Battery optimization thread

[Guest Joshuah]

Hi Liquid users,

I didn't seem to find one of these threads yet.. so I thought i'd start one..

A lot of people have been complaining that recently that their battery life has decreased dramatically lately..

I dont know what the problem is, maybe bad Acer ROM ? Or something with the custom kernels going around?

What is everyones response to this?

apart from saying "Just disable auto sync/data/wifi" when you dont use it... (since this is what a smartphone is for..) lets look at other options, i.e. kernel optimization etc..

P.S i am running juice defender + ultimate... and advanced task killer pro.

I still get ~10% per hour drain when on idle... running 1.100.39 + LCR 1.7.3

[Guest Albert Poon]

Hi Liquid users,

I didn't seem to find one of these threads yet.. so I thought i'd start one..

A lot of people have been complaining that recently that their battery life has decreased dramatically lately..

I dont know what the problem is, maybe bad Acer ROM ? Or something with the custom kernels going around?

What is everyones response to this?

apart from saying "Just disable auto sync/data/wifi" when you dont use it... (since this is what a smartphone is for..) lets look at other options, i.e. kernel optimization etc..

P.S i am running juice defender + ultimate... and advanced task killer pro.

I still get ~10% per hour drain when on idle... running 1.100.39 + LCR 1.7.3

1. Try using the latest radio image

2. Try NOT using ATK

3. If you know when to disable auto sync/data/wifi etc, you don't need juice defender actually

4. Use Battery Information to fine tune your usage

[Guest Delnar_Ersike]

Acer's latest bin update have changed the radio a bit, and people are reporting a slight increase in battery drain in .39 compared to .05. Still, I think the impact negligible.

Depending on what rom you are using, battery usage can differ. In fact, battery usage can differ between different phones using the same ROM (the same way some phones are stable at higher frequencies than others). Some ROMs that are in development (like phh's FRF91) have known battery issues, and I've read about some LCR and Xian users whose battery drain is huge, but what I can say from my experience with Xian v1 is that battery usage is somewhat erratic. Some days, it's 5% an hour, other days it's 2% an hour.

A lot of apps drain your battery a lot, especially CPU intensive apps (games) or apps that use WiFi, GPS, and/or 3G (Google Maps running in the background is a frequently reoccurring example). If an app has a higher battery usage than 10%, it's worth looking into what causes the drain and/or stop using that app so frequently.

My tips for lowering battery drain (other than the standard turn off WiFi/GPS/3G/Bluetooth stuff): first and foremost, create a profile in SetCPU that sets the frequency to minimum (245 Mhz on most ROMs) and the governor to powersave whenever the screen turns off. There are a lot of apps that help reduce battery usage, such as Y5 (remembers your WiFi access points and automatically turns off WiFi when these access points are all out of range). Try to have widgets update as rarely as possible (clocks that show a second hand can drain your battery a lot), and try to reduce your screen brightness as much as possible. Live wallpapers might be pretty, but they consume their fair share of battery power, so try not to use them: if you absolutely need to have a live wallpaper, use one that isn't CPU intensive (like Galaxy or Grass). Make sure Android's built in autokiller kills unneeded apps at high memory levels (I use MinFreeManager). Create SetCPU profiles to lower the max frequency at lower battery levels, especially if you're using an OC'ed boot.img. Oh, and once in a while, let your battery drain all the way down to 0%, then charge it up to 100%: this helps your battery on the long run.

Edited August 3, 2010 by Delnar_Ersike

[Guest cubens]

I use the app Battery Monitor. In there is "Phone Test Info" - "Advance Settings" - "Show running processes" and you can see what is using your cpu atm. In idle there is normally just system_server: 5-8

[Guest sss_ddk]

Hi Liquid users,

I didn't seem to find one of these threads yet.. so I thought i'd start one..

A lot of people have been complaining that recently that their battery life has decreased dramatically lately..

I dont know what the problem is, maybe bad Acer ROM ? Or something with the custom kernels going around?

What is everyones response to this?

apart from saying "Just disable auto sync/data/wifi" when you dont use it... (since this is what a smartphone is for..) lets look at other options, i.e. kernel optimization etc..

