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[Q] What technology improvements are needed to improve smartphone batteries?

Okay, needless to say, operating systems like iOS and Android are improving plus the new processors heading to dual core. However, battery technology is way behind I think. What improvements are needed in this field to get a smartphone working for a week on one charge (not realistic but ideal)?
Fuel cells?
New alloys?
What would work to help our battery technology which is falling behind?

Battery technology is far behind but it has been for over 100 years. For electric cars Toyota claims to have a new battery with 2-3x the power density of current batteries. Although for general purpose I believe Lithium Phosphate is still the current state of the art technology.
Fuel Cells are neat technology but not yet that practical just like 10year miniature nuclear cells.
The biggest problems in my opinion are
1. phone size (everything is getting so thin or small in general) leaving less room for a battery
2. screen size (huge touchscreen = big power draw), and other things too that impact battery life.
3. things that run in the background keeping the phone cpu in something other than its lowest power state
4. screen brightness. Seems trivial but can make a big difference and I think all phones should have ambient light sensors are change automatically.
5. internet connectivity. It goes along with #3 in that it wakes the cpu, but also the current wireless chipsets don't seem all that energy efficient. Using any connectivity cellular, wifi, or bluetooth really eats the battery. Many report turning off wifi, bluetooth, and using 2g when possible significantly improve battery life.
Personally I have the biggest battery I could get for my phone and my laptop too. My 17" laptop runs 4.5 hrs at lowest brightness and 3 hrs at the brightest setting. Most phones aren't much different.
Sorry long rant...... does that break down your question correctly?

landoftheeskimos said:
Battery technology is far behind but it has been for over 100 years. For electric cars Toyota claims to have a new battery with 2-3x the power density of current batteries. Although for general purpose I believe Lithium Phosphate is still the current state of the art technology.
Fuel Cells are neat technology but not yet that practical just like 10year miniature nuclear cells.
The biggest problems in my opinion are
1. phone size (everything is getting so thin or small in general) leaving less room for a battery
2. screen size (huge touchscreen = big power draw), and other things too that impact battery life.
3. things that run in the background keeping the phone cpu in something other than its lowest power state
4. screen brightness. Seems trivial but can make a big difference and I think all phones should have ambient light sensors are change automatically.
5. internet connectivity. It goes along with #3 in that it wakes the cpu, but also the current wireless chipsets don't seem all that energy efficient. Using any connectivity cellular, wifi, or bluetooth really eats the battery. Many report turning off wifi, bluetooth, and using 2g when possible significantly improve battery life.
Personally I have the biggest battery I could get for my phone and my laptop too. My 17" laptop runs 4.5 hrs at lowest brightness and 3 hrs at the brightest setting. Most phones aren't much different.
Sorry long rant...... does that break down your question correctly?
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It sure does for me thanks

nova display and amoled plus is good for battery
li-po is more efficient than li-ion
dual core is more efficient about 40% than single core (in ginger bread)

