[EVO 4G Q&A, Help & Troubleshooting] Biofall:
Over the months I have been an Evo user, I have collected some valuable information that all users should probably know in regards to maximizing battery life. Besides the stuff about 4G and a few specific options, these steps apply to pretty much any other android phone running 2.2, and a lot of them apply to versions below Froyo.

General Lithium Ion Battery Information

^^This link includes stuff about charging, including trickle charging aka SBC (Why NOT to use it, or at your own peril)

My tips for good battery life:

Tips for Non-Rooted users:

1.	Turn off all radios when not in use.

(gps, Bluetooth, wifi, data, 4g) Use a widget like the default HTC power widget or Switchpro from the market. The radios of the phone draw power if on even if the user isn't actually utilizing the radio's functions.

To manually turn off radios without a toggle, go to menu>settings>wireless & networks.

Wifi uses less battery than 3G, so use wifi when you can.

**IMPORTANT DISCOVERY**When you turn on your 4G radio, then turn it off, it will keep scanning and turning off all by itself.

The problem is apparently exacerbated by a 4G toggle widget, which causes the phone to automatically turn on 4G at boot. This repeating of scanning and disconnecting severely drains battery life, and sadly, no matter what ROM or kernel you use, there is only one way to fix it:

-If you don’t use the toggle widget, then you have to reboot your phone after turning off 4G

-If you do use a toggle widget, then you have to remove the widget from your homescreens, then turn off 4G via settings, then reboot.

**To check to see if this is happening, download alogcat off of the market. Look for the lines saying: I/Wimax ( xxx): <DC> Try to establish a connection to DC server.

E/Wimax ( xxx): <DC CONNECT> IO error: msg=’/xxx.x.x.x:xxxx –

Connection refused’

Over and over again.

2. Juice Defender is one of my favorite apps. Basically it controls your data for you to maximize life.

More explanations are on their page, search it on the market for free, or upgrade for more features.

Here are my settings for it: Click me

Note that for me at least, juice defender likes to deny apps data privileges whether you allow them or not, so screen on = data on works best for me.

3. I love live wallpapers, and I’ve always been a fan of pixel zombies, but they are really only good for showing off due to their battery drain.

4. Go to menu<settings<wireless & networks<mobile networks<disable always on mobile data.

5. Set your screen timeout to something that fits you

This will prevent your phone from staying on when you don’t manually turn off the screen. Also with this, manually turn off your screen when you’re done with your phone.

6. Everyone has that issue where the first ten percent go the fastest.

This is due to two things. One is that these types of batteries stop charging once they get to 100% to prevent damage, and begin charging again at 90%. This means that you could potentially unplug your seemingly fully charged phone at 90% actual charge. The second is number 7.5.

6.5. Use the trick described in this thread, it works.

My idea behind how often you should do it is once a month, if you flash a new ROM, or if you stop noticing the benefits.

This is the calibration technique recommended by HTC themselves. Check it out!​

7. Task killers used to be the shiz, but no longer.

Here is the ultimate, in depth, graphically assisted, explanation by the famous Fresh ROM's chef, Flipz. Shortly, in light of recent testing, really don’t do anything but force apps that the android OS needed to be open, and thus didn’t close, to re-open. So try not using them, unless for stuff like trying to figure out why your phone isn’t sleeping with system panel. You really won’t notice a performance difference, and the adverse effects you aren’t seeing will stop :P

+=+ A good alternative is the application SystemPanel Pro. It has a free version, but I highly reccomend purchasing the paid app. It basically monitors everything going on with your phone's usage both in real time an in terms of usage history. If your battery is draiging fast, it tells you what app was doing it, how much it was doing it, and allows you to stop it.

8. People posting screenshots of the Battery screen as proof of long lasting battery are giving statistically irrelevant information.

See HERE That screen shows time since last REBOOT, not last charge. This isn't always the case, but a lot of people will post a lot of things about battery life, but look for definitive screenshots and testing results before you break down and cry due to the poster's life and yours.

