My Note 2 battery is driving me insane.

I have been using my Note 2 for like 2 months. And I had been following the recharging cycle where you only charge the battery when it reaches 5% or less and remove from socket when it reaches 100%. This method has been working real well for me. I used to get really good battery life. I would recharge it to 100 and remove from socket and keep it there. I might only start working with it after 2 hrs of idle time a nd the battery percentage would be like 98 which is pretty normal.

But two days back when I had to go out I found my battery level at 24 % and since I had no other choice I had to recharge it for 10 mins. That's when the problem started. After coming back home the battery had pretty decent juice left in it and I left it idle. After an hour or two when I checked the phone it had already switched off. I was in shock and tried to switch it on but it didn't work. So I thought of charging it to 100. After almost 3 hrs it was fully charged but since I don't work on my phone so late in the night, I removed it from socket, switched it on and left it there idle. And when I woke up after 5 hrs it had only 69% juice left in my battery. I checked my running apps and there were none. I had my data connection stopped. And still only 69?

Thats kinda weird right? Is it because I recharged it before getting to 5 %. Is there a way I can remove the battery cycle cache or something?

  • 1
    First: LiIo batteries don't like it very much to run "low on fuel". What you describe as "charging cycle" rather is a "calibration", and should not be done too often: it shortens the battery's life time. It's rather recommended to charge as often as possible, keeping "fuel" at 50% or above if possible, and better not drop below 20% if you can help it. Second, I'd check for consumers like John's answer suggests; might be there's a rogue app. Third: Don't use task killers as John suggests; they often have rather the opposite effect. – Izzy Apr 28 '13 at 9:32
  • Yeah you've basically been fed lies about how to treat your battery. Running it all the way down to 5 percent every time is one of the worst things you can do to it. It will kill the battery faster. That said, it should still last for a couple hundred charges this way providing you don't leave it that far discharged for very long. – thomasrutter Jul 24 '13 at 16:30
  • @thomasrutter Can you suggest me the best ways to treat my battery, like when should i recharge it and all?? – user1474157 Jul 25 '13 at 18:22
  • That's technically a separate question so you should search for existing questions and ask your own. But I can say, top it up when you get a chance and it's convenient, and try not to get it too close to fully discharged too often. Li-Ion batteries are extremely easy and forgiving and you can treat them how you like for the most part, the one exception being avoid fully (or near-fully) discharging them every time. – thomasrutter Jul 26 '13 at 1:02

Since your device is pretty new there is almost no way it is actually the battery (unless it is a defective battery). It is probably a rogue application. Try turning off your device and turning it back on. You should try to reboot your device at least once a week, it will clean up any memory leaks and will help keep system applications from crashing. If restarting doesn't help, then let the battery die all of the way; then, let the device charge all the way before turning it on. If you are still having problems then it is either a system app that is getting hung up on something and hogging cpu, or it is a defective battery.

You can check how much battery each application is sucking up by going to:

Settings --> Battery Information --> Battery Use

That is where it is on my phone at least, it should be in a similar location for you as well.

In the case of a defective battery, as long as you haven't tampered with the device at all, it is covered under your warranty with the manufacturer. Just bring it back to your mobile carrier store and they should be able to handle it for you with no problems.


You can use a task killer to kill a rogue process on android. A rogue process could eat up battery especially if it is doing things like using Wifi.

I had this one development phone that I would charge, and then it would be in my pocket and it would start burning my leg because it would get so hot. It was a rogue system app that was constantly getting stuck in some sort of network loop whenever I was connected to wifi. I usually just restarted my phone, but I would on occasion just kill it with a task manager.

Here is (in my opinion) the best task killer on the market (for free): Memory Booster - RAM Optimizer

A restart about once a week will keep your phone functioning correctly. This will also clean up any possible memory leaks as well.

You should NOT use a task killer to end an app that is not hogging CPU, android should take care of all of that stuff for you.

Friends don't let other friends use Task Killers.

  • 3
    John, using task-killers in most cases rather has the opposite effect: they kill all apps, and 75% of them immediately restart themselves. Thus you use even more juice. Task and RAM management should be left to the Android system itself. Task-killers have their purpose, too: to kill a rogue app which e.g. is just eating all your ressources (90% CPU, too much RAM, and maybe even "downloading the entire internet") and can't be closed otherwise. Don't use them in "Chuck-Norris-mode" :) – Izzy Apr 28 '13 at 9:39
  • @Izzy will the android system be able to recognize that a system process has gone rouge? Will it be able to then terminate the app? I haven't heard of the android system being able to do such but I wouldn't be surprised if it were true. – John May 1 '13 at 20:41
  • In your comment you describe where task killers should be used. Your answer, however, sounds like you do a "Chuck-Norris-Roundhouse-Kick" to "clean up your running applications" -- hence the warning :) Maybe you want to update your answer and elaborate a little more on the "real good use" (and warn of Chuck)? Also, from the app's description I find some good points -- but it doesn't tell if a boost includes killing some non-whitelisted apps, and if so, on what criteria. Especially I cannot see how it detects "rogue apps", and neither have heard Android does that itself. – Izzy May 1 '13 at 20:55
  • 1
    @Izzy see edit, it you would like to add anything or change it just go for it I don't mind. – John May 1 '13 at 21:05
  • I like the final quote :) Yeah, that hits the nail with the task killers :) I just wonder why you removed that app-link. That Memory-booster sounded promising (finding and clearing memory leaks and the like)... – Izzy May 1 '13 at 21:24

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