13th September 2019

In recent years, the expected battery life of new iPhones have always been given in relative values. I saw this as a challenge to try and calculate what the raw number is.

The first place I went to was the technical specifications pages for the three new phones, the 11, 11 Pro, and 11 Pro Max. They all had relative values based on the previous generation. Of course, my next step was to look at those values. Again, they were relative.

So I followed the chain until I came to the iPhone 6s and 6s Plus. Their technical specifications no relative or fixed estimates for the battery life. There were estimates for audio playback, video playback, internet usage, etc. But I just wanted a single figure for an estimated use. As that’s what I expect the relative values on recent iPhones to be based on.

As far as I can tell, Apple didn’t talk about the battery life of the 6s generation iPhones when they were first announced. Therefore, I’m going to be basing these on overall estimates that I’ve found online. The numbers I found from various tests were around 8 hours for the 6s, and 10 hours for the 6s Plus.

Using these numbers, I calculated the estimated battery life for the 11 iPhones that were released since.

Here are the numbers (all amounts in hours):

iPhone Relative Values Resolved Values
6s 8
6s Plus 10
7 6s + 2 10
7 Plus 6s Plus + 1 11
8 7 10
8 Plus 7 Plus 11
X 7 + 2 12
XR 8 Plus + 1.5 12.5
XS X + 0.5 12.5
XS Max X + 1.5 13.5
11 XR + 1 13.5
11 Pro XS + 4 16.5
11 Pro Max XS Max + 5 18.5

One thing to point out is that the XR and XS batteries seem to last the same amount of time-based on the 6s/6s Plus estimated values, and then following Apple’s information. It was widely reported that the XR has superior battery life, which makes the numbers seem a bit odd.

But then again, we don’t know what type of data Apple is using for their estimates. Are they going on values that they have for a brand new iPhone when it was announced? Or are they based on the previous generation, but running the most up to date version of iOS? A lot of these things can skew the results.

While I would have preferred if along the chain there was at least one fixed overall value I could have used for a base. However, I do find the data to be interesting. Even if you just look at the relative differences between them. For example, we don’t know the official estimates for the 6s/6s Plus, but we do know that the 11 Pro Max supposedly lasts 8.5 hours longer than the 6s Plus. So a rough 2 hours increase in battery length every year.


Update:

To help visualise the data, here are two charts. The first using only the relative values that Apple provide, and the second including the estimate base values for the iPhone 6s and 6s Plus.

iPhone Battery Life Changes Relative to iPhone 6S and 6S Plus (in Hours)

iPhone Battery Life Using Estimated Base Values for iPhone 6S and 6S Plus (in Hours)