Improving battery life

[rome425]

Has anyone tried this on Nexus One?

http://forum.xda-developers.com/showthread.php?t=670999

"GSM auto (PRL)" works on AT&T Nexus, I don't know if it improves the battery life over "WCDMA preferred"

***EDIT***

Looks like this process works by improving battery life when phone is idle. Here are the instructions from the first original post.

1) Goto dialer and dial *#*#4636#*#* (DO NOT press send)
wait a second and you will get the test menu.
2) In the test menu choose 'Phone Information'
3) scroll down and choose on the first drop down - GSM auto (PRL) (for high speed data) or GSM only (You may get 3g if not use GSM auto (PRL)) Don't know what PRL means, but GSM auto (PRL) allows High speed data HSDPA (it was previously on GSM/CDMA auto(PRL) I think.)
4) Back all the way out.
5) You might want to reboot, but I found the settings worked straight away.
Edit 3 - I don't take any responsibility for step 6 -
6) Try other settings on the dropdown if you are brave as I don't know the consequencies of using settings like "EvDo only" and "unknown" as they may be better depending on the way your provider provides information.

Edit 4 - can't seem to select the other settings like EvDo and unkown anyway.

Edit 3 - TBH - GSM auto (PRL) is working for me with HSDPA and I will try (PRL) instead of GSM auto (PRL) <- edit - previously it mistakenly said GSM only the CDMA and WCDMA settings later to see what other effects there are.

Results for HTC Hero:

Your results will vary depending on the rom, but it should improve battery performance - some have had better results than me using this.

GSM only <---- If you don't get 3g with this it is the same as 2g setting then use GSM auto (PRL) if you want faster than 2g (as some people are getting 3g on GSM only - I will investigate. (if you don't use internet or don't need fast internet)
5½ Hrs - lost 5% Battery - This one is same as running 2g as you don't get HSDPA, but using Opera browser makes browsing fast even using this. If you want Higher speed data use the one below.

GSM auto (PRL) <---- Recommended if you want High speed Internet and save battery
1:40am to 2:00pm (12hrs 20 mins) - lost 40% battery with moderate use a bit of surfing at HSDPA speeds, a few calls and messing with a few apps. Other people have had even better results than me though, so I might change my rom and try again. (I would usually about this amount of time I would have lost about 70-75% - and yes it was that ridiculous - I had to find something to stop this).


" WCDMA Only"
2:06pm to 11:37pm - (9hrs 31mins) lost 46% battery again moderate use and a reboot
This one might be useful if you live in a place that has low GSM signal like the chap in post #10 as it does give HSDPA - but this is only a suggestion as I cannot test it in Iceland. Anyway

" WCDMA preferred"
6:02am to 2:51pm - (8hr 49mins) lost 41% battery this time with less use that the WCDMA use and no reboots.

 

[miketlo]

I'll give it a try

 

[RogerPodacter]

i read the first page, what exactly does "PRL" stand for? and isnt this just using GSM-only? how is it able to use gsm but then switch to HSDPA (3g) for data? i didnt think that was possible.

 

[masse1369]

I have been doing that for a long time and I'm pretty sure it helps...

Just set it to WCDMA only and you are all set...

 

[RogerPodacter]

well I think this really might help. I changed it to gsm auto (PRL) and my phone still uses 3g and my battery only dropped 2% in an hour and 10 min. went from 86 to 84% which it used to drop like 6% in That same time period.

I have to do more testing though to really know for sure.

 

[apolloms]

mine was on WCDMA preferred....will i lose anything by switching to GSM AUTO (PRL)?

 

[veldargk]

Giving this a whirl. When I'm at home and at work I'm on wifi which, combined, is like 90% of the time the phone is running so not sure how much it will affect me, but lets see

Jim

 

[RogerPodacter]

mine was on WCDMA preferred....will i lose anything by switching to GSM AUTO (PRL)?

you won't lose anything from my testing so far. full 3g still works and my data speeds are over 1.5 Mbps.

my theory is that this stops our phone from constantly searching for a roaming partner/network. if true ATT has no roaming agreements so who cares.

 

[apolloms]

you won't lose anything from my testing so far. full 3g still works and my data speeds are over 1.5 Mbps.

my theory is that this stops our phone from constantly searching for a roaming partner/network. if true ATT has no roaming agreements so who cares.

it seemed to not allow me to download anything from the app market

edit: it just takes a long time now

 

[miketlo]

it seemed to not allow me to download anything from the app market

edit: it just takes a long time now

I had that problem too but i wasnt sure if it was just where i was

 

[GarJones27]

Just set to GSM AUTO (PRL) and reboot.

I downloaded two apps from the market and both downloaded faster than usual. Also the browser seems to load faster.

I'll report back with battery data.

 

[GlenH]

It may be that this saves battery by using the PRL acquisition and system tables for allowed frequency + system lists, thus stopping the phone from searching all the time.

I've not had it on this setting very long so I can't really tell yet, but it looks encouraging so far...

 

[RogerPodacter]

i still am testing, but i have definitely noticed a MAJOR improvement so far. for example this morning my phoen has been off the charger for 4 hours, and i'm still above 90%. on normal days, my phone would have dropped much more than this.

and the battery voltage seems to be staying constant too. for example my batter was at 4040 mV, and i checked an hour later, and it was still at 4040 mV. this NEVER happened before, it would always drop some amount.

is it possible that this entire time our phones have been actively searching and updating the roaming list, but with this setting now its just locked on the home network and not searching anymore?

 

[Drakknar]

i still am testing, but i have definitely noticed a MAJOR improvement so far.

I can confirm that. My phone seems to use much less power while in standby mode and it just dropped from 99% to 89% in 7 hrs, with auto synching of Gmail, Facebook and other stuff, while in the last days I could experience drops of 10% in about 1.5/2 hrs. I'll keep testing this mode and will post back if I'll have something interesting to share

Thanks for sharing the trick mate!

 

[RogerPodacter]

I can confirm that. My phone seems to use much less power while in standby mode and it just dropped from 99% to 89% in 7 hrs, with auto synching of Gmail, Facebook and other stuff, while in the last days I could experience drops of 10% in about 1.5/2 hrs. I'll keep testing this mode and will post back if I'll have something interesting to share

Thanks for sharing the trick mate!

exactly my usage pattern, and my battery used to drop the same amount as you.

i used to kill 10% in an hour EASILY, sometimes more if i used the phone hear and there. but now with this setting, i'm now at 7.5 hours, and way more than half battery left still. on normal days my battery would be dead in 6 hours sometimes. huge improvement.

 

[Macmee]

I am not with a GSM carrier. Would I click CDMA?

 

[RogerPodacter]

I am not with a GSM carrier. Would I click CDMA?

i think the other thread said for CDMA users, you pick CDMA Auto (PRL). you should probably read the linked thread to be sure.

 

[Clarkster]

I am not with a GSM carrier. Would I click CDMA?

I didn't think there was a CDMA version of the Nexus out, just the two GSM versions.

 

[Macmee]

well the CDMA option didn't do anything and gave me no service sadly.

 

[Clarkster]

well the CDMA option didn't do anything and gave me no service sadly.

Well, that's because you aren't on a CDMA carrier then. I checked and the Nexus One only comes in GSM. If this is a Nexus One you have, then you are have a GSM version, and are on a GSM carrier.

Um, surprise!