9. I'm sure you have all heard around that your phone isn't "sleeping".

This is referring to the phone's "awake" time, hence the name. When you go to menu>settings>about phone>battery, you can compare the two numbers, "up time" vs. "awake time." Generally, up time refers to the amount of time since the last reboot. The "awake time" is how long the screen has been active. The problem is, a lot of the time, due to the endless possibilities of inconsistencies between apps/ROMs/kernels/phones, the phone will not go to "sleep", drawing power proportionate to the screen being in use when it reality the phone is sitting idle.

If you compare these numbers, and they are the same, or if you note the difference, turn off the screen for a minute, then re-check and they are the same, then your phone is not sleeping.

One solution is to reboot.

Usually, SystemPanel will show an app that has gone "rouge" and is keeping your phone awake.

Uninstall applications/reinstalling them slowly, checking after every install to see what is causing it is one tedious but surefire solution.

Lastly,

Follow these steps that I have discovered almost always work.

1. Reboot phone.

2. Instantly upon reboot, as soon as you gain control, open up some type of monitor/taskkiller

3. "kill all" tasks on startup; about 5 times in quick succession should do the trick.

4. Turn off the screen and leave it for about five minutes.

5. Check the up time v. awake time and see if they are the same.

6. If they are, repeat steps 1-5. If they are different, you are good.

Tips for Rooted users:

1. Try out custom kernels.

By going to the EVO 4G Android Development section of the forums, you can see all of the different kernels being developed. These allow for all kinds of modifications like underclocking the CPU and undervolting, both of which save battery. To see how to use them, read the FAQ's in each thread's OPs.

Here is a great guide to custom kernel's by mroneeyedboh.

2. Use SetCPU in compliance with whatever your custom kernel allows.

This site will explain the basics of SetCPU: http://www.pokedev.com/setcpu/

-Profiles from SetCPU should usually involve these for battery life optimization:

-Screen off at the minimum clock speed for both, with the max raised on level if sluggishness is apparent

-A temperature greater than “X”

-General power related profiles that lower cpu speed at lower battery levels

-Here are my SetCPU profiles: 1 ,	2 ,	3

-My profiles change a lot as time goes by, because different kernel creators recommend different settings. I suggest reading up on whatever kernel you are using to gather settings.

------------------------------------------------------------------------------------------------------

NOTES:

*Some apps or processes begin to run at startup and keep the phone awake. These apps are not detected by things like spare parts or system panel, unless sometimes represented in the "system" process, in which case its usage will be unusually high.

This shouldn't take more than three repeats, and if it does, you need to factory reset, and slowly add apps back to see what's causing the problem.

___--- When it comes to actually "calibrating" one's battery, there are a couple of methods floating around. The method I first learned is to charge the phone all the way, boot into recovery immediately, and "wipe battery stats". Then reboot quickly, and run your phone all the way to death without charging it, then charge it all the way without interrupting it, and you should be good to go. Do this when changing ROMs/kernels for best results.

----When it comes to people claiming 20 plus hours of moderate/heavy use out of their current setup or other ridiculous absurdities, consider my position: No matter what you do, the Evo battery is the Evo battery. You can tweak it and customize it with kernels, ROMs, and settings, but none of that will turn it into a car battery. The main problem (besides a false sense of pride) that leads to these reports is the misunderstanding of what the usage levels are, so here’s my best summary:

* *Light usage – Phone screen actually on for maybe 4 hours. Things like a few texts, some emails, 20 minutes web browsing, etc.

* *Moderate usage – You watched a few youtube videos or similar apps, sustained web browsing, hundreds of texts, some games. Hours range from about 5-10 of screen on

* *Heavy usage – LOTS of video watching and games, or some high def gaming/movie watching for at least an hour to an hour and a half in total, with lots of emails and texts, browsing, and other app shenanigans

*I’m sure everyone doesn’t agree with all these numbers, but this is most likely a good average of what powerusers think. All specific hourage may vary due to differences in phones, batteries, ROMs, and kernels… Which also means that most battery comparisons are pointless; it’s only what you can improve on that counts!

I’ll update this whenever I see good stuff, people remind me, or I remember/come across things I do.

Hope it helps everybody!

Hit the "THANKS" button if I help you!

*All this is available in the link in my signature