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I am often disappointed by the battery life of my phone, but I think that what we need isn't bigger batteries, but better software. Supposedly, when working on

by ufmace 12y ago

I am often disappointed by the battery life of my phone, but I think that what we need isn't bigger batteries, but better software. Supposedly, when working on Lollipop, Google engineers left a Nexus phone running on Airplane mode, and it lasted a month on a charge. I'm not sure if it actually happened, but it's believable. Goes to show the point that if we can manage power usage well, multi-day run times are perfectly practical without mammoth batteries. I'm not sure what's going on with it in the iOS world, but Google seems to be working on this with the power management changes in Lollipop. They still have a long way to go, since the first thing I noticed on upgrading to it was random massive battery drain for no apparent reason. It seems to have gone away since I uninstalled Foursquare, but that was a random guess, and I'm still not sure if it was the main reason. Anyways, point is that the OS-level changes to make it easier to sip power are good, but app compliance is still spotty. I think that what we really need in Android is a good, OS-level way of monitoring which apps are actually causing idle wakelocks, GPS usage, and other non-obvious power drains. If the users can see that App X is what's killing their battery, they will presumably uninstall it and yell at the App developers instead of at Google, or maybe decide that the app does actually need to do that, and it's worth it, but at least they know it's the app's fault, and not Android's. Possibly some sort of option to notify the user if an app's idle power usage is over some threshold and ask them if they're really okay with that.

derekp7 12y ago
The thing I never understood -- back in the days of pagers, a pager could last for a month or more on a AA battery. A pager has to be constantly listening for a signal, then wake up and take action. So couldn't a phone be designed the same way? Have the main processor at idle, and offload event listening/processing to another low power processor chip. Then, wake up the main CPU when more advanced processing is required.
- jobposter1234 12y ago
  Umm... smart phones do this? It's a big reason phones can last so long with serious power requirements. A big reason for the phone/mobile specific chipsets was to enable these features.
  - derekp7 12y ago
    But what I'm still confused on -- if a pager can sit an listen to a signal for 2 - 4 weeks on a AA battery, why can't a phone (smart or otherwise) do the same thing? Or in other words, what specifically is there about listening for a "You have an incoming call" radio signal, that causes more power drain than listening for a "You have a page with this message contents" signal? For simplicity sake, lets assume even a dumb phone, with no internet -- just calls -- they never did have a fraction of the standby time of a pager.
    - jobposter1234 12y ago
      Late to see this. But the answer to your question is because even though they are superficially accomplishing the same end result, they are not nearly doing the same thing. Your smartphone is running a full blown modern operating system, with all the processors and memory and store requirements. The pager is likely running a very lean embedded processor and doesn't have nearly the same energy requirements.
    - k-mcgrady 12y ago
      >> "if a pager can sit an listen to a signal for 2 - 4 weeks on a AA battery, why can't a phone (smart or otherwise) do the same thing?" They do. For example the iPhone 6 Plus lasts 16 days on standby. Remember they also have to listen for other messages (push notifications, local notifications, alarms, calendar events etc.). Regarding your dumb phone statement they had about the same standby time as the iPhone 6 Plus I mentioned but they had much smaller batteries and the battery technology (I guess) was much less developed. [1] https://www.apple.com/uk/iphone-6/specs/ https://www.apple.com/uk/iphone-6/specs/
- ufmace 12y ago
  I haven't followed much what's been happening in mobile CPUs lately, but I remember reading at least a couple of years ago that they were already making multi-core CPUs set up to run a single core at low-speed, sometimes a specifically-designed low-power core, for routine sync tasks, and only fire up more CPUs and up-clock the running ones when required. I'm sure they're either doing it already, or have stopped for good reason. Another thing that I believe Android has built into Lollipop is trying to coalesce app syncs - instead of letting each app sync whenever it feels like it, group them all together to run at once, so you only fire up the CPU and radios once. I also wonder now how those pagers worked. Seems kinda impractical to listen continuously at those power levels. I wonder if the device polled the tower periodically, or only listened at some interval?
kruczek 12y ago
> Supposedly, when working on Lollipop, Google engineers left a Nexus phone running on Airplane mode, and it lasted a month on a charge. I find it quite believable. My own phone keeps working for around 20 days without recharging (and that is without Airplane mode - it has constant connection to the cellular network and occasional wifi or 3G connection).

by ufmace 12y ago

derekp7 12y ago

The thing I never understood -- back in the days of pagers, a pager could last for a month or more on a AA battery. A pager has to be constantly listening for a signal, then wake up and take action. So couldn't a phone be designed the same way? Have the main processor at idle, and offload event listening/processing to another low power processor chip. Then, wake up the main CPU when more advanced processing is required.

jobposter1234 12y ago
Umm... smart phones do this? It's a big reason phones can last so long with serious power requirements. A big reason for the phone/mobile specific chipsets was to enable these features.
- derekp7 12y ago
  But what I'm still confused on -- if a pager can sit an listen to a signal for 2 - 4 weeks on a AA battery, why can't a phone (smart or otherwise) do the same thing? Or in other words, what specifically is there about listening for a "You have an incoming call" radio signal, that causes more power drain than listening for a "You have a page with this message contents" signal? For simplicity sake, lets assume even a dumb phone, with no internet -- just calls -- they never did have a fraction of the standby time of a pager.
  - jobposter1234 12y ago
    Late to see this. But the answer to your question is because even though they are superficially accomplishing the same end result, they are not nearly doing the same thing. Your smartphone is running a full blown modern operating system, with all the processors and memory and store requirements. The pager is likely running a very lean embedded processor and doesn't have nearly the same energy requirements.
  - k-mcgrady 12y ago
    >> "if a pager can sit an listen to a signal for 2 - 4 weeks on a AA battery, why can't a phone (smart or otherwise) do the same thing?" They do. For example the iPhone 6 Plus lasts 16 days on standby. Remember they also have to listen for other messages (push notifications, local notifications, alarms, calendar events etc.). Regarding your dumb phone statement they had about the same standby time as the iPhone 6 Plus I mentioned but they had much smaller batteries and the battery technology (I guess) was much less developed. [1] https://www.apple.com/uk/iphone-6/specs/ https://www.apple.com/uk/iphone-6/specs/
ufmace 12y ago
I haven't followed much what's been happening in mobile CPUs lately, but I remember reading at least a couple of years ago that they were already making multi-core CPUs set up to run a single core at low-speed, sometimes a specifically-designed low-power core, for routine sync tasks, and only fire up more CPUs and up-clock the running ones when required. I'm sure they're either doing it already, or have stopped for good reason. Another thing that I believe Android has built into Lollipop is trying to coalesce app syncs - instead of letting each app sync whenever it feels like it, group them all together to run at once, so you only fire up the CPU and radios once. I also wonder now how those pagers worked. Seems kinda impractical to listen continuously at those power levels. I wonder if the device polled the tower periodically, or only listened at some interval?

kruczek 12y ago

> Supposedly, when working on Lollipop, Google engineers left a Nexus phone running on Airplane mode, and it lasted a month on a charge. I find it quite believable. My own phone keeps working for around 20 days without recharging (and that is without Airplane mode - it has constant connection to the cellular network and occasional wifi or 3G connection).