[GUIDE] The Total Newb's Guide to Wakelocks

PARTIAL WAKELOCKS

PWLs are a different beast. These are almost all caused by an app (with a couple of notable exceptions). For that reason, I won't go in-depth on too many of them, as the solution is usually to delete the app causing them. There are a few notable ones, and a few apps that merit mention.

AudioOut_1, AudioOut_2: This is an evil leech of a wakelock that will drain you dry if given the chance. For being such a pain in the app, it's surprisingly easy to get rid of. This wakelock is created whenever the phone's speaker plays a sound. With 99% of sounds, it goes away almost instantly. With keypad sounds, however, it doesn't go away so quickly, and it will sit there draining your battery for as long as it goes unnoticed.
To fix: Open Settings, then select sound. Turn off keytone sounds, touch sounds, screen lock sounds and vibrate on screen tap. It'll take some getting used to, but the extra battery you'll coax out just by solving this ridiculously simple problem is more than worth it. See DoctorQMM's post (#5), linked at the end of this one, for info on additional causes of this wakelock and how to fix them.

ConnectivityService: This will appear whenever your phone is trying to connect to a mobile data network. Excessive wakelocking here suggests that your phone is having a hard time finding a network, and an even harder time staying on it.
To fix: Test out different radios and see if one's better in your area. I personally have to use UCLF5, as UCLF6 is a mess out where I live. If you're able to control your radio bands and you don't live in an LTE area, setting your phone to hunt for GSM/HSPA connections only can save you a little bit of juice here. Not much, but every drop counts, and if you're not using LTE anyway...

AlarmManager: This isn't a wakelock unto itself so much as it's a compilation of app alarms and the time they held the device awake for. Seeing the wakelock alone doesn't tell you much, but here's where one of those features of BBS that I said we'd be using comes in.
To fix: Open BBS. Tap the menu button, then "More", then "Raw Alarms". That will show you which apps are waking up your phone, and how often they're doing so. Google will have a ton of wake-ups, but they're mostly innocuous. We'll discuss some of Google's problem apps later. Email clients will also have a ton of alarms. If anything else looks out of whack, though, first check the app settings to see how often it's refreshing. If the app is set to refresh every hour but it's set off 400 alarms in the last 30 minutes, get rid of that sucker and email the dev. You can't eliminate this wakelock, and it's constantly my #1 PWL at this point, but you can minimize it.
A special note about this wakelock: You will get all kinds of crazy numbers out of this wakelock. You may see as high as 20m on a 1h30m stretch of battery. You will want to kill this wakelock, and kill it with fire. Don't, I say, don't do it! Look at your deep sleep time vs. time awake - screen on. Odds are, it's far less than the 20m that this wakelock is showing. You may have a time awake - screen on time of less than 3 minutes. What's the reason for the discrepancy? Well, it's well-known that there are wakelocks out there, PWLs especially, that will hold your device awake even if it's already been woken up: i.e., you'll have a PWL registering while the screen is on. Alarms are certainly among those that do so, as they are designed to wake your device up, so that's the first thing they'll try and do. I suspect the remainder of the discrepancy is caused by the way BBS reports. I suspect every alarm is tallied differently, so that if you have two alarms go off at the same time and last for 2 minutes each, BBS will register 4m of wakelock even though it was only held awake for 2m. Make sense? It doesn't for me either, but that's the best pair of explanations I've got, and the numbers seem to back it up.

MediaScannerService: This is a wakelock created by the system as it scans your device for music, movies, pictures, etc. Once in a while, it will randomly get hung up and hold the phone at 384 MHz for...well...until you notice and do something about it. Like AudioOut_1, this is a heavy-drain wakelock. Luckily, like AudioOut_1, it's almost always easy to fix. A note about this wakelock: it's been shown to be an occasional, but serious, problem on Jellybean ROMs. We're still not entirely sure why, let alone how to solve it permanently. That said, haloeight has been able to beat it into submission on his phone.
To fix: Reboot. Ninety-nine times or so out of a hundred, this solves the problem. If the problem persists, go to Settings -> Applications -> Running then tap on "Show cached processes". Find the Media process and stop it manually to kill the wakelock. That's a short-term fix, though, as a persistent wakelock from this process most likely means you have a corrupt media file somewhere on your phone--and there are a lot of sounds, movies and images on your phone. This is one of the few wakelocks that, if it's a regular problem, justifies considering a full wipe and clean reinstall. That's not because it's doing any kind of damage to your phone, but more because sifting through every single media file on your phone to find the culprit isn't really a practical solution. If you've got a persistent wakelock here on a JB ROM, try haloeight's approach above.

