At the end of last year, I replaced an iPhone 7 Plus with an OnePlus 5T, after deciding against the iPhone 8 Plus (too similar to justify the upgrade) and the X (not worth the money). While researching this purchase, I couldn’t help notice the significant battery capacity difference between an iPhone 8 Plus (2,691mah) and the OnePlus 5T (3330mah). The much bigger battery on the OnePlus is surprising given that it is an almost-identical form factor, has a much larger full-front screen, and has a headphone jack.

Apple has been making phones for much longer than OnePlus and is a significantly bigger and better-funded company. So why are they selling phones that struggle to provide sufficient internal storage for their batteries?

To understand this, we need to look at the history of the iPhone 8. It’s the third revision of the iPhone 6 design that was introduced in 2014. But the original design actually had a larger battery – the 6 Plus has 2915mah. Each revision has made changes that affected the capacity:

1. In 2015, the 6S introduced 3D Touch, whose extra hardware reduced the battery capacity of the Plus-sized model by around 5%, to 2750mah.
2. In 2016, the iPhone 7 introduced a larger Taptic Engine, so something had to give to avoid fitting an even smaller battery than the 6S. This (not courage) is the real reason why the headphone socket was removed. It put battery capacity back in line with the original iPhone 6 Plus design, at 2900mah.
3. In 2017, the iPhone 8 introduced wireless charging, requiring an inductive coil and a glass back. This undid the gains made by the 7, and then some. Battery capacity fell to just 2,691mah on the Plus.

Whenever battery capacity was reduced in a new model, Apple always said that it wouldn’t make any difference because they offset the loss by efficiency improvements in software and hardware. This isn’t always the case. With the iPhone 6s, benchmarks by Ars Technica showed the 6S Plus battery life down by around 7% in the web browsing tests. Although the 7 improved matters, the 8 Plus came in around 4% worse than the 7.

3D Touch

Apple must have felt optimistic about the potential for 3D Touch because they decided it was worth the trade-off of a 5% reduction in a battery. As with the MacBook Pro’s Touch Bar, it’s clever technology but of debatable user benefit. Android doesn’t have an equivalent of 3D Touch, but it’s home screen icons offer very similar context menus from a long press, and it works perfectly well. 3D Touch doesn’t live up to its promise because iOS still has to support older devices without it. Look at how deleting an app still requires a long press on a 3D Touch phone. It could be much slicker as an option on the 3D Touch menu.

Wireless charging

With wireless charging, the trade-off is even bigger than 3D Touch – around 10% of battery capacity was sacrificed to make way for the glass back and inductive loop. Wireless charging should prove convenient and popular with users, so perhaps the trade-off is worth it, but 10% is a lot.

Screen technology

Almost all top-tier Android phones moved to OLED screen technology years ago, which is thinner than LCD because it requires no backlight. Until the iPhone X, Apple insisted that OLED screens weren’t good enough, and stayed with LCD. The combination of an LCD screen in a very thin phone does limit available space for other components.


After looking at the history of the 6/7/8 series of phones, a story emerges of repeatedly adding significant new technologies into a design that was made to be as thin as possible. Instead of redesigning the case to provide more internal space, compromises were made with battery capacity and the headphone jack. Given the premium price of the iPhone and the highly competitive smartphone sector, this is a questionable strategy. It’s as if Apple itself was unable to compromise and make the phone larger, lacking the confidence to deal with criticism.

With the iPhone X, Apple has switched to OLED screen technology and optimized its internal layout to accommodate a much larger battery relative to the size of the phone. Unfortunately, despite charging premium prices for the iPhone 8 with its four-year-old design, they think customers should pay a premium on top of that for a modern design.