Voltage protection: overcharge and overdischarge, which vary depending on the battery material. It may seem simple, but it takes experience and knowledge to look at the details. Overcharge protection, in our past, the protection voltage of single cell battery was 50~150mV higher than the full voltage of the battery. But electric batteries are different. If you want to extend battery life, your protection voltage should be the battery's full charge voltage, or even lower than this voltage. For example, for lithium manganese batteries, you can choose 4.18V~4.2V. Because it has multiple strings, the life capacity of the whole battery is mainly based on the battery with the lowest capacity. Small capacity batteries always operate at high current and voltage, so the atattenuation is accelerated. For large capacities, charge and discharge gently each time, and natural degradation will be much slower. In order to allow small capacity batteries to be charged and discharged smoothly, the overcharge protection voltage point should not be selected too high. This protection delay can go up to 1S to avoid the impact of pulses and thus protect. Protection against overdischarge is also related to the material of the battery. For example, lithium manganese batteries are generally selected between 2.8V and 3.0V.
Try to be slightly higher than the excessive discharge voltage of a single battery. Because for domestically produced batteries, when the battery voltage is lower than 3.3V, the discharge characteristics of each battery are completely different. Therefore, the battery is protected in advance, which constitutesgood protection for battery life. The overall goal is to try to make each battery run as lightly as possible, which will certainly improve its lifespan. The overdischarge protection time varies depending on the load. For example, for power tools, the starting current is generally above 10°C, so the battery voltage will be pulled to the point of excessive discharge voltage in a short time. Protect. There is no way to operate the battery at the moment. This is something worth noting. Current protection: This is mainly reflected in the fact that the operating current and overcurrent cause the MOS switch to be disconnected to protect the battery or load.