SyncLoopWakeLock: This is exactly what it sounds like; your phone is being held awake while apps sync. There are two possible causes for this: apps syncing (duh) and a bad data connection.
To fix: Open BBS. Tap the menu button, then "More", then "Raw Network Stats". This will show you which apps are using the most data, and help you narrow down possible culprits. Once you've done so, check those app settings and make sure they're not set to constantly push notifications, refresh every five minutes or anything dumb like that. If they're set correctly and still holding sync open that long, try downloading the Speed Test app off of the Play Store and test your phone's connection. If your connection is on the slow side, it's possible that the apps are struggling to sync because of your bad data connection. Try flashing different radios to see if that solves it. If the troublesome apps remain so after you've found a better radio, it's best to just delete or freeze them.

ActivityManager family: This is a harmless wakelock. The typical cause is not exiting out of apps fully before turning the screen off.
To fix: Don't sweat this one too much. If it's a big issue for you, make sure that you're exiting out of apps fully (i.e., either use the back button to exit the app or FC it in Task Manager) before turning the screen off. Credit to the XDA Wiki on this one, as this is one of the PWLs I wasn't able to figure out for myself simply because I hardly ever saw it. I use the back key to exit apps.

GTALK_ASYNC_CONN family: Despite its name, this wakelock doesn't seem to be directly related to Google Talk. How do I know? I haven't had Google Talk on this phone in over a month, but the wakelock still pops up from time to time. This wakelock also seems to be related to a poor wifi connection, so keep an eye on that as well. These wakelocks can be absolute destroyers of your battery if given the chance, and unfortunately, there's no known root cause for them, and no reliable way of eliminating them.
To fix: These wakelocks will often disappear within a minute or so of generating. If one becomes persistent, check your wifi/data connection and make sure it's good. If it persists, reboot into recovery and wipe cache and Dalvik ASAFP. That solves the problem temporarily, but it will reoccur. Thanks, Google.

NetworkLocationLocator: What a lovely name for such a lovely wakelock. It's a minor annoyance usually, nothing more. If this one is persistent, it's because you're in an area with crappy cell coverage and very few Google-mapped Wifi networks.
To fix: Why, exactly, are you leaving Network Location on all the time anyway?

NetworkLocationCallbackRunner: Thanks to clankfu and mw86 to pointing this one out, and a huge thanks to promiseofcake for finding the solution. This is the first wakelock published here that's specific to a phone other than the Skyrocket; it's an S3 issue. Hooray, we've gone global! NetworkLocationCallbackRunner is another wakelock caused by that most wonderful of apps, Google Maps. If you're still using it, seriously, why?
To fix: Upon turning on your phone, don't open Google Maps or anything else that utilizes Google location data. Or, you know, you could just uninstall Google Maps and use an alternative program...details below.

show keyguard: This is a new one for me. It had always been there, but since switching ROMs, it's really started to show up. Not in massive quantities, but enough to make me scratch my head. I've already established that setting your lockscreen to not show user info, weather or calendar data will significantly reduce this. I'll play around with adding those back in more, and having sliders on your default lockscreen won't do much damage either. Still, the more people who've goofed around with this one, the better, as it makes this entry all the more accurate.
To fix: I'm testing several possibilities now, but the one that's worked best so far is turning calendar, weather and user info off. It seems that having those on causes the lockscreen to wake the phone to refresh itself, which creates the wakelock. Judging by my recent experience, this seems to be a pretty big leech.

Chekin Service: Thanks to epapsiou for finding this one and confirming my guess on it. Getting tough to test without my Skyrocket being used as a phone anymore. This wakelock, while a Google Services process, seems to be caused by Facebook. That kind of confirms my theory that Facebook "borrows" Google services.
To fix: Uninstall Facebook and use an alternative app, or just access Facebook through your mobile browser of choice.

SCREEN_FROZEN: Uh oh.
To fix: If this is high on your list, you've got bigger problems than a wakelock.

PWL OFFENDING APPS

We're almost done, I promise!

Down here, I'm going to list off for you apps that will cause you severe PWL migraines, and what to do about them.

A note when uninstalling Google built-ins: Google built-ins are often system packages, and deleting them can have unpredictable results. I highly recommend freezing them in Titanium Backup for several days to see how the phone runs before uninstalling them through there as well. Deleting system processes is inherently risky, and I assume no responsibility for your own decisions.

Facebook: Any social networking app will want to sync as often as it can, but you can overrule that by setting notification intervals. Thing is, Facebook doesn't respect those intervals, and wakes up the device for data exchanges pretty constantly (even though your news feed may only update every hour or so when you want it to). This app is no better than bloat, and should be treated as such when you clean house.
Alternative App: Friendcaster and Fast are both great alternatives that let you set how often the app wakes up, but I've taken to just accessing m.facebook.com through the browser of my choice lately.

