relationship between battery terminal voltage and stored power storage capacity (%) 1007550250 battery voltage (V)> 12.612.412.212 <11.9 even if it has just been discharged Electric batteries, the voltage should also be greater than or equal to 11.6V (5) The batteries that have been repaired with active agents cannot be repaired. Because the battery repair active agents on the market all contain carbon components, the original battery contains impurities, which will cause precipitation over time, so it cannot be repaired. (6) If possible, the internal resistance of the battery can be measured. If the internal resistance of the battery has increased by 100% compared to the new one, the repair should be considered abandoning. 3. Inspection and judgment (1) Check whether there is water shortage: After fully charged, the open circuit voltage is higher because the sulfuric acid concentration is higher than before the water loss; it is difficult to measure the sulfuric acid concentration in the sealed battery, and the battery voltage reaches 13.4V or higher to consider whether there is water loss. Electric vehicle batteries generally used for more than 8 months have varying degrees of water shortage. (2) Judgment of vulcanization The battery can be considered vulcanized if the following conditions occur: 1) The battery capacity is reduced, and the voltage drops by 0.1V, and the discharge power is only 0.5Ah at most; 2) The electrolyte density is lower than the normal value; 3) The charging is started and the charging is completed. When the battery terminal voltage is too high; especially when the battery is charged with a current of less than 0.5A, the voltage rises quickly and quickly reaches a higher level (>14.4V) 4) Bubbles are generated prematurely during charging or when charging starts (Open battery); 5) The electrolyte temperature rises quickly during charging. (3) Judgment of electrode plate softening. If black matter floats up from the battery, the electrode plate is softened and the electrolyte is extracted. If the electrolyte is not very turbid, the battery can continue to be used after repair. If the electrolyte is black, It shows that the plate is seriously softened and the battery is difficult to repair. The sealed battery has no bright liquid. The dark electrolyte can only be seen when the battery is shaken after adding water. When the battery is discharged, the voltage is not lower than the normal value, or even higher. Before the discharge to 12V, almost everything is normal, but at 12V From left to right, it will suddenly drop rapidly, and the inflection point will be greatly advanced. We can think that a serious softening of the plate has occurred. (4) During battery discharge measurement, if the load voltage drops by 0.1V when the battery starts to discharge, the discharge capacity is lower than 0.4C or the load voltage drops rapidly below 11.8V. Generally, the battery capacity should be lower than 40% of the rated capacity. The battery generally has no repair value. 4. Repair process For sealed batteries, a basic repair process includes preliminary selection, information recording, discharge measurement, replenishment of liquid, pulse repair, and measurement judgment. The repair process of using the pulse method to repair the battery is shown in Figure 2. The repair process of using additives Figure 3; The open battery can be repaired by hydrotherapy, and the process is shown in Figure 4. Figure 1 Since the vulcanized plate and the pulse repair effect (magnification 500 times) Figure 2 Pulse method repair flow chart 3 Battery repair process (using additives) Figure 4 Hydrotherapy battery repair process 5. Cautions (1) Discharge detection: to be measured before Fully charge the battery first, and then discharge to the end voltage for capacity detection. The state of the same battery should be consistent every time it is fully charged. (2) Deep discharge: 1) Discharge load: electric furnace wire, bulb, resistance, etc. can be used, and the required current is about 0.2C. 2) Discharge end time: when the battery voltage is less than 3V. At this time, the bulb is reddish or extinguished.