1. Battery Life: Charging a battery to 100% can have somewhat negative consequences for the battery's lifespan. It's 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, reduce the charging speed as the battery gets closer to 100%. Most of the charging time is spent reaching an 80% full charge, while charging from 80% to 100% is much slower. Therefore, it can be more efficient to charge up to 80% and drive on, rather than waiting for the battery to be fully charged.
   
   

3. 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 to 80% typically provides enough miles for daily use. Therefore, it is not always necessary to fully charge the battery unless you plan to travel long distances.

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