Dongjin Group
Design and Realization of Improving the Safety of Battery Charging System-Parallel Lithium Battery

Design and Realization of Improving the Safety of Battery Charging System-Parallel Lithium Battery

Many types of adapters can be used to charge lithium-ion batteries and power the system, and the electrical specifications of each rechargeable lithium battery are usually different. This requires system designers to build portable devices, which meet the safety and reliability requirements when using different adapters. Enhance robust security performance. Dongjin fully integrates input overvoltage, input overcurrent, battery overvoltage and reverse input polarity protection, which can significantly improve the safety of battery power supply system.

The ultimate purpose of parallel lithium battery of rechargeable lithium batteries is to increase capacity. Therefore, parallel lithium battery has some different characteristics in design compared with single lithium batteries, mainly reflected in the consistency of charging current design and parallel batteries.

Generally speaking, the characteristics of parallel lithium batteries are as follows: the voltage is constant, the capacity of batteries is added together, the internal resistance is reduced, and the power supply time is prolonged. The core content of parallel charging is the magnitude and function of parallel current. According to the theory of parallel connection, the trunk current equals the sum of all branch currents. Therefore, in order to achieve the same charging efficiency as a single lithium battery, the charging current should be the sum of the current of N lithium batteries.

Under the formula of I = U / R, this design is reasonable. However, the internal resistance of parallel batteries will also change. According to the formula of parallel internal resistance, the total internal resistance of two parallel lithium batteries is equal to the ratio of the product of internal resistance of two batteries to the sum of their internal resistance, and the parallel resistance will decrease with the increase of the number of parallel batteries. Therefore, the efficiency of parallel charging of lithium batteries can be realized on the basis that the current of lithium batteries in parallel is less than the sum of the current of N lithium batteries in parallel.

Generally, after parallel connection of lithium batteries, there will be a charge protection chip to protect the lithium batteries. As one of the excellent manufacturers of rechargeable lithium batteries, battery of Dongjin has fully considered the changes of lithium batteries after parallel connection, and also designed the current and selected the batteries according to the above requirements. Therefore, users need to charge lithium batteries on time according to the instructions of parallel lithium batteries, so as to avoid possible damage to batteries caused by incorrect charging methods.