my philosophy on overclocking

Seems like some recurring discussion in past threads:
1 - why should we even bother overclocking if we’re not a gamer.
2 - won’t we damage our device with overclocking.
I haven’t seen definitive answers posted anywhere, and I certainly don’t have one.
Maybe in that case (I have no definitive answer), I should probably just keep my mouth shut.
It may be the case, if so let me know.
For whatever reason, I have some strong opinions and I feel it would be useful to share my opinions and the reasons I have formed those opinions.
Take them or leave them or add to them... up to you.
Point out to me if you think I am grossly mistaken.
1 - why should we even bother overclocking if we’re not a gamer.
Click to expand...
Click to collapse
There is constant tradeoff between battery and performance.
Underclocking will help you save battery. How low you want to underclock depends on what you can tolerate.
But what you can tolerate depends on your user experience, which can be dramatically impacted by use of overclocking at other times.
The perfect example for me is a program which is slow to start up. In my case it is Memento database with 1000+ records, takes a long time to read in (I think the program does some sorting every time it opens). That is a minor annoyance. If I were to underclock it will start even slower, I’m going to get impatient and set my speed back up.
But think about this:
1 - Using Tasker you can apply cpu profiles upon application launch and remove them after a predetermined length of time. I can give the program a blast of 1600M-hz when it starts, then set it back where it was after predetermined period (for example 10 seconds).
2 – Setcpu is not quite as flexible as tasker in this regard. With setcpu we can create a profile to occur when we launch the program like Memento, but we just can’t incorproate a time delay into the logic (it will stay on the higher profile as long as the program runs in the foreground).
3 - There may be circumstances where this setcpu behavior is what you want... it will give you faster response whenever the program is in the foreground, and will yield to lower priority profiles whenever the program goes to the backghround.
(I haven’t investigated how to make make Tasker and setcpu play nicely together yet).
So, if you speed up the things that cause noticeable delay for only a short time, or particular applications which seem to run slow then you can probably be more satisfied with your underclock in the other times. In the overall picture, I think the overclock capability can ironically be used as part of a strategy to save battery (unless you just like overclocking just to see things zip accross your desktop and menu’s pop in and out faster than you can blink, I’m starting to get spoiled with that behavior on my phone in its new configuration, partially from overclock..I’m sure others get even better in their configuations..).
2 - won’t we damage our device with overclocking.
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Click to collapse
On this I would say no, as long as you are careful about not running it in conditions that create high temperature. .
(you may have stability problems as you guys know, an entirely different subject).
The physics of the damage are all related to temperature. There are many variables affecting temperature that the designer is unaware of and so he builds in margin for the worst cause unknown future occurence (he has to consider maybe phone will be in desert with 100F ambient, and on the charger, while the user tries some heavy surfing with gps, all at the same time, so he limits cpu to 1200Mhz).
We on the other hand know what are the conditions of our phone and what it’s likely to see and what it’s doing at any given time, and setcpu provides additional ability to monitor and adjust.
Here are example setcpu profiles I came up with to protect myself from damaging temperatures (Zen's kernel A/1600)
Priority 100: If batter temperature > 50C (122F),establish conservative governor 100-400Mhz
Priority 90: If batter temperature > 45C (113F),establish conservative governor 100-800Mhz
Priority 80: If battery temperature > 40C (104F), establish conservative governor 100-1200Mhz (in the event I was overclocking, this profile will stop it when battery temp exceeds 40C, all other profiles that may invoke overclocking are lower priority than 80).
This is just from judgement, knowing that I’m normally < 104F battery temp during light use and don’t want to overclock when I’m outside that normal light use zone. Some further curtailment of cpu max frequency occurs as battery temperature climbs above that. (which I would not have even had the benefit of if I were casual user with no overclocking and no setcpu).
As long as you’re limiting temperature, you should not be worried about damage imo. By the way, of course overclocking is not the only thing to affect temperature: things like phone case (thermal insulation), charging, gps, heavy use etc all have an effect. I'm not quite sure why sometime cpu overclocking gets singled out in a dangerous category all its own without any discussion of other things that affect tempertaure.
In fairness, you may point out that what we monitor is battery temperature and not the same thing as cpu temperature. It’s a good point. Increase in heat generated at the cpu causes more of an increase in temperature at the cpu then it does at the battery. But it's question of how much different. there's a matter of how much. Why do you think it is that Samsung didn’t give us cpu temperature indication? I think because they knew battery temperature is close enough. Even on newer flagship Behemoth Samsung Note, I’ve read you still only get battery temperature, no cpu temperature. If cpu temperature was that much different, they surely would have provided a separate indication of cpu temperature (cpu is after all a much more critical component than replaceable battery).
And why should we expect battery temperature to be representative of cpu temperature on our phone, when the same is not true on a pc? I think I can answer that:
* PC has things all spread out. There is air flowing through. The air picks up heat from each component from heat sinks by convection. The component temperatures are not tightly coupled together.
* Phone (in contrast to pc) has everything compact inside one itsy bitsy case. There is no air flowing through. That means heat transfer inside the phone is not by convection but by conduction. For most effective conduction, all components are attached with high thermal-conductivity path to the phone structure and the exterior surface of the phone. The heat transfer from phone to ambient is primarily convection. So we have effective heat transfer (conduction) among the components of the phone and less- effective heat transfer (from phone to environment). It tends to tell us that there will not be big difference in temperature among phone components. The big temperature difference that occurs is between the phone and the ambient air.
I don't have access to a phone which has both cpu and battery temperature indicators. If someone does, it would be interesting to hear how close those two temperatures follow each other.
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Edited to add: searching other threads suggests there can maybe be a substantial differencebetween cpu temperature and battery temperature. That makes me a little less certain. At least we can use battery temperature as a gross indicator that the cpu isn't seeing excessive extra heat from other non-cpu sources while we're overclocking it. Certainly having profiles in place to limit overclocking when battery temperature is high can only help protect us. But is it a false sense of security which can lead us astray? I dunno. I have already done a stability test at 1600 for quite awhile and there's no damage in sight, so if there is any damage potential, then it is only an accumulation over time. I don't plan on leaving Fmax at 1600 all the time anyway, since it would kill the battery. My planned strategy reserves the 1600 overclock for occasional playing around, and boosts when I need them like like my Memento database. My gut says that approach is just fine. Interested in hearing any other thoughts, experiences, links that may shed light.

