iPhone XR: optimizing battery health

See my user tip—>When to charge your iPhone or iPad - Apple Community

There are marginal benefits for doing extreme procedures to try and extend battery longevity. Even Apple’s optimized battery charging is of limited benefit since it still charges to 100%, but only at a later time.

y_p_w wrote:

There are marginal benefits for doing extreme procedures to try and extend battery longevity. Even Apple’s optimized battery charging is of limited benefit since it still charges to 100%, but only at a later time.

I’m not convinced there are even marginal benefits. Any benefit by not charging to 100% is offset by the fact that when the battery is left connected at 100% energy to run the phone comes from the mains rather than the battery, allowing the battery to “rest”, but even more important it reduces the number of charge/discharge cycles. If you disconnect at, say 80% all energy to run the phone comes from the battery, which must be eventually replaced, meaning another partial discharge/charge cycle.

I know that people cite the instructions for Teslas, which say to only charge to 100% before a long trip, but to keep it below 80% otherwise. But there is a HUGE difference between an electric car and a smartphone: You never drive a Tesla while it is plugged in (picture the extension cord that would be needed!), but your phone is using energy all the time when plugged. While Apple’s new optimized charging does go to 100%, it is designed so that it reaches 100% just in time for heavier use, which will bring the charge level down pretty quickly.

Lawrence Finch wrote:

y_p_w wrote:

There are marginal benefits for doing extreme procedures to try and extend battery longevity. Even Apple’s optimized battery charging is of limited benefit since it still charges to 100%, but only at a later time.

I’m not convinced there are even marginal benefits. Any benefit by not charging to 100% is offset by the fact that when the battery is left connected at 100% energy to run the phone comes from the mains rather than the battery, allowing the battery to “rest”, but even more important it reduces the number of charge/discharge cycles. If you disconnect at, say 80% all energy to run the phone comes from the battery, which must be eventually replaced, meaning another partial discharge/charge cycle.

I know that people cite the instructions for Teslas, which say to only charge to 100% before a long trip, but to keep it below 80% otherwise. But there is a HUGE difference between an electric car and a smartphone: You never drive a Tesla while it is plugged in (picture the extension cord that would be needed!), but your phone is using energy all the time when plugged. While Apple’s new optimized charging does go to 100%, it is designed so that it reaches 100% just in time for heavier use, which will bring the charge level down pretty quickly.

There is truth to limiting the charge range in order to extend longevity. However, Apple doesn't have any automated settings to do that, and doing it manually isn't practical. I suspect that iPads and Mac notebooks are rated for 1000 charge cycles (in part) because the batteries are bigger where they set 0-100% a bit closer to the middle of the range.

But absolutely one could delay having to replace the battery by simply using a power source. Some still using charging cases. I seem to recall Amtrak conductors were using the iPhone 4s for a long time using a combination battery case and code reader. Wasn't it rated for 300 charge cycles to 80%?

I still can't figure out the point of optimized charging. A way to program/reduce the charge range would do more to extend battery life than that.

Leave it on a charger as long as you like. You can't overcharge it.