Which setting is more effective for battery longevity on iPhone?

My opinion......the 80% Limit is a gimmick that was designed to answer the "noise" on the Internet from users who think that their battery will explode if it is charged to 100%.

You may not be aware that even if you decide to use the 80% Limit, the battery will still charge to 100% "on occasion" according to Apple. "On occasion" seems to be anywhere between 1-3 times a month on average.

In theory......the 80% Limit.....if it really was an 80% limit......might result in a few more months of use for the battery over the years. But, you have to charge the battery more often with an 80% Limit, a fact that most users don't think about....and, as I already mentioned, the battery is still going to charge to 100% "on occasion", whatever that might be.

Personally, I set the phones here for Optimized Battery Charging and ignore the 80% Limit. I connect the phones to the power adapter at night and leave them connected all night.....every night. The phones charge to 80% fairly quickly and then very slowly trickle charge over the next 4-5 hours.

So, the phones start each day at 100%. I get 2+ more hours of use during the day than I did when I tried the 80% Limit.

If the phones get a month or two less use over the long haul using the 100% method, I could care less. But, some users want to squeeze another month or two out of their batteries. They should probably use the 80% setting and then worry about why the phone is still charging to 100% more often than they would like.

After all, if an 80% Limit is desirable, would not a 70% setting be even better? Watch for more gimmicks like this on newer iOS version releases.

Honestly, I don't believe one is appreciably better than the other. I prefer to have my iPhone charged to 100% in the morning when I awaken, so I use Optimized Battery Charging not the charge limit to 80%. Battery health will decline either way as that's what batteries do. With every full cycle charge, the health of the battery will dip a little. On average, you can expect about a 1% drop in battery health per month. It's not linear, meaning it may remain steady for a while, then dip a point or more all at once. When the health dips to 80%, which will happen one day, if you own your phone long enough, it will then be time to pay Apple to replace the battery.

Things you should do:

• Don't let the battery go below 20% and never fully discharge it to 0%
• Do plug your phone in to charge when you go to bed at night and leave it plugged in to charge, with either of optimized charging options enabled all night EVERY night
• Don't obsess over battery health. It's going to decline no matter what you do