P.S i am running juice defender + ultimate... and advanced task killer pro.

I still get ~10% per hour drain when on idle... running 1.100.39 + LCR 1.7.3

Two things i've noticed:

1-There is nothing that can drain your battery (including brpwsing, watching videos and listening to music) like GPS (google maps) and Gtalk. Well for GPS it is understandable, but gtalk???

2-There are times after an intense browsing session (:)), something seems to keep running in the system (unless you do a restart) and drains your battery quickly. so far haven't figured out what it was. Happens less on the .39 rom!

PS: I have good signal in my area.

[Guest Chadski]

switch to 2G if you have some background program that accesses the internet (Facebook, Twitter, Google Maps). This increase my battery life by 30%.

[Guest Quipeace]

switch to 2G if you have some background program that accesses the internet (Facebook, Twitter, Google Maps). This increase my battery life by 30%.

Even without a dataplan I noticed a difference in battery life when set on 2G, so it's worth setting it to 2G only.

I've had some situations on both Xians roms and the LCR releases where "Android System" would drain the battery in under 10 hours, rebooting wouldn't change anything but after a reflash the problem seems solved and the battery usage monitor is reporting normal values again.

Another battery saver can be to use an application that changes settings depending on what you do and where you are, like switching wifi off when you aren't near a known spot, and setting the data connection to GPRS when you have the screen turned off (for x seconds).

Also, even if a method only saves a tiny bit it's worth using anyway, especially something that you barely have to do anything for at all.

[Guest Chadski]

i think you are referring to a program called Locale.. Bad news is, it is not free. There is another one program like that also, I can't remember.. but still it is not free.. :)

[Guest HustlinDaily]

Fully charge your phone.

Turn your phone off.

Remove battery.

Never turn your phone on (unless it is plugged in).

BATTERY OPTIMIZED!

[Guest eumate]

Here's my suggestion, based on my usage (some call, some sms, mail notifications, a little browsing, no games, no music).

- use only stock kernel (for now), avoid overclocked ones and undervolted too.

- disable the light sensor and put the backlight to 0 or 25% when indoor (I use a widget to do that)

- always prefer 3g to wifi for background sync and browsing.

- always disconnect wifi after using it and use it only if necessary (use 3g instead if possible).

- remove the default acer widgets

- avoid live wallpapers

- don't leave any task killer in background (other than the default one, of course)

- use the power button to put the phone in sleep mode after you have 'awaken' it.

- use gps apps only when needed.

- never turn off it, put it in flight mode during the night.

Anyway the drain may vary depending on average distance/power saving modes supported from the cell/wifi router.

With these rules, it always lasts at least 2 days with 3g data connection always active and background sync active.

Edited August 3, 2010 by eumate

[Guest Ayur]

Two things i've noticed:

1-There is nothing that can drain your battery (including brpwsing, watching videos and listening to music) like GPS (google maps) and Gtalk. Well for GPS it is understandable, but gtalk???

Huh? I have Gtalk connected all the time, Sync per 3G and my battery consumption is still about 1% per hour.

@Chadski: Do you mean Tasker? Not free - but at least half the price :)

[Guest sss_ddk]

Huh? I have Gtalk connected all the time, Sync per 3G and my battery consumption is still about 1% per hour.

I was referring to using it (screen on + doing the actual chatting + a potential keyboard overhead) not just keeping it connected. Try it for an hour and tell me how much battery you have left.

[Guest Ayur]

I was referring to using it (screen on + doing the actual chatting + a potential keyboard overhead) not just keeping it connected. Try it for an hour and tell me how much battery you have left.

I did that and didn't notice any difference to any other services/apps which need the screen and an active data connection. The only reason I can think of (for a bigger consumption than other IMs in use) is: It's based on androids push-services. Should consume less when idle - but probably a bit more when (heavily) used (- but that's a wild guess ^^).

