What do you know about the analysis of lithium-ion battery pack equilibrium charging method?

　　Author ：Iflowpower – Portable Power Station Supplier

Today, today, various high-tech emerges in our lives, bringing convenience for our lives, then do you understand these high-tech might contain charging balance? Lithium ion battery is recently In the market, due to its great improvement, its market share has risen very quickly. The energy storage capacity of the lithium-ion battery is very amazing, even so, the capacity of a single battery unit is still too low from the voltage or from the current, and cannot meet a hybrid engine. Parallel and plurality of battery cells can increase the current supplied by the battery, and a plurality of battery cells can increase the voltage supplied by the battery.

Charge balance (abbreviation is equal charge) is a charge that balances battery characteristics. It refers to the imbalance of battery terminal voltage due to individual differences and temperature differences due to battery during the battery. In order to prevent this imbalance trend, the charging voltage of the battery pack must be added and the battery is activated and charge it to balance the characteristics of each battery in the lithium-ion battery group and extend the battery life.

. If the voltage exceeds the allowable range, the lithium ion battery is easily damaged. If the voltage exceeds the upper and lower limit (as an example of the nanophosphate ion battery, the lower limit voltage is 2V, the upper limit voltage is 3.

6V), may damage the battery. The result is at least speeding up the self-discharge speed of the battery. The battery output voltage is stable within a wide range of charge (SOC), and the risk of voltage deviation is small.

However, on both ends of the security range, the ups and ducts of the charging curve are steep. Therefore, as a preventive measures, the voltage must be strictly monitored. Common balanced charging technologies include constant parallel resistance equalization charging, open-related resistance equalization, average battery voltage equalization charging, switching capacitor equilibrium charging, step-down converter equalization charging, inductance equalization charging, etc.

The ion battery should be connected in series, each battery should be charged, otherwise it will affect the performance and life of the whole set of batteries during use. The existing single-cell lithium-ion battery protective chip does not have a balanced charging control function, to connect multiple lithium ion battery protection chip equalization charging control functions to CPU. Implemented by serial communication with protective chips and expands protection circuit.

The complexity and difficulty of design reduces the efficiency and reliability of the system, and adds power consumption. Traditional passive method: In a general battery management system, each battery unit is connected to the load resistance through the switch. This passive circuit can discharge the selected single unit.

However, this method is only applicable to the voltage rise of the most solid battery cell in suppressing charging mode. To limit power consumption, this type of circuit usually allows only a small current discharge of about 100 mA, causing charge balancing possibly up to several hours. When the production of the lithium-ion battery pack is longer, since the static power consumption of each of the protective plates is different and the self-discharge rate of each of the batteries is different, the voltage of each string battery is inconsistent.

Balanced the function of balancing the voltage of the lithium ion battery pack, so that the capacity of the battery pack capacity can achieve the maximum efficiency of the battery pack. Active balance method: There are many active balance methods in related materials, all of which have a storage element for energy transfer. If the capacitor is used as a storage element, the capacitor is connected to all battery cells to have a huge switch array.

A more effective way is to store energy in a magnetic field. Key components in the circuit are transformers. The circuit prototype is developed by the Development Team of Infertile and VogtelectronicComponentsGmbH.

The parallel gear circuit is added to each single battery of the lithium ion battery group to achieve the purpose of delivering. In this mode, when the battery is first fully charged, the equalization device can prevent it from overcharge and convert excess energy to heat, and continue to charge battery insufficient battery. This method is simple, but it will cause energy loss, not suitable for fast charging system.

Before charging, each battery is discharged to the same level by the same load, and then performs constant current charging to ensure that the balance between the batteries is more accurate. However, regarding battery packs, due to physical differences between individuals, it is difficult to achieve exact consistent ideal effect after depth of each battery unit. Even if the same effect is reached after discharge, new imbalance occurs during charging.

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