Some views of lithium battery balance, lithium battery balance considerations

　　Author ：Iflowpower – Portable Power Station Supplier

Some views of lithium ion battery balance, lithium ion battery balance considerations. One of the most important part of the lithium-ion battery pack in the process of stamping is equalization, and the lithium-ion battery requires charging overvoltage, discharge under voltage, overcurrent, and short circuit protection. Because you have to ensure that the output of the lithium-ion battery is reasonable to each battery, the most common equilibrium mode of the lithium-ion battery is the energy consumption equalization and the transfers.

Some point of view of lithium ion battery balance in order to supply a sufficient voltage to the device, the lithium ion battery pack is usually connected in series by a plurality of batteries, but the capacity mismatch between the lithium ion battery will affect the capacity of the entire battery pack. To this end, we have to balance the mismatch lithium-ion battery. 1, the lithium-ion battery capacity error is absolute, with the use of lithium ion batteries, this error is expanded.

Factory distribution can only delay the time of obvious error of lithium ion batteries, and ultimately there is a serious capacity error. Therefore, the error is absolute, and the purpose of making a lithium-ion battery protection system and equalization system is also just alleviating this error and preventing the risk of errors. By balancing is impossible, should not be pursued as a balanced goal.

2, the current method of capacity compensation is to remove some of the capacity of lithium-ion batteries to some power to compensate for low capacity battery consumption. This method is theoretically no problem, it is actually very troublesome, especially if efficient is high. 3, the charging voltage equalization is necessary, otherwise the lithium ion battery will appear in the back of the charging.

Some lithium-ion batteries are overcharged, and the life of the battery is recurring, which will lead to danger. 4, doing discharge equalization is not as bad as an undervoltage protection, making an undervoltage of any single lithium-ion battery to conduct power-on protection, preventing the risk caused by over-discharge. Lithium ion battery balanced precautions take longer during the discharge period.

Since the discharge speed is related to the load resistance resistance value, the balance efficiency is low in the system. If balanced during discharge, it is desired to be shorter than the equalization time, then an external power transistor having a smaller on-resistance, such transistors are very common, such as MOSFET or FET. If you want to quickly balance during discharge, the low resistance resistance must be connected in series to reduce the power consumption of the power transistor.

If there is no such a current limiting resistor, the transistor will quickly consume lithium ion battery power. Measuring the lithium ion battery voltage during charging is not accurate, and will cause premature lithium ion battery balanced. Therefore, the charging must be stopped periodically to measure the battery voltage.

The equalization of an external power transistor having a low-conductive resistance is also taken to achieve the battery equilibrium during charging. Balance Management Process Design is very important in any of the lithium-ion battery systems, and now balanced management, whether it is the electric forklift lithium-ion battery system or the new energy vehicle lithium-ion battery system is inseparable from balance management, battery pack internal equilibrium management Among them, whether it is a traditional lead-acid battery, or now the lithium-ion battery, the performance of the performance is not the performance of a single battery, but more dependent on the equalization management performance of the overall lithium-ion battery pack. Summary: Lithium-ion battery equilibrium management technology is one of the key technologies of lithium-ion battery power management, and has important practical and economic significance for research energy issues.

The balance of lithium-ion batteries can't get a good improvement in the current, this technology needs to be improved.