If this and other rumours are true then:
From Apple specs, iPhone 4S height x width = 115.2mm x 58.6mm
From this article, internal width for battery in iPhone 4S = 4.3mm
That gives a theoretical maximum internal battery volume of 29,028 cubic millimeters in the iPhone 4S.
From other rumours about the next iPhone the rumoured height x width = 58.47mm x 123.83mm (source:
https://www.macrumors.com/2012/06/2...evice-dock-connector-said-to-include-19-pins/). Note discrepancy in rumoured thickness vs this article by the way.
From this article, internal width for battery in next iPhone = 3.84 mm
That gives a theoretical maximum internal battery volume of 27,803 cubic millimeters for the next iPhone which is 95.8% of the iPhone 4S.
The above are theoretical maxima which could never be achieved because the electronics also needs to share that space but various other rumours point towards Apple taking aggressive steps to minimise the volume taken up by some of the electronics (rumours include a smaller docking connector and using nano-SIM). Higher levels of integration from the rest of the electronics plus a move to 32nm for the Soc should also help maximise the volume left over for the battery.
When all of the above is taken together I would expect, if the rumoured dimensions are accurate, that the charge capacity of the next iPhone's battery will be at least equal to that of the current iPhone 4S and possibly even a tiny bit bigger. That then leaves us to see what other tweaks Apple might be able to make to the electronics to reduce their power consumption although, when looking at this final piece of the jigsaw, LTE and the bigger screen are the big unknowns since they, especially LTE, could have a detrimental effect on power draw.
- Julian (who also cares a lot about battery life)