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My battery life just got about 10x better.

xephyr417

Newbie
When i first got my phone i used it like i wanted to. Data on all the time, constant texting etc... But the battery would literally be dead in 6 hours.

Then i became more aware of things. Mobile data doesn't have to be on for you to receive text messages and it can be switched on (wifi as well) in all of 4 seconds with power control. That saved me a lot of battery. I could get almost 8 hours now.

But it gets better, i recently rooted my phone and installed setCPU and have it set to underclock my phone when the screen is off. This increased the battery greatly... IMMENSELY. I could get home around 6 oclock with a solid 40% of battery left. However, there was still the 10% drop after taking the phone of the charger.

However, i found this http://androidforums.com/evo-4g-all...erior-battery-charging-4-18v-off-charger.html using this kernel, my battery life was amazing. I got home at 6 oclock today with 75% left. It even stayed at 100% for over an hour.

It really makes me think that the battery on the EVO isnt that bad if you know how to manage it.

So for those wanting to try it just
  1. Turn of mobile data when not using it
  2. use SetCPU to underclock the processor when the screen is off
  3. Download the SBC Kernel's. They work.

lovin my phone
 
SetCPU is great. My question is, will I get even better battery life if I limit the speed of the processor while the screen is on? Let's say I cap it at approximately 600 mhz all the time for except when its charging. Will the phone use less juice while I'm using it?
 
When i first got my phone i used it like i wanted to. Data on all the time, constant texting etc... But the battery would literally be dead in 6 hours.

Then i became more aware of things. Mobile data doesn't have to be on for you to receive text messages and it can be switched on (wifi as well) in all of 4 seconds with power control. That saved me a lot of battery. I could get almost 8 hours now.

But it gets better, i recently rooted my phone and installed setCPU and have it set to underclock my phone when the screen is off. This increased the battery greatly... IMMENSELY. I could get home around 6 oclock with a solid 40% of battery left. However, there was still the 10% drop after taking the phone of the charger.

However, i found this http://androidforums.com/evo-4g-all...erior-battery-charging-4-18v-off-charger.html using this kernel, my battery life was amazing. I got home at 6 oclock today with 75% left. It even stayed at 100% for over an hour.

It really makes me think that the battery on the EVO isnt that bad if you know how to manage it.

So for those wanting to try it just
  1. Turn of mobile data when not using it
  2. use SetCPU to underclock the processor when the screen is off
  3. Download the SBC Kernel's. They work.

lovin my phone

Thanks for the post, I was just about to ask for help with my crappppppy battery. I am rooted with myns rl5 and my battery between 5 and 10% within a minute of me taking my phone off the charger in the morn. And after checking email it drops down to the mid 80's. Its so horrible. But I am about to try this out and see what the result is. Fingers are crossed.
 
Ok, Im having a hard time installing the apk. It is in the root of my sd card and and when I open it it asks if i want to install the app and then it starts to load and then quits and says failed to download. Any idea what is wrong or what am i doing wrong? By the way its the wimax indicator.


Update: OK, I got this figured out. Uninstalled the old wimax version and then installed the updated version and all is well.
 
Why would you people want to install a Kernal that turns your phone into a time bomb? Have you seen what a Lithium battery in thermal runaway does?
 
we have been over this numerous numerous times. if you haven't read the threads, and seen the proof then please don't stir it all up over and over again lol.

i don't doubt some people played with some kernels they shouldn't have, or tried to hack and tweak custom kernels and thus could have possibly caused damage to their phones by pushing the limits....but there has been nothing proof that these sbc kernels by known devs are working and working well.
 
Well I flashed this kernel last night and did see a slight increase this morning. Instead of my battery instantly losing 5 to 10% of its charge it took about 10 minutes for the charge to drop 5% while I was checking emails. But how in the world are you guys getting the performance you guys are stating? Having 100% battery life for 1 - 2 hours after taking off the charger? I installed the Setcpu also and have no idea what I should have all the triggers and profiles set to. Please fill me in about this, and what the hell should I be looking for as far as things that could be sucking the life out of my battery. This is frustrating, I just want to be able to go throughout my day with out having my phone plugged in to the constantly. I'm not a heavy user at all, send texts mostly and hardly any calls and very little web browsing. I am connected to wifi all day though and 4g is off. Please help me. I love this phone, but this battery is crap.
 
SetCPU is great. My question is, will I get even better battery life if I limit the speed of the processor while the screen is on? Let's say I cap it at approximately 600 mhz all the time for except when its charging. Will the phone use less juice while I'm using it?

Sure, but it's going to be really choppy. Try it and see. I've heard reports that most people can underclock to around 800 MHz before seeing a real hit to performance. Of course, it's going to be really bad if you try doing that and using anything that requires a lot of system resources.

