Yes, indeed this is a good point: versatility. But then again, about battery packs: Why don't they make them intelligent so that both batteries help each other last longer? For instance, the kind of batteries iPhones have, live much longer when their charge does not overpass 96% and does not underpass around 12% (perhaps I'm now not being quite exact on these numbers but it is around this; Apple knows exactly their most efficient battery cicles, of course). Yet, despite their pollination marketing practices, they do not offer (nor third party Apple-certified makers have) a solution of a plugin battery that , for instance, would first charge your iPhone's battery until it reaches, let's say, 96% and then slowly charges the plugin battery overnight (if you plug it in at night and thus you have by default configure it as so ). And, also, this secondary battery could be automatically activated when the main iPhone's battery is getting close to the mentioned 12% or so (not before nor after)... This is what I'm talking about: instead of so fancy but inefficient wireless technology, they could use more efficient and intelligent (and thus ecological) technology with plugin batteries. After all, the battery is meant to always be attached to the phone so... just make a good plug-it-in one that communicates with the iPhone so that the life of the device's battery lasts longer and you feel like having a brand in your pocket that really contributes to a healthier environment and intelligent (and not just non-purpose fanciness) use of technology.
