"Why I Only Charge My iPhone to 80% Instead of Fully Charging" – Everyone's Got It Wrong; Fully Charging Isn’t Always Best

Sometimes, we don’t drain our iPhone’s battery completely in a day. That’s why the 80% charging feature on the iPhone 15 is a smart way to help preserve battery health. iPhone users are obsessed with battery life, so why stop at 80% instead of charging to 100%? Isn’t a full charge supposed to last longer?

 

 

Adrian Kingsley-Hughes of ZDNet tested the new charging method on the iPhone 15 Pro Max, using it for a long day of activities to see what would happen. Here’s his experience.

Why Only Charge to 80%?

As I’ve observed, no topic generates more articles, blog posts, and YouTube videos than optimizing iPhone battery life. It’s a subject that many users ask about and comment on. Everyone is fixated on squeezing the maximum usage time from each charge.

Every minute of usage and every percentage point of battery counts. Yet, Apple oddly recommends sacrificing one-fifth of the battery’s capacity.

On the iPhone 15, there’s an integrated iOS feature called "80% Limit."

This feature expands on the concept of optimized charging—which used to keep overnight charging capped at 80%, only topping up to 100% about an hour before you typically wake up. The new feature makes 80% charging a permanent limit.

To try this feature on the iPhone 15, go to Settings > Battery > Optimized Battery Charging.

Apple expects this feature to improve the iPhone’s battery lifespan, particularly once you hit 1,000 charge cycles. Most chemical degradation occurs when charging from 80% to 100%.

I was curious about this feature, so over the past few weeks, I experimented to see if I—a person always obsessed with battery life—could manage with 20% less battery capacity. Of course, it’s too early to tell whether this feature will affect battery degradation in the long run, so I’ll have to wait about a year for the full results.

In the meantime, I wondered if a 20% reduction in battery capacity would be a significant issue. It turned out that after a few days of initial worry about battery levels, I stopped noticing or thinking about it.

At first, starting the day with only 80% battery felt extremely odd—like I had already used my iPhone for several hours. However, looking back at my usage habits before this experiment, I realized that I rarely ended a day with less than 35% battery on my iPhone 14 Pro Max. And of course, the iPhone 15 Pro Max even performs better.

For a heavy user like me, an 80% charge is enough for a normal day. So I decided to challenge my iPhone and take the risk.

So, 80% Isn’t That Bad?

I began a hiking trip with my iPhone 15 Pro Max, using it for navigation, taking photos, and recording videos to review products, while also capturing the thick mud I encountered along the way. I decided not to bring a power bank because I considered that “cheating.”

I planned for the hike and product review to take about eight hours, during which my iPhone would be heavily used. The challenge was compounded by cold and damp weather—conditions known to drain battery life faster.

Everything went fine. I started my hike with 80% battery and returned to the car with 48%, along with countless videos and photos. I took plenty of pictures and still had a lot of battery left at the end of the day.

I developed two strategies to make the transition to a “lower” battery level go smoothly.

The first was to be resourceful all the time. I found that brief charging sessions work very well. Just spending a few minutes on a charging dock, car charger, portable power bank, or wall charger can make a significant difference. In these cases, the charging process only takes a few minutes.

Another effective strategy was psychological. I turned off the battery percentage display on my iPhone. Instead of focusing on each percentage point dropping, I now concentrate on the overall picture.

If you currently have the battery percentage display on and want to turn it off, go to Settings > Battery and then disable Battery Percentage.

The Bottom Line: The iPhone 15 Pro Max has enough energy to keep me going all day, even when the battery isn’t at full capacity.

If I’m traveling or need maximum battery life, I’ll bring a power bank or disable the 80% limit. But on most normal days, the 80% limit is truly sufficient.