I took my three year old iPhone 6 to the Apple Store in Tampa today and the man talked me out of getting a replacement battery. Is this a scam? Is Apple just wanting to save the cost of replacing my battery?

https://www.apple.com/iphone-battery-and-performance/ - December 28, 2017 A Message to Our Customers about iPhone Batteries and Performance

iPhone Battery and Performance - https://support.apple.com/HT208387 - about power management, battery life

Checking battery health using Console - https://discussions.apple.com/thread/8308874?answerId=33120652022#33120652022

iPhone Battery & Power Repair - https://support.apple.com/iphone/repair/battery-power - battery replacement and cost - Read the bottom section of this article.

iPhone 6s Program for Unexpected Shutdown Issues - https://www.apple.com/support/iphone6s-unexpectedshutdown/

How to find your nearest Apple Authorized Service Provider (AASP) or Apple Authorized Distributor (AAD) - https://locate.apple.com/country

Genius Bar appointment - https://www.apple.com/retail/geniusbar/

When Apple revealed/admitted that they slowed down iPhone devices to help with unexpected shutdowns there was an outcry from the public that Apple had no right to slow down their devices. Apple will be releasing an iOS update soon that will allow people to turn off this feature (which is a bad idea but that's for another post). In order to appease to the customers Apple introduced the $29 battery replacement program so that those with batteries that had degraded too much would no longer have a slower device. Once the battery is new then the OS doesn't need to be slowed down anymore. Originally Apple was only going to replace the battery if their existing battery was causing their iPhone to be slower. However, Apple decided to go ahead and just let anyone that wanted a new battery to get it for the $29. Apple employees are told to let people know if it's going to help their device and save them $29 if it's not. There's really no reason to pay $29 for something if it's not going to help. Not to mention it frees up stock and labor for those people that really need to get replacements.

As long as your battery isn't too degraded, replacing the battery isn't going to help. Did they run a diagnostics on your device when you were in the store? If you insist that they replace it they are supposed to but more than likely he was telling you the truth and wanted to save you $29.

charles6 wrote:

Diagnostics said my battery was as good as new. But my experience with the phone tells me it runs down noticeably more quickly than when it was new. So who is right?

You're probably not going to like this answer but, the diagnostics is probably correct. We humans are very good at convincing ourselves that our observations and memories are more accurate than they are.

Also, you may have turned on more apps in Settings>General>Background App Refresh or added apps that use more power.

charles6 wrote:

Diagnostics said my battery was as good as new. But my experience with the phone tells me it runs down noticeably more quickly than when it was new. So who is right?

Did they give you an exact number? The industry standard is 80% original battery capacity. If it's 3 years old I would expect that it would at the very least be down to at least 90% if it's been used a lot. I certainly wouldn't expect new. If you have a Mac, you can try using coconutBattery. There's also a free app called "Battery Life". I think it's kind of clunky and it sends the user to a lot of ads, but it's free and it does show basic battery health reduction.

https://www.coconut-flavour.com/coconutbattery/

A lot of issues that seem like they're battery related are more about usage patterns or perhaps iOS changes that affect power consumption. In order to get a longer battery life, the power management has to be able to reduce power consumption, but without noticeably affecting the user experience.

I wouldn't necessarily say it isn't worthwhile to get a new battery. As far we know this battery promotion ceases at the end of 2018, and certainly it's not a bad thing to have a completely new battery. Apple's previous policy was that they or an AASP wouldn't perform a battery service unless it didn't pass the standard battery diagnostic for diminished capacity.

Diagnostic tests should be more accurate than what a user perceives. Some updates to apps may use more power or have more things to load. Brightness and volume levels can make a difference. One thing I have done before is to turn on a long movie (e.g. Lord of the Rings) in airplane mode at 50% brightness and 50% volume when the battery is fully charged and see what the battery level is after it plays the complete movie. If you feel the battery isn’t working well run the same test later.

IdrisSeabright wrote:

You're probably not going to like this answer but, the diagnostics is probably correct. We humans are very good at convincing ourselves that our observations and memories are more accurate than they are.

"Good as new" was probably an overstatement, but that it would pass the diagnostic after 3 years wouldn't be surprising.

anypats wrote:

Diagnostic tests should be more accurate than what a user perceives.

Remaining battery capacity is still just an estimate though. It's impractical to probe into a battery for remaining capacity, and in any case there's more than just X amount of electrons available since it's also about being able to provide enough current/voltage. You can run battery diagnostics and one day it might be reading out 97% and the next day 92%. Ambient temperature will affect the reading. It's all based on monitoring how the battery is charging, discharging, number of cycles, temperature, and current/voltage. We've all heard of older batteries that were indicating 40% and then suddenly dipped to 10%. That's the estimation model breaking down with an older battery.

That being said, under the current promotion they're supposed to allow the customer one shot at a battery at the promotional service price even if the battery passes the diagnostic.

charles6 wrote:

Assuming I have a 4-Bar ATT signal, almost no background stuff enabled and only Safari and message apps running, with a new how long should I be able to surf non video websites? 8 hours? 10 hours? More.

It really depends on the content. A lot of websites have ads that float over the main page and they can be total battery killers. If you're just reading it that's one thing, but CPU usage will spike as you move to a new URL (while it parses the content) and then settle down. Surfing the web is a lot more complicated than the days of just plain text and images in HTML. Of course mobile websites are coded differently, but if I go to my favorite news website I see the CPU activity on my Mac spike up to over 100% (there are two cores) for a few seconds until it settles down.

charles6 wrote:

Are there any iPhones that can actually get 10 hours of safari use? I have heard people claim that they do. Mine will not.

Maybe. It's somewhat of a best case scenario.

You might want to see what's using up the charge. Go to Settings>Battery and look at the bottom under "BATTERY USAGE". It's probably not going to tell you anything more than Safari is using the most power, but you might able to see if maybe something else is consuming a lot of the battery.