A saying widely circulated in the industry is: The battery is not worn out, it is badly charged. In order to meet the short-term high-capacity charging of electric bicycle batteries, in the three-stage constant-voltage current-limiting charging, the constant voltage value has to be increased to 2.47V～2.49V. In this way, it greatly exceeds the oxygen evolution voltage of the positive plate of the battery and the hydrogen evolution voltage of the negative plate. In order to reduce the charging time indication, the products of some charger manufacturers increase the current from constant voltage to float charging. After the charging indication is fully charged, it is not fully charged yet, so it can be compensated by increasing the float voltage. In this way, the floating charge voltage of many chargers exceeds the single cell voltage of 2.35V, so that a large amount of oxygen is still evolved during the floating charge stage.
The oxygen cycle of the battery is not good, so it is constantly exhausted during the floating charge stage. The constant voltage value is high and the charging time is guaranteed, but the sacrifice is water loss and vulcanization. The constant voltage value is low, and the charging time and the charged power are difficult to guarantee. On the basis of improving the battery grid alloy of the battery, increasing the gas evolution potential, improving the oxygen cycle performance, and improving the efficiency of the sealing reaction, the maximum charging voltage is controlled to be below 2.42V, that is, below the hydrogen evolution potential. This will inevitably lead to an extension of the charging time, which must be in the state of high-current charging (current-limiting charging), adding a depolarized negative pulse to improve the battery's charge acceptance ability, and charging more when charging with high current Some power to shorten the charging time. 70% of the 2C current charging is when the battery has a relatively large charge acceptance capacity, the battery is charged with a high current, and the damage to the battery is relatively small. The battery is basically not higher than the serious hydrogen evolution voltage.
Once the voltage is higher than the hydrogen evolution voltage, the battery will quickly lose water. To use this type of charger, continuous charging and discharging must be used. If the charging is stopped for a few days in the middle, the battery will cause serious vulcanization and premature failure. The user cannot guarantee that the battery can be charged in time after each use. If the battery is not charged in time for several times within a year, the vulcanization of the battery will accumulate. Most charger manufacturers say that car manufacturers do not accept chargers that can guarantee battery life due to price factors. It should be admitted that this is the case for most small companies, but large-scale and developed companies can indeed not buy good chargers at high prices. Some charger manufacturers exaggerate certain functions, and the effect of the finished product is not as good as its advertised. There are many functions that belong to the concept of selling, and the actual effect is limited.