According to KGI Securities analyst Ming-Chi Kuo, the iPhones that Apple (AAPL -1.00%) intends to introduce in the 2019 time-frame will include "upgraded 3D-sensing and AR-related functions," which will increase the power consumption of the devices compared with today's models. 

Since smartphone buyers tend to value the battery lives of their devices, Apple is going to want to pull out all the stops to ensure that its 2019 iPhones can deliver these enhanced features without sacrificing on usable battery life.

Apple's iPhones in a mosaic pattern.

Image source: Apple.

To that end, Kuo thinks Apple is working on upgraded battery capacity for its 2019 and 2020 iPhones. 

How Apple will pull it off

Kuo said that "Apple's key technologies, including semiconductor manufacturing processes, system-in-package (SIP), and substrate-like PCB (SLP), will create the required space for larger batteries." 

This might seem like a lot of technobabble, but once we go through it piece by piece, I think you'll see that it all makes perfect sense. 

The first part, "semiconductor manufacturing processes," refers to advancements in the technologies that are used to build key components inside the iPhone, like the applications processor (Apple's A-series chip) and the cellular modem inside. 

Apple's iPhone 6s.

Image source: Apple.

The applications processor and modem are the chips that consume the most power inside the iPhone, so I think Kuo is talking about advancements in manufacturing technology helping those products. 

Newer manufacturing technologies do sometimes lead to smaller chips, something that could reduce board space and increase room for battery capacity. But I don't think these will really be a driving factor for space reduction or battery capacity improvement -- instead, I think the more efficient manufacturing technologies will reduce power consumption and boost battery life for a given amount of capacity. 

Next on the list is "system-in-package (SIP)." According to chip packaging technology company Amkor, an SIP  is "characterized by any combination of one or more [integrated circuits] of different functionality" in a single chip package. 

This helps to reduce the area used by those chips, which can ultimately lead to a significant reduction in logic board area. Smaller logic board area means more room for battery capacity. 

Finally, Kuo mentions substrate-like PCB, or SLP technology. This technology, technology tear-down experts at TechInsights say, "are very high-density substrates." This technology is already used inside the iPhone X, TechInsights reveals, and so proliferation of the technology across Apple's future iPhone models should help drive battery capacity up. 

For some perspective, thanks to SLP technology, Apple was able to cram a larger battery inside the iPhone X than it was able to in the iPhone 8 Plus -- and the iPhone 8 Plus has a gargantuan physical footprint by comparison. 

Foolish takeaway

To the extent that Apple can boost the battery sizes inside its iPhones, the more feature-packed its devices can be. Kuo mentions 3D sensing as a key consumer of battery power, but that's not all Apple can do with larger batteries. 

Things like high-refresh rate displays, faster processors, larger and more powerful camera subsystems, and so on all use more power and Apple is fundamentally limited in the features that it can introduce by the amount of power the device consumes. 

Bigger batteries can help lead to better user experiences, so I have little doubt that Apple will try to move heaven and earth to endow future iPhones with increasingly large-capacity batteries.