The Lifespan of Rechargeable Batteries — Those 'Degradation Secrets' You’ve Been Ignoring

Many people have had such an experience: after using a mobile phone for one or two years, the battery becomes more and more durable, and a full charge can only last for most of the day; after using an electric vehicle battery for three or four years, the cruising range is greatly reduced. This is actually the "loss" phenomenon of rechargeable batteries—all rechargeable batteries have a certain service life, and with the increase of usage times, the capacity will gradually decrease, and finally can not meet the usage needs.

The service life of a rechargeable battery is usually measured by "cycle times", which refers to the complete process of discharging the battery from a fully charged state to the cut-off voltage and then fully charging it. Different types of batteries have great differences in cycle life: the cycle life of lithium batteries is usually 500-1500 times, nickel-metal hydride batteries 300-1000 times, and lead-acid batteries 300-500 times. It should be noted that the number of cycles is not "one charge counts as one time". For example, if a mobile phone is discharged from 100% to 50% and then fully charged, it only counts as 0.5 cycles.

In addition to the number of cycles, many factors will accelerate battery loss: first, charging temperature. Too high or too low temperature will damage the battery. The optimal charging temperature is 20-30℃, avoiding charging in high temperature exposure or low temperature environment; second, charging habits. Overcharging (remaining plugged in for a long time after being fully charged) and over-discharging (using until the power is exhausted and automatically shutting down) will seriously damage the battery; third, storage method. When storing for a long time, it is most appropriate to keep the battery power at 40%-60%, avoid storing it fully charged or without power, and keep it in a cool and dry place.

Understanding these "loss codes" and developing good usage habits can effectively extend the service life of rechargeable batteries, reducing resource waste and usage costs.