Well I flashed this kernel last night and did see a slight increase this morning. Instead of my battery instantly losing 5 to 10% of its charge it took about 10 minutes for the charge to drop 5% while I was checking emails. But how in the world are you guys getting the performance you guys are stating? Having 100% battery life for 1 - 2 hours after taking off the charger? I installed the Setcpu also and have no idea what I should have all the triggers and profiles set to. Please fill me in about this, and what the hell should I be looking for as far as things that could be sucking the life out of my battery. This is frustrating, I just want to be able to go throughout my day with out having my phone plugged in to the constantly. I'm not a heavy user at all, send texts mostly and hardly any calls and very little web browsing. I am connected to wifi all day though and 4g is off. Please help me. I love this phone, but this battery is crap.

1) Read the thread linked to above. Did you install the battery monitor widget to see if the kernel is actually working? All the information you need is in that thread, so I won't give details here.
2) How long did you leave it on the charger? This kernel isn't going to make a single difference if you pull it off the charger right when it hits 100%.
3) A lot of those people that are keeping 100% for hours aren't actually using the phone the whole time. It probably includes a good deal of sleep time.
4) Setcpu - http://androidforums.com/evo-4g-all-things-root/210253-setcpu-guide.html - let me know if you want more specific details on governor choice, etc. There are many, many threads discussing it.
5) Install spare parts to see what is using your battery. The most likely culprit are things that keep your phone awake. You can check partial wake usage since last unplugged after having your phone off the charger for several hours.
 
2) How long did you leave it on the charger? This kernel isn't going to make a single difference if you pull it off the charger right when it hits 100%.
3) A lot of those people that are keeping 100% for hours aren't actually using the phone the whole time. It probably includes a good deal of sleep time

Ok well let respond to these 2 points first.

I left it on the charger overnight as I do everynight so it had significant amount of sleep time. Now Im at 84% with minimal use, took off the charger about 1 and half hours ago. I'm in the process of looking into your other points.
 
Ok well let respond to these 2 points first.

I left it on the charger overnight as I do everynight so it had significant amount of sleep time. Now Im at 84% with minimal use, took off the charger about 1 and half hours ago. I'm in the process of looking into your other points.

Yeah, that seems kind of abnormal if you're not using it much. Go ahead and check spare parts.
 
What is the kernel that is supposed to be installed from the link above. I went to the link above and downloaded the HTC Kernel #15 V7 kermnel. And flashed it t my phone, but when I look at the actual info of the kernel in my phone is says i have 2.6.32.17 root@paris-laptop #2 installed. Is this the kernel? I downloaded straight from the xda website so it should be.

Edit: I just checked the zip folder that was downloaded and it says sbc htc 15. Just making sure the right kernel got flashed.
 
Yep, that's the right one. It shows up with that information under software information for whatever reason. That is definitely correct, though. You should definitely use the battery widget to make sure it's actually working, though.
 
Go to battery history, then select "partial wake usage" for the top drop down and leave the second drop down at "since last unplugged". You will be given a list of apps that have held wake locks in order of apps that held them the longest. For this to be of any use, you need to have had your phone off the charger for a few hours. Let me know what you see.
 
Go to battery history, then select "partial wake usage" for the top drop down and leave the second drop down at "since last unplugged". You will be given a list of apps that have held wake locks in order of apps that held them the longest. For this to be of any use, you need to have had your phone off the charger for a few hours. Let me know what you see.


Ive been off the charger since 8 am and my calendar is at the top which says total time: 1m 12s followed by the android system which says 1m 5s.
 
Ive been off the charger since 8 am and my calendar is at the top which says total time: 1m 12s followed by the android system which says 1m 5s.

yeah, that's not a problem at all. Mr. Ed just asked a good question as well. What is your PRI version?
 
Sorry for late reply.

Quite honestly, in getting battery life that good im not using my phone that much. I check texts between classes. Besides that everything is off, so for 50 min gaps my phone has essentially the same charge (thanks to all my tweaks)

As far as the Sploding Lithium Battery goes... **** I PROLLY SHOULDA LOOKED AT THAT. but im not freaking... hopefully it doesnt happen. But if there is even ONE example of an actual sploded battery im going back to original kernel fasho.
 
You can try downgrading to PRI 1.77. You can get it here:

[ Radios ][ 12-17 ] All EVO Radio, WiMAX, PRI, NV & HBoot versions - xda-developers

You flash it from recovery like any other update. See if that helps.


So I flashed the PRI yesterday and did my usual routine, charging my phone overnight and then taking it of the charger in the morning to check emails. Well in the half hour I have had it off the charger my battery had dropped down to 86%. And during that time I checked email and checked out these forums. Mind you I wasnt using the phone constantly for that whole 30 minutes. This sucks, my battery lasted twice as long unrooted. Any help from anyone would be greatly appreciated. Also, I checked spare parts and my the android system had the most usage ast 1m 19s if this means sheeting to someone. Thanks.
 
If you go to batt stats, then select cell standby, what does it show for your time without signal? Also, if you haven't done it yet, update your profile (menu->settings->system updates->update profile.
 
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