The frequency of charging significantly affects the lifespan of lithium-ion batteries, and managing how often and how fully you charge these batteries is key to maximizing their usable life.
Impact of Charging Frequency on Lifespan
- Charge Cycles and Lifespan:
Lithium-ion batteries typically last for about 300 to 500 full charge-discharge cycles or around 2 to 3 years, whichever comes first. A “charge cycle” is defined as using 100% of the battery’s capacity, which can be spread over multiple partial charges. - Partial vs. Full Cycles:
Shallow or partial charging (using only a fraction of the battery before recharging) can greatly increase the total number of charge cycles. For example, using only half the battery capacity before recharging can allow 600-1000 charge cycles, and using about one-eighth capacity can extend it to 2400-4000 partial charge cycles. This means frequent shallow charging is less stressful and extends battery life compared to frequent deep discharging. - Avoiding Full Discharges:
Regular full discharges (draining the battery to near 0%) are harmful and reduce lifespan. It’s generally recommended to recharge lithium-ion batteries when they drop to around 20-30% capacity rather than waiting until fully depleted. - Optimal Charge Window:
Maintaining the battery charge between about 20% and 80% is considered optimal to reduce stress and degradation, thus prolonging lifespan. - Overcharging and Heat:
Leaving lithium-ion batteries plugged in after reaching 100% charge can cause heat buildup and accelerate degradation, so it’s advised to unplug once fully charged.
Special Considerations for Electric Vehicles (EVs)
- Charging an EV lithium-ion battery occasionally to 100% is beneficial for recalibrating the battery management system (BMS) and maintaining accurate state-of-charge readings. However, frequent charging to full capacity can increase stress on the battery and reduce lifespan, so it should be limited to when maximum range is needed.
Summary
| Charging Practice | Effect on Lifespan |
|---|---|
| Frequent shallow charging (20-80%) | Extends lifespan by reducing battery stress |
| Full discharges (0% level) | Reduces battery lifespan significantly |
| Regular full charges to 100% | OK occasionally for recalibration, but frequent use stresses battery |
| Leaving plugged in after 100% | Causes heat buildup and accelerates degradation |
In essence, lithium-ion batteries last longest when charged regularly before deep discharge, kept within moderate charge levels, and not left plugged in after full charge. Charging frequency combined with charge depth management is the most critical factor in extending battery life.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-charging-frequency-affect-the-lifespan-of-lithium-ion-batteries/
