The charging time for your BMW electric vehicle is typically listed as 0-80% state of charge (SOC) because of the charging curve characteristics of lithium-ion batteries used in electric vehicles.
The charging curve for lithium-ion batteries can be divided into two main phases:
Phase 1 (10-80% SOC):
- In this phase, the charger supplies a constant current to the battery, allowing it to charge quickly and efficiently.
- The battery can be charged from 10% to 80% SOC relatively quickly during this phase.
- The charging rate is the highest during this stage, allowing for a rapid increase in the battery's state of charge.
Phase 2 (80-100% SOC):
- As the battery approaches 80% SOC, the charging process transitions to a constant voltage phase.
- In this phase, the charger maintains a constant voltage while the current gradually decreases to prevent overcharging and potential damage to the battery.
- The charging rate slows down significantly during this stage, as the battery requires more time to reach the full 100% SOC.
The reason the charging time is typically listed as 0-80% SOC is that this represents the most efficient and practical charging range for daily use. Charging from 80% to 100% SOC takes significantly longer, and the additional charge gained is relatively small compared to the time required.
By focusing on the 0-80% SOC range, the charging time provided gives a more accurate representation of the typical charging experience for most daily driving needs. This information helps users better understand the expected charging times and plan their charging accordingly.
Learn more about BMW Charging here.