[Guest Liquidini]

I've had some situations on both Xians roms and the LCR releases where "Android System" would drain the battery in under 10 hours, rebooting wouldn't change anything but after a reflash the problem seems solved and the battery usage monitor is reporting normal values again.

i had the same problem with xian v1 and lcr 1.8 but now that i reflashed the 039 everything is ok with the battery. 0.4% per hour on idle

[Guest phhusson]

Depending on what rom you are using, battery usage can differ. In fact, battery usage can differ between different phones using the same ROM (the same way some phones are stable at higher frequencies than others).

IMHO the reason is most of the time not because of different phones, but because of different users... "Light" definition can change widely amongst users.

Some ROMs that are in development (like phh's FRF91) have known battery issues,

The only battery I know is that launching the camera app kills battery, but camera doesn't work, so it's not really an issue on itself.

My tips for lowering battery drain (other than the standard turn off WiFi/GPS/3G/Bluetooth stuff): first and foremost, create a profile in SetCPU that sets the frequency to minimum (245 Mhz on most ROMs) and the governor to powersave whenever the screen turns off.

Did you actually measure the difference between letting the system using its own frequency and forcing it to 245MHz ?

I'm pretty sure it will drains more battery than the opposite, but the difference should be really little.

There are a lot of apps that help reduce battery usage, such as Y5 (remembers your WiFi access points and automatically turns off WiFi when these access points are all out of range).

Ah thanks for that, I knew such apps but no name :)

Try to have widgets update as rarely as possible (clocks that show a second hand can drain your battery a lot), and try to reduce your screen brightness as much as possible.

These things are considered when "in use". AFAIK widgets are updated only when shown, I don't think people leave their home always on.

Make sure Android's built in autokiller kills unneeded apps at high memory levels (I use MinFreeManager).

Lolwat ? How is it related to battery ?

And MinFreeManager is just changing settings of something already enabled by default with quite aggressive settings for a 256MB device.

Create SetCPU profiles to lower the max frequency at lower battery levels, especially if you're using an OC'ed boot.img.

What's the point of doing it at lower battery level ?

If you want to extend battery life, you should do it always.

Lowering frequency at <10% will make you win 10% (remaining battery) * 30% (consumption gain (the gain depends on the actual use ...) ) = 3% of battery life...

Not mentionning that you make it so slow that everything it two times slower. (depends on the actual use again)

Oh, and once in a while, let your battery drain all the way down to 0%, then charge it up to 100%: this helps your battery on the long run.

Hum, I'm not sure that applies to phone's battery since their controler are plain stupid, not like laptop's batteries

I use the app Battery Monitor. In there is "Phone Test Info" - "Advance Settings" - "Show running processes" and you can see what is using your cpu atm. In idle there is normally just system_server: 5-8

Note that qualcomm have weird "idle" stuff, an app could be shown with high cpu consumption without actually consuming anything ...

Also this is true only for idle, not standby mode. (idle=the system is still running, standby = the cpu is totally off= suspend to ram)

Most of the time, the phone should be in standby mode, not idle. If it's most of the time in idle, then something's wrong.

Edited August 3, 2010 by phhusson

[Guest phhusson]

2nd post because modaco doesn't like too many quotes.

switch to 2G if you have some background program that accesses the internet (Facebook, Twitter, Google Maps). This increase my battery life by 30%.

For me, in an old building in which 3G reception is poor but works, it's more like *2 :)' (well on another phone)

I did that and didn't notice any difference to any other services/apps which need the screen and an active data connection. The only reason I can think of (for a bigger consumption than other IMs in use) is: It's based on androids push-services. Should consume less when idle - but probably a bit more when (heavily) used (- but that's a wild guess ^^).

There is no reason for it to use lmore when in use /o\

The only thing we could say is that XMPP is verbose and thus eats a lot of data, but I don't think that's enough to be releavant.

[Guest Ayur]

There is no reason for it to use lmore when in use /o\

The only thing we could say is that XMPP is verbose and thus eats a lot of data, but I don't think that's enough to be releavant.

I didn't really think that it would be relevant (and I didn't notice a bigger drain at all) - but the bigger overhead was the only thing that came to mind, which could lead to more consumption (at least theoretically).

[Guest jayziac]

- always prefer 3g to wifi for background sync and browsing.

