iPhone 6(S)/Plus Battery Capacity - Accurate?

[polyphenol]

My 6s, now obviously somewhat old (it was bought shortly after release), is has poor battery life. Not a big surprise. Nowadays, I never get a full day out of it - and most of the time I am not a heavy user, and it is mostly on a good wifi rather than 3G/4G.

What I can't get my head round is that the battery is shown to have 83% Maximum Capacity. And has had this for many months. Yet my perception is that it has got very significantly worse over the same time. In particular, it now drops like a stone at times. And, on connecting to power, rises almost as ridiculously fast. Behaviour I have seen on other earlier models of iPhone - and always meaning battery is on the way out.

I simply do not believe 83%. If at one time it was true, it is no longer.

Does anyone actually believe this capacity analysis?

 

[JPack]

It's a rough estimate of the capacity. The battery is designed for 500 charge cycles, so if you're doing a full charge per day, the battery should be replaced every 18 months. If you purchased the iPhone in 2015, it's far overdue for battery service.

 

[now i see it]

The % number displayed as battery maximum capacity doesn't equate to anything in the real world except to notify the user that the battery is worn out. It's not like you can expect 17% less run time on a 83% capacity battery. By the time it gets to that level, rapid discharge, unexpected shutdowns in cold weather and erratic charging behavior can be expected

 

[polyphenol]

It's a rough estimate of the capacity. The battery is designed for 500 charge cycles, so if you're doing a full charge per day, the battery should be replaced every 18 months. If you purchased the iPhone in 2015, it's far overdue for battery service.

Well aware that it is overdue! But the cost and/or disruption of a battery service is ludicrous.

The nearest physical location is almost 90 miles away so 4-5 gallons of petrol. Somewhere we really hardly ever have good reason to travel to. And in a Covid-19 restricted area.

Current remote replacement is estimated at 6-10 days. Which is a long time without my phone in these days of one-time codes for everything under the sun. No - I don't have a second phone, not since I traded in my Galaxy S2 a few months ago.

Anyway, I was really asking to know if in the future I can expect accuracy? For example, if I buy a 12 and it arrives with 100%, can I expect an accurate trace of battery deterioration? Or something more akin to the random number that now appears? If not accurate, could I take it that staying at, say, 90% means little further deterioration? Or not?

 

[JPack]

Anyway, I was really asking to know if in the future I can expect accuracy? For example, if I buy a 12 and it arrives with 100%, can I expect an accurate trace of battery deterioration? Or something more akin to the random number that now appears? If not accurate, could I take it that staying at, say, 90% means little further deterioration? Or not?

For the newer iPhone 11 or Xs, I haven't seen anything that suggests better accuracy. From what I've noticed, once a battery is below 90% capacity, it could be decent or it could be really bad. The "capacity" figure rarely shows a bad capacity figure (like 70% or 40%). In other words, once it's below 90%, user experience is more accurate.

 

[Ray2]

My old SE is going in for a battery replacement this week. Settings shows 88%, CoconutBattery shows 32%. My use experience suggests 32% is being kind. The numbers are 4 and 3 days old with an overnight charge in between. I've been through this with Apple as well. Bring down a useless battery but their diagnostics declares it just fine. Avoiding the need to swallow an AppleCare cost.

 

[now i see it]

It's not like anyone needs the battery health app. It's pretty obvious when the battery is getting old and needs to be replaced. The battery health app is like a thermometer. You can step outside and read the thermometer on the porch OR (I know this might sound shocking) you can feel the temperature with your skin.
The battery health app is same. It's very obvious when the battery is on its way out, but some people want to read a (inaccurate) gauge instead

 

[polyphenol]

It's not like anyone needs the battery health app. It's pretty obvious when the battery is getting old and needs to be replaced. The battery health app is like a thermometer. You can step outside and read the thermometer on the porch OR (I know this might sound shocking) you can feel the temperature with your skin.
The battery health app is same. It's very obvious when the battery is on its way out, but some people want to read a (inaccurate) gauge instead

I appreciate it is obvious my battery is knackered.

Just trying to find out if the reported value has any meaning or is so much junk. If I get a new phone, I'll keep an eye on the number from time to time, but only if it does have some validity.

(Where I am, the 3G/4G is incredibly variable. I suspect that has more effect than a few percent of battery capacity. But it does make it difficult to assess battery health by howlong it lasts between charges.)

 

[C DM]

It's not like anyone needs the battery health app. It's pretty obvious when the battery is getting old and needs to be replaced. The battery health app is like a thermometer. You can step outside and read the thermometer on the porch OR (I know this might sound shocking) you can feel the temperature with your skin.
The battery health app is same. It's very obvious when the battery is on its way out, but some people want to read a (inaccurate) gauge instead

Knowing the actual temperature still plays a role that tells more than what just simply feeling a more general feeling of hot or cold tells.

 

[MartyvH]

My 2017 SE has a Battery Health of 92% after a full Reset on iOS 13.7 but it needs charging three times a day. The utility of this screen size is diminishing so I'm waiting for the 12 Mini, rather than replacing the battery which would be reasonably priced.

 

[mebehere]

My iPhone 6, purchased at launch, showed 100% till I got the battery replaced when they were doing the new battery program. Obviously incorrect.

It was still at 100% when I traded it in for an XR 6 months after the XR release. Obviously incorrect.

XR still says 100%. My software must be buggered somehow.

 

[polyphenol]

I guess seeing 83% on a five-year-old device which has been used solidly is rather better than the 80% after 500 cycles that the blurb on the phone implies is normal.

But nice to know that I am not the only one questioning the accuracy.