If the main battery pack of lithium ion battery is selected, matched, packaged and installed, it will make a conservative attempt to determine whether the content and differential pressure can pass the test.
The consistency between battery series and parallel units needs special consideration in battery pack. Only with good capacity, state of charge, internal resistance, self discharge consistency, etc., can the capacity of the battery pack be exerted and released. If the consistency is poor, the overall performance of the battery pack will be seriously affected, and even overcharge or over discharge will be caused, resulting in potential safety hazards. A good matching scheme is an effective way to improve the monomer consistency.
Charging mode
Proper charging system has an important effect on the discharge capacity of battery. If the charging depth is shallow, the discharge capacity will be reduced accordingly. If overcharged, it will affect the chemical active substances of the battery, cause irreversible damage, and reduce the capacity and service life of the battery. Therefore, it is necessary to select the appropriate charging rate, upper limit voltage and constant voltage cut-off current to ensure the optimization of charging efficiency and safety and stability while realizing the charging capacity.
Lithium ion batteries are subject to the influence of ambient temperature. Too high or too low temperature will affect the battery capacity. The cycle life of the battery working at high temperature for a long time may be affected, and the capacity is difficult to play if the temperature is too low.
The discharge rate reflects the high current charging and discharging capacity of the battery. The rate is too small and the charging and discharging speed is slow, which affects the test efficiency; If the magnification is too large, the capacity 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.
discharge rate
Discharge rate is a very important index for power battery. The high rate discharge of the battery is a test for the positive and negative materials and electrolyte. For the cathode material lithium iron phosphate, its structure is stable, the strain during charge and discharge is small, and it has the basic conditions for high current discharge, but the disadvantage is the poor conductivity of lithium iron phosphate. The diffusion rate of lithium ions in the electrolyte is the main factor affecting the discharge rate of the battery, and the diffusion of ions in the battery is closely related to the battery structure and electrolyte concentration. The available capacity of the battery decreases with the increase of discharge current.
When lithium-ion batteries discharge at the tip, the national standard 1C is generally adopted, and the maximum tip discharge current is usually controlled at 2 ~ 3C. When a large AC current is used for tip discharge, a large temperature rise will occur and lead to energy consumption. Therefore, it is necessary to monitor and control the temperature of the dry battery pack in time to prevent damage to the dry battery caused by excessive temperature transition and reduce the service life of the dry battery.