[olla]

The real blocker of going electric on everything is the capacity of rechargeable technologies and their lifetime, not some global conspiracy. Even the high price of batteries/capacitors might not be a problem if lifetime and capacity would be great. In that sense Musk might be onto something, but I think it takes a lot more than 20% improvement over current technologies for batteries to become feasible for storing electricity on large scale. If a smartphone could be done with a battery, that lasts a week and is not dead within a year in winter conditions, it probably would have been done allready.

[higherpurpose]

A smartphone with a week of battery life is likely to be possible now. Just do this:

1) use the latest most efficient panel technology - let's say the latest Super AMOLED from Samsung

2) Use a very lower resolution such as 480x320 (also the initial resolution of the iPhone, which many thought looked "great" a few years ago)

3) Put a screen that's as small as possible on it - let's say 3.5" (you now...the "ideal" size that the iPhone used to have?)

4) Put the lowest power chip you can find in it (even if that means lowest performance - although a single-core 1 Ghz Cortex A7 should do the trick).

5) Put a relatively powerful (enough to handle that resolution easily), but very efficient GPU in it

6) Use other components that are also cutting edge in terms of power efficiency.

7) Put a 3,000-3,500mAh battery in it, even if it makes the phone 10-12mm thick (so like the Nokia Lumia 900 that many liked at the time for its "design", despite its thickness).

I would be surprised if all of this didn't lead to a week of battery life for the phone. The "problem" is this phone will be quite expensive unlocked (probably close to $300) due to its cutting edge/more efficient components, yet at the same time it will look like a $100 cheap phone in terms of "specs".

So where I'm going with this is that the market doesn't want such a phone even if it has a "1 week battery life". The market wants "PC-like performance", 2k resolutions and 5.5" screens more than they want "1 week battery life". And the other problem is that they want those specs to keep going up, and as long as those go up, battery life can't go up much either.

They optimize for performance and high specs rather than battery life. So if an OEM can choose between a 1080p panel with 30 percent less power consumption and a 2k panel with the same power consumption, they go for the 2k. And that's how our phones get stuck forever in the ~1 day battery life.

[Symmetry]

You're forgetting the power draw of the radio. To actually last a week on 3,000mAh you'd probably be stuck with EDGE at best.

[mikeash]

Smartphone batteries could easily last a week right now, with current technology. The reason they don't is because manufacturers prefer smaller size and lower weight to longer battery life, presumably because their customers do.

Size and weight are much less of a concern for fixed installation grid storage, of course.

[mFixman]

> Smartphone batteries could easily last a week right now, with current technology.

Source? I always assumed the the main reason why modern cellphones' battery life is a lot worse than a few years ago was because of power-hungry processors and screens.

[mikeash]

I don't think you really need a source for this. Current smartphone batteries last about a day in normal use. If you made it seven times larger, it would still be portable (just less so), and would now last a week. Increasing battery capacity by just adding more battery is trivial. What's hard is adding capacity without adding bulk or cost.

[olla]

Yes, bulk is quite important factor too, especially on storing energy on large scale. Agreeing with the "can do a week of battery phone" on the other hand depends. The problem is that smart-phones have achieved lately their acceptable speeds with quad core (and up) processors. Resolution of screen makes less impact than the mere size of the area that has to be lit, but nobody wants to surf web through a peephole. E-ink would rescue if it could play videos and games fast. A lot of people want to do exactly that. And there are a lot of additional features we are used to keeping active (gps, wifi, ...). Turning these off will decrease the value of having a smartphone. Based on current battery sizes a week of battery would probably mean about 5 times the battery of phones now. That is not pocketable computer territory anymore.

In addition I would really like to have the phone component moved to watches (with at least 3 days battery) and leave all the rest for a pocketable computer to handle.

[MichaelGG]

The Huawei Mate 2 has a 4000mah battery and I regularly get two days (30-40 hours) on it. It's very handy never having to worry about charging. It's thin and light (cheap feeling). As much at it sucks from crappy software (messed up version of Jelly Bean) and as much as I want to leave Google, no one else seems to be targeting even 20 hours of life. It's very frustrating.

The Mate 2 feels small enough that doubling the thickness would still result in an acceptable phone.

[nradov]

Why worry about smartphone battery life? It takes less than a minute to swap the dead battery with a fresh one and be back up and running.