[Advice] More powerful batteries for Devices?[Micromax A89 example]

Hi people, I searched though quite a few threads and couldn't actually find an exact answer.It also can be a general question for any device.
I have a Micromax A89-good handset for its price only problem is the battery - it wouldn't last much (i'd say 3/4 a day normal use-1450mAh).
My question is what are the subtleties involved in powering such a device with more powerful batteries like a 2600 mAh battery (approx same size). Will it just work fine, giving better battery power to the device. Or whole lot of things come into play? like software and everything or the Soc itself which is made to work within certain range (this one doesn't for your knowledge -same Soc is present on a higher end device a110 with 2100 mAh battery).
Or it may damage or brick your device or may be heating problems occur, there are lots of factors.
So if i can find a similar battery that could fit in - no matter how powerful it is 5000mAh or whatever- do i get approx 3x battery life? or it cant be done?
and making it a more concrete i'd love to get battery suggestions for A89.
Thanks

Undervolting

Hello guys
I'm not a new user in kernels or ROMs .
I have a low-decent battery life ,and I'm sure there's a way to get a better battery life with undervolting .
I want to know
what is "undervolting" ?
What is the biggest damage it can cause?
What is PVS?
How do I know ,how much I can UV?
What are the steps to undervolt?
What I gain from UV (despite battery life)?
For your info ,I'm using AOSPAL ROM +FAUX's latest 16u kernel .
Thanks
Sent from my Nexus 5 using XDA Premium 4 mobile app

http://forum.xda-developers.com/showthread.php?t=2537000
Sent from my Nexus 5 using Tapatalk

Hi,
Most of your questions have a reply:
About undervolting: http://forum.xda-developers.com/google-nexus-5/general/nexus-5-undervolting-thread-t2537000.
CPU binning: http://forum.xda-developers.com/google-nexus-5/general/cpu-binning-nexus-5-t2515593.
The "risks" are instability like hard reboot, SOD, etc.... To find a "safe" value you will need to test by yourself to find what undervolting your CPU can handle, not all CPU's are equals.
Undervolt by steps like - 25mV, don't set your new values at boot unless your are sure it's stable (or you could encounter bootloop), test for a few days under different conditions (as your use).
The gain apart battery life (but you will not gain that much as people tend to think) is a little less heat, but again nothing huge..., better is to test by yourself and see what you will gain... or not.
Battery life depends mainly of your use, apps, signal quality and settings like, screen brightness, synchro, CPU governor, etc... In my opinion check first what could be the cause of your low battery life (and what is low battery life for you???) before play with undervolting.

As said above, undervolting will get you very minor battery life increases.
More than likely you have an issue, or its just your setup and usage giving you the battery life you are seeing.
Undervolting will not change any of this.... You'll gain only minutes of battery time.
Try some troubleshooting in the below thread to see if you have an issue, or how to setup for better battery life. Read through it a bit, from the last page and work back a bit. You can post meaningful screenshots there too. From gsam or BBS.... not the stock battery screen, it has no real useful info for finding issues. Good luck!!
http://forum.xda-developers.com/showthread.php?t=2509132
Nexus 5 Battery Results

I've been undervolting many systems for many years, primarily Linux desktops and some servers, and the primary benefit is that you get less heat output which means when running cpu-intensive tasks the temperature climbs slower so the throttling of the clockspeed kicks in later, so your phone will be faster in certain situations. If you take a phone which has been idle for a while and run a benchmark, and then immediately run that benchmark again, the 2nd time gets a lower result as the phone is still hot from the 1st. This makes drawing conclusions about settings really dificult but it illustrate that throttling from heat is affecting speed.
For most users their perception will be the phone runs cooler.
You do undervolt at each step in the processor's frequency, and each step is a trial+error activity, the throttling I mention means finding a stable under-volt at the higher frequency which is labour-intensive,i.e take the max clock, and undervolt it a little, run a benchmark which forces it to run at high clockspeed, and if it passes that test then run it again at the next step down in frequency. Once you've got the most stable top clockspeed, then do it progressively for all the other voltages on the way down.
In some platforms in Linux and Windoze, we wrote scripts which save the stable voltages and then undervolts a little and runs a stress-testing benchmark and if the system hung it wouldn't save the current voltages so the previous higher voltages were safer, stick that script in a startup script area and leave the compute to do many self resets, and you've calculated your device's voltage range. I wonder if someone has that done for Android??? For a laptop the FAN would run slower saving battery time and for laptops that would lead to say 20% better battery life but on a phone it won't make much saving as no fan.
Your phone will run most of its time (like 95%) at its lowest frequency, so for effort/benefit just focusing on dropping its voltage will gain the most in the phone running cooler.
Battery life improvement is marginal, if you look at your battery stats its down to your application settings and screen brightness, i.e. how you use and what you do with your phone. So if your battery life is bad, use your phone less!
I carry a slim USB battery, it is the $/effort/benefit the best thing you can do, $20 doubles your battery life, if you get one with a 1.5A-2A output in just a few minutes when the phone doesn't mind a battery attached, will dwarth every possible tweak and hack anyone can form in benefit.

Battery manufacturers/suppliers for smartphones ?

In smartphones today, we can easily get information on their CPUs/GPUs etc.
But the only thing they mention about the battery is its capacity.
is it possible that some batteries from particular manufacturers would have better charge retaining properties or overall lifetime ?
Is it known whether batteries of say Samsung/HTC/Moto/Asus phones are generally better or worse than others ?
Or it does not matter, and mostly depends on the CPU/GPU and how the software handles the consumption/wakelocks etc ?