- always disconnect wifi after using it and use it only if necessary (use 3g instead if possible).

- never turn off it, put it in flight mode during the night.

I think you have the 3g and wifi backwards. I remember a blog post where someone studied & recorded the original iphone's battery usage since it didn't have 3G (just wifi) and another iphone 3G, turned out wifi uses less power than 3G. Makes sense since the wireless transmission distance is a lot closer for wifi routers than the nearest cellphone tower. And for radiofrequencies, power ~= distance ^ 2

Also I turn off my phone at night instead of flight mode. Unless one believes that booting up Android & reloading the SIM contacts takes up more battery power than 8 hrs of flight mode.

[Guest phhusson]

Also I turn off my phone at night instead of flight mode. Unless one believes that booting up Android & reloading the SIM contacts takes up more battery power than 8 hrs of flight mode.

I believe so. On proper radios (I haven't checked if acer's is one of them), flight mode can do more than a week on smartphones.

[Guest eumate]

I think you have the 3g and wifi backwards. I remember a blog post where someone studied & recorded the original iphone's battery usage since it didn't have 3G (just wifi) and another iphone 3G, turned out wifi uses less power than 3G. Makes sense since the wireless transmission distance is a lot closer for wifi routers than the nearest cellphone tower. And for radiofrequencies, power ~= distance ^ 2

Also I turn off my phone at night instead of flight mode. Unless one believes that booting up Android & reloading the SIM contacts takes up more battery power than 8 hrs of flight mode.

3g surely has more 'per MB' battery usage than Wifi .

But Wifi (at least in our phones) drains battery alot faster than 3g when is active but idle, so isn't the best choice for background sync and for every app that uses background data connection.

With Wifi always active, at night my battery was around 30% and I had to recharge it every night.

With 3g always active, I can reach 3 days with fast dormancy enabled kernel (stock) and about 2 days with fast dormancy disabled (all the custom ones).

Of course results may vary depending on your 3g provider and local cells (distance, power saving modes etc).

So my advice is to use Wifi only for large data traffic or for long 'active' sessions and to disable it at the end.

[Guest Joshuah]

So should I set a profile for standby for lowest cpu for min and max since doesnot need much cpu in standby?

[Guest phhusson]

3g surely has more 'per MB' battery usage than Wifi .

But Wifi (at least in our phones) drains battery alot faster than 3g when is active but idle, so isn't the best choice for background sync and for every app that uses background data connection.

With Wifi always active, at night my battery was around 30% and I had to recharge it every night.

With 3g always active, I can reach 3 days with fast dormancy enabled kernel (stock) and about 2 days with fast dormancy disabled (all the custom ones).

Of course results may vary depending on your 3g provider and local cells (distance, power saving modes etc).

So my advice is to use Wifi only for large data traffic or for long 'active' sessions and to disable it at the end.

How do you enable fast dormancy ?

[Guest Liquidini]

So should I set a profile for standby for lowest cpu for min and max since doesnot need much cpu in standby?

grand malez said that if you use profiles in setcpu it asks for cpu state every 5 seconds so this may eat more battery

[Guest eumate]

How do you enable fast dormancy ?

Is enabled by default (at least on my network) with stock 09 and 39 kernel.

The status can be seen in the hidden menu (*#*#4636#*#*), advanced settings.

With custom kernels based on your git repository, it's disabled and trying to enable it from the menu has no effect (still disabled when back in the menu).

I've tried to search into the code and set some property like the N1 (i.e. ro.ril.fd) but still had no success in enabling it.

Even with undervolted kernel, this option seems to have the largest impact on battery life when using 3g data connections.

[Guest djinferno806]

grand malez said that if you use profiles in setcpu it asks for cpu state every 5 seconds so this may eat more battery

i knew that the profiles in setcpu run as a service in the background but i figured that after you manually set min freq as low as u can go and go into powersave governer when the screen is off, it still saves more battery then without setcpu.

Can somebody clarify please?

How does phh's 998mhz kernel handle frequencies on its own? does it ever go down to 245mhz as well? Im kind of curious now.