The life of 12v ternary lithium batteries is calculated by the ratio of capacity attenuation degree after a certain degree of use, and terminates directly until the capacity life is zero. The industry algorithm is generally three yuan lithium battery after full discharge once, this is called cycle life. Irreversible chemical reactions within lithium batteries can result in a reduction in battery capacity, such as improper use, or extremely high or very low temperature use. For example, the decomposition of electrolyte, the inactivation of active materials, the collapse of positive and negative structures lead to the reduction of lithium ion embedding and de-embedding. Experiments show that higher discharge rate will lead to faster capacity decay. If the discharge current is low, the battery voltage will approach the equilibrium voltage, which can release more energy.
The theoretical life of 12v ternary lithium batteries is 1200 times full charge and discharge, that is, full cycle life. According to the frequency of use, three days full charge and discharge, 120 times a year full charge and discharge, the service life of 12v ternary lithium batteries reaches 10 years, even if there is loss in the process of use or the number of days of charge and discharge decreases, it can reach eight years. Meaning, what we are talking about here is the capacity life. After eight years, the capacity of 12v ternary lithium batteries will be more than 60%, which is the standard.
The theoretical life of the three element lithium battery is moderate in commercial rechargeable lithium batteries. Lithium iron phosphate is about 2000 times, and lithium titanate is said to achieve 10 thousand cycles. At present, the mainstream battery manufacturers promise more than 500 times in the specifications of 12v ternary batteries (charging and discharging under standard conditions). But after the batteries are packed into batteries, the cycle life of the batteries is about 400 times due to the consistency problem, mainly because the voltage and internal resistance can not be exactly the same. The manufacturer recommends that SOC use window be 10%~90%. Deep charge and discharge is not recommended. Otherwise, it will cause irreversible damage to the structure of positive and negative electrodes of batteries. If calculated by shallow charge and shallow discharge, the cycle life will be at least 1000 times. In addition, if lithium batteries are discharged regularly at high power and high temperature, the battery life will drop dramatically to less than 200 times.