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Help Stock kernal battery drain

lilnono93

Newbie
Nov 29, 2012
18
4
I got my VM GS2 4G the first weekend it came out. I liked the advertised battery life, but quickly realized that my phone suffered from heavy battery drain as many of them do. I will post my observations and notes for others to compare and learn from:

-First 3 or 4 days, couldn't go a full day of my normal use (which is not heavy) without plugging in.

-Using the GSam battery monitor app, I noticed that the Andorid OS and the kernal were accountable for more than 60% of total battery useage.

-Tried the factory reset and the 'leave the battery out for 5 minutes' tricks. Neither had any effect.

The problem slowly got better and in about a week, I was able to go to bed with about 10% battery left so I decided to be patient and hope that rooting and flashing a new kernal/ROM would fix the problem rather than trying to replace the phone.

In the 3 weeks since, I have noticed significant improvement (trend seems to be exponential by my estimate). I now go to bed with almost 60% battery remaining, though the kernal still accounts for 35% of the battery drain while the Android system (different label from Android OS) and Core Applications still take large chunks. Phone is still factory stock.

I plan to root it in the next few days using the Agat's One-Click Kernal found here. I will monitor battery useage and post back.
 
I've read booting into recovery and doing a wipe of the partition cache will have the same benefits as a factory reset. If that works, it's certainly easier to recover from.

There's a market app call betterbatterystats that does a fairly good job at looking for apps/services that are hanging the wakelocks.

From what I can see, my phone will enter deep sleep and become quite efficient, however when I'm using it (as stated above) the Android OS and display are battery intensive (I drain at about a rate of 15% and hour).
 
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My battery drain seems to be pretty high. Right now my phone has been on for 5h 14 mins and it is at 50%. The screen accounts for 55% of battery usage but android OS accounts for 21%. I had the problem before where android OS has been taking a lot of battery and had to factory reset to fix it, but it seems to have come back. Does anyone know a way of fixing this that doesn't require factory reset? Looking around on the internet it seems to be a common problem with ICS users.
 
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I'll post the link tomorrow, but set WI fi to never sleep, get juice defender or some other battery manager.I went from OS at 40+% to 4%. Some kinda ics bug. I think if you go the jd route it needs to be the paid version.

JD has some nice screen/keyboard lock control features under "Advanced" controls. It allows me to leave my PIN lock screen enabled without it activating when I'm connected to my network. If I'm out of the house it will wait an minute (or as specified) before locking the screen.

I didn't feel the app actually improved my battery life on the Triumph and the time it took to reconnect to my wireless (not JD's fault) was frustrating. However, it may be a more suitable app for the S2. I'm giving it another try. The latest version of the app seems a bit "smarter" with how it manages WIFI/data connections. Sort of "optimistic" that you'll need the data connections, but will turn them back off if they are not used.
 
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http://androidforums.com/samsung-ga...-galaxy-s2-battery-drain-fix-work-around.html

This is the link, It seems to work for me. This thing still sucks battery (screen) when you use it a lot, but now it isn't dropping to 40% in 3 hrs just sitting on my desk. I also killed all the syncing except for gmail. You really don't need facebook updating your contact pics every 15 min., and you still get all your notifications. My os is down to 4-7 %, where it was in the upper 40's
 
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Nice to know I'm not the only one.

I rooted with the Agat One-Click a couple days ago, but it didn't seem to help with the battery life. Mine seems to have leveled out, but at least it's at an acceptable level for me. Normally I can get through a full day with about 30% left, but I've had a couple days where I run right down to the wire. Kernel useage still takes up about 35-40%, screen about 20-25% and nothing else much over 5%.

On the plus side, I have noticed that this thing charges crazy fast, though. I'll get up and check it sometimes through the night and it probably charges faster than 30% per hour. That's a good enough trade for me for now, though hopefully we get a couple of nice custom ROMs/kernals that make better use of power.
 
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when I unplug my phone after charging it, the battery goes down to 99%. Other than that, I really haven't had any problems with the battery. What is causing this?

Probably a calibration issue. Try fully draining the battery and recharging fully 3 or 4 times.

I have a new S2 4G and it does the same thing. I wouldn't be worried about it. Think about how accurate the fuel gauge on your car is. (Plus - I'm an old retired electronics pro.)
 
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Probably a calibration issue. Try fully draining the battery and recharging fully 3 or 4 times.

Mine goes straight to 99% as soon as I unplug it too, though I'm more concerned about drain rate. I hadn't thought about calibration though, but done it with a few laptops. The process there is to fully charge the battery and allow it to drain completely without letting the comp sleep or hibernate. I'll try pretty much the same thing sometime, unless someone knows of a method designed for phones.
 
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