Through a combination of bigger batteries and greater efficiency, Apple has drastically improved iPhone battery life over the years.

There’s a common saying among many tech experts that the iPhone’s ideal battery charging zone is between 30 and 80 percent. We’re often reminded not to charge our phones all the way to 100 percent and to avoiding letting it dip down to 0 percent

German sister site Macwelt asked Facebook users to share screengrabs to show their battery health and to determine whether they charged to 80% or 100%. Data was only collected from iPhone 15 users to ensure there was a year’s worth of usage.