1. Battery Life: Charging a battery to 100% can have somewhat negative consequences for the battery's lifespan. It is known that constantly charging to 100% and keeping a fully charged battery for extended periods can accelerate battery degradation. Charging the battery only up to 80% reduces this potential degradation effect and can extend the battery's lifespan.
   
   

2. Fast Charging Capability: Charging a battery from 80% to 100% can take significantly longer than charging the battery from 0% to 80%. This is because most charging stations, especially fast chargers, slow down the charge rate as the battery approaches 100%. The majority of the charging time is spent achieving an 80% full charge, while charging from 80% to 100% proceeds much slower. Therefore, it may be more efficient to charge up to 80% and then drive off instead of waiting for the battery to be fully charged.
   
   

3. Driving Range: In most daily driving conditions, a range of 80% is sufficient to meet the needs of most people. Most electric cars have a reasonable range, and charging up to 80% generally provides enough miles for daily use. Therefore, it is not always necessary to fully charge the battery unless you plan to cover long distances.

However, it is important to note that occasionally fully charging the battery to 100% can be beneficial, for example, for longer trips where you want to utilize the car's full range. Regularly charging to 80% and occasionally to 100% can offer a good balance between maximizing battery life and meeting your range needs.