What is the impact of discharge rate on powerwall lithium battery? Before answering this question, we need to know the composition and structure of the powerwall lithium battery? For example, the 48v powerwall lithium battery is composed of a lithium battery pack. What is a lithium battery pack? The lithium battery pack mainly refers to the process of assembling lithium battery cells into groups, which is called PACK. It can be a single battery or a series parallel battery module. Lithium battery pack includes battery pack, bus bar, soft connection, protective plate, outer package, output (including connector), highland barley paper, plastic bracket and other auxiliary materials to form a lithium battery pack.
48v lithium battery pack mainly tests the electrical performance of the battery cell after screening, assembly, packaging and assembly to determine whether the capacity and differential pressure are qualified products. The discharge rate reflects the battery's large current charge and discharge capacity. The rate is too small and the charge and discharge speed is slow, which affects the test efficiency; If the magnification is too large, the capacity of the battery will be reduced due to the polarization effect and thermal effect of the battery. Therefore, it is necessary to select an appropriate charge discharge magnification.
The proper charging system has an important influence on the discharge capacity of the battery. If the charging depth is shallow, the discharge capacity will be reduced accordingly. If the wall mounted energy storage battery is overcharged, it will affect the chemical active substances of the battery and cause irreversible damage, reducing the capacity and life of the battery. Therefore, it is necessary to select appropriate charging rate, upper limit voltage and constant voltage cut-off current to ensure optimal charging efficiency and safety and stability under the condition of achieving charging capacity. At present, power lithium ion batteries mostly use constant current constant voltage charging mode. By analyzing the constant current and constant voltage charging results of lithium iron phosphate battery system and ternary system batteries under different charging currents and different cut-off voltages, it can be seen that: (1) when the charging cut-off voltage is constant, the charging current increases, the constant current ratio decreases, the charging time shortens, but the energy consumption increases; (2) When the charging current is fixed, the constant current charging ratio decreases with the decrease of the charging cut-off voltage, and the charging capacity and energy are decreasing. To ensure the battery capacity, the charging cut-off voltage of lithium iron phosphate battery shall not be lower than 3.4V. It is necessary to balance the charging time and energy loss, and select the appropriate charging current and cut-off time