iPhone 80% Charging Limit
With the iPhone 15 models that came out last year, Apple added an opt-in battery setting that limits maximum charge to 80 percent. The idea is that never charging the iPhone above 80 percent will increase battery longevity, so I kept my iPhone at that 80 percent limit from September 2023 to now, with no cheating.
My iPhone 15 Pro Max battery level is currently at 94 percent with 299 cycles. For a lot of 2024, my battery level stayed above 97 percent, but it started dropping more rapidly over the last couple of months.
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I don’t have a lot of data points for comparison, but it does seem that limiting the charge to 80 percent kept my maximum battery capacity higher than what my co-workers are seeing, but there isn’t a major difference. I have four percent more battery at 28 more cycles, and I’m not sure suffering through an 80 percent battery limit for 12 months was ultimately worth it.
It’s possible that the real gains from an 80 percent limit will come in two or three years rather than a single year, and I’ll keep it limited to 80 percent to see the longer term impact.
I’m so glad Clover ran this test for a year and reported her results, because it backs up my assumption: for most people there’s no practical point to limiting your iPhone’s charging capacity. All you’re doing is preventing yourself from ever enjoying a 100-percent-capacity battery. Let the device manage its own battery. Apple has put a lot of engineering into making that really smart.
My iPhone 15 Pro, now just under a year old, shows a maximum capacity of 91% and a cycle count of 145. I have been using the automatic optimized charging, mostly via MagSafe. The cycle count is low so I expected better. I certainly notice the phone depleting more than when it was new
I think there are two conclusions here. First, the benefit of the 80% limit is not very clear, although presumably Apple had reason to believe it would help in some circumstances. Second, batteries still don’t last very long, even with the fancy optimized charging. It still seems like the health will be almost down to 80% after two years. I wish battery replacements were easier or that Apple started out with larger batteries for more headroom.
[The] iPhone 15 is the first one that’s rated for 1000 cycles, not 500 like previous models. I would expect battery health to be over 90% after a year; if it’s not, I see it hard for it to last 1000 cycles and still charge to 80%.
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[The] real story is that these phones won’t last 1000 cycles. I don’t think most of the people in the comments realize that the iPhone 15 is supposed to last twice as long as previous iPhones.
My 2 1/2-year-old Apple Watch SE is down to 76% battery health. Apple recommends that I service it, but I’m not sure it’s worth $99 for a new battery when there will probably be a new SE soon. What’s strange is that the watch usually easily lasts through the day, but sometimes it will run out of power around 5 PM for no apparent reason. The Settings app shows that it was fully charged in the morning and then steadily declined, even though I wasn’t really even using it. Unlike on iOS, there doesn’t seem to be a way to display the power drain by app.
See also:
Previously:
- Products’ Useful Lifespans Should Be Longer Than Their Batteries
- Turning a Basic Task Into a Complicated Nightmare
- Mysterious Reduced iPhone Battery Life
- Apple’s Message to Customers About iPhone Batteries and Performance
- Apple Confirms That It Throttles iPhones With Degraded Batteries
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One more data point: My iPhone 15 Pro shows 100% capacity (yes, one hundred percent) and 134 cycles after the first year. I have been keeping it below 80% almost all of the time, only charging it all the way up on the few days when I expected (usually wrongly) that I would need more oomph to get through the day. And I don't do wireless charging at all.
I just checked mine and it's at 98% after 227 cycles.
A few weeks ago, before I started running 18 and 18.1 betas, it was still at 100% health. I think the charge limit works great, what probably degraded my battery is the impact of discharging it below 20% too often since I started using the betas.
This argument that Apple made it "really smart" is hard to sell. My Apple Watch Ultra 2 has optimized charging enable, but rarely limit the charge to 80%, despite my daily routine of using only about 40% of the battery and recharging it.
For me personally, 80% charge is more than ample for a typical day (not for a travel day), and 100% charge does not extend the life enough to significantly improve convenience. Now if it were the difference between, say, 6 days and a full week, that would be valuable enough for me despite the relatively small percentage difference. (I'm not about to give up the full smartphone capabilities but I do miss the whole-week battery life of the old Nokias.)
My iPhone XS is at 77%. Optimized charging is on. And I have it on a charging stand all day long now that I've been working from home since March 2020.
