We define "Fast Charging" as charging a battery faster than the device manufacturer's stock chargers do. This means we identify the the max charge rate of the battery itself. We do this by identifying the battery configuration and the cell type of the battery. The battery information alongside the cell manufacture cell data sheet tell us what the max charge rate of the battery can be. We also consider factors such as wire gauge and the rated current of the connector.
This means two things:
- Less charging time
- Slightly more degradation on your battery, as fast charging puts some stress on the battery quicker than slow charging but not any more than the cell manufacture intended
The second reason is why we recommend only fast charging when you need to.