Carrying around bulky power banks or worse, chargers to then tie you to sit close to an outlet and wait for the battery to charge, is not entirely ideal when you're on the go, foreign or domestic. It's also less anxiety-inducing to not have to worry about where will I get my next charge and how long will it interrupt my plans for.
Power banks come in different sizes. The bigger ones also allow to recharge your phone several times. There are also small and light ones that contains energy for one full charge or less.
I agree with your point completely but that use case is an edge case, would it be worth it regulating all phone design in order to address such a specific scenario?
Such use cases are normally handled by creating specialty products.
I've got a little 2_000mAh 3.7V (7.4Wh) USB battery pack here that was vendor swag from a conference, a probably 3.7v? 10_000mAh () that I'll then assume is ~37Wh. and a Canon NB-13L 3.6V 1250mAh (4.5Wh battery pack) for my camera.
For mm^3/Wh, the results are:
Small vendor swag power bank:
96 x 21 x 26
52_416 / 7.4
7,083 <-- worst one
Canon battery:
42 x 30 x 9
11_340 / 4.5
2,520 <-- wow that's way less
10,000mAh dual USB power bank:
139 x 22 x 60
183_480 / 37_000
~5 <-- wow
By volume / energy, the big power bank wins by a mile. And tbh its not that huge, similar footprint to my phone and about twice as thick. Plus, it can power two devices at once, which can be pretty handy. It has a bit over twice as much power as my phone's battery. This logically makes some sense, as phones these days are pretty much a battery and a screen with a small logic board tagging along for the ride.
If I'm on the go, I'd much rather have a large battery bank that provides a good bit of flexibility rather than a battery that only works with a single device. This one battery pack can charge my phone, my camera, my wireless mouse, my keyboard, my headphones, my e-reader, and then all the same list of stuff for my spouse. If I got a fancier one, it could even provide extra juice to my laptop. If I only had a battery specifically made for my phone, I'd only be able to swap out my phone battery and all of the rest of my devices would need their own batteries or just be left dead.
On top of that, if I wanted to then charge that battery outside of the phone I'd have to lug some specific charger for that model of battery. Meanwhile if I bothered getting a newer USB-C power pack the same power cable that charges my laptop and my phone and my headphones can also recharge my spare battery along with all the rest of the devices I mentioned. I'm much happier having a 10,000mAh battery pack in my backpack to recharge when needed than needing to think about having a few different batteries around and their related chargers to keep track of. Once this one dies I'll probably
When battery life is a concern, I carry around a small flashlight and a (very) short USB cable. The flashlight can both receive charge (from the wall) and send charge (to the phone) through its USB port.
Lots of high-end flashlights do this. Mine isn't much larger than the 21700 cell it contains. If you want to go smaller you can get a 1850-based flashlight and still almost double the capacity of your phone.
I don't understand. Why won't it fully charge the phone? And you can use the phone while it's plugged in. In all respects it gives you ~2X the number of useful hours at the cost of having to carry around a very small item.
