Compared with traditional battery technology, lithium-ion batteries charge faster, last longer and have a higher power density for more battery life in a lighter package. When you know a little about how they work, they can work that much better for you.
It charges fast for convenience and slow for longevity.
Your Apple lithium-ion battery uses fast charging to quickly reach 80 per cent of its capacity, then switches to slower trickle charging. The amount of time it takes to reach that first 80 per cent will vary depending on your settings and which device you’re charging. Software may limit charging above 80 per cent when the recommended battery temperatures are exceeded. This combined process not only lets you get out and about sooner, it also extends the lifespan of your battery.