Gmail: A running theme here will be that if there's a non-Google equivalent to a Google app, you should probably kill the Google and download the alternative. Gmail is an alarm fiend, and one of the main offenders if you have an excessive SyncLoopWakeLock problem.
Alternative App: How many email clients are out there? I've had the best luck with the stock Email app, but K-9, Kaiten, MailDroid, even Enhanced Email and Touchdown for the power users are all great alternatives. Speaking of which...

Whatever email client you're using: Email clients will always be high up on the list of alarms, and that's by their nature. Keep an eye with raw network stats on how long they're connected for, and don't be afraid to experiment. I tried K-9, Kaiten and MailDroid before settling back on the stock Email app as the one that gave me the best balance of battery life and necessary features.
Alternative Apps: Download and try out different clients until you find the one that works for you. Nothing ventured, nothing gained, right?

Google Latitude: Latitude is a tracking service. As such, it tracks you. Beyond the creepiness aspect of that, it holds your phone awake pretty often while doing so. Kill it. Kill it with fire.
Alternative App: Personally, I'm not into the whole stalking thing, but I've heard that Glympse works quite well.

Google Maps: Colossal waste of space and battery. You can do better. An important note on Google Maps: this app will still wake your device up even after being frozen in Titanium Backup. I don't know how it happens, but it does. To truly solve the alarms from Google Maps, you have no choice but to uninstall it. Do so at your own risk.
Alternative Apps: I'm a fan of Waze for navigation and MapQuest for a Google Maps-ish browseable interface. OSMAnd is also a great alternative, but it uses a ton of internal memory because of its offline nature. If you really love Google Maps, reinstalling it from the Play Store as a user app can reduce those wakelocks dramatically.

Google Play Music & Movies: Updates itself constantly and wakelocks. Even if you freeze it, it still somehow manages to tell you that there's an update available. It's the Google zombie.
Alternative App: There are literally 100+ music and/or movie players out there. I'm sure you can find one that works for you. I'm a big fan of RocketPlayer for music, and I just use the stock video app more often than not.

JuiceDefender: What's that you say? JD sets off tons of alarms and holds the device awake for more time than I'd care to discuss, largely because of its data control settings. More harm than good, in my opinion.
Alternative Apps: JuiceDefender's main goal in life is to minimize the amount of time your device is held awake. Therefore, if you've just gone through all this to clear out wakelocks, do you really need another wakelock-prone app to do what you've already done?

Skype: Occasionally, after a call, Skype will wakelock. This is not designed to happen, and is more a glitch in the app than a forced sync. Force-stopping the app and clearing its cache have solved it for me on the rare occasion that I've seen the wakelock occur.
Alternative Apps: No idea. I don't personally consider this a "replace" situation.

World Weather Clock Widget: Do you have this on your phone? Get rid of it. I installed it as an alternative to SiMi Clock Widget, and while it certainly looks pretty, it ignored my "Update every 3 hours" and tried to update 275 times in that 3 hour window. This drove AlarmManager, GSYNC_ACONN, and NetworkStats off the deep end, and left me at 82% deep sleep with 6% of my battery gone in 3 hours. Kill it. Kill it with flaming nuclear waste.
Alternative Apps: I liked SiMi Clock and wanted to try something new, basically. I'm back to SiMi, but there are literally hundreds of clock widgets out there.

Google Search: If you use Google Now, forget trying to fix this one. GNow is a battery hog, and there's nothing you can do about it without crippling the feature. If you don't use GNow, you can use Greenify to hibernate Google Search and stop the persistent alarms and wakelocks it creates. Greenify is a method I hadn't used in the past, but I've grown to like it for hibernating rogue Google apps.
Alternative Apps: A quick look at the Play Store revealed Quick Search to be the second most-popular option after Google Search. I've run devices without Google Search in the past without issue, but it is usually a system app, so freezing instead of deleting would be a safer option.

That's the bulk of what I've learned from clearing out wakelocks. Remember how, early on, I specified that the search engine of your choice was the third tool? Simple fact is, I haven't installed every app on the planet, so I haven't seen every PWL out there. Because of the way my phone's set up, there are KWLs that I've never seen and never will. If you've got a pesky wakelock that won't go away and it's causing noticeable battery drain, Google (or Bing, or Ask.com, or whatever) is your friend. Good luck, happy hunting, and enjoy the extra battery life you'll get just by spending a few hours over the course of a few days tracking down and killing those wakelocks.

Also, be sure to check out Jrockttu's thread on fixing your battery, as there's tons of great information in there.

Additional in-thread references below. If any of these posts helped you out, please click the link down here and send them a thanks.
DoctorQMM covers com.google.android.apps.maps, an alternate fix for AudioOut_1 and using CPU Spy to help track down wakelocks.
kishke tracks down an alternative cause for the sdio family of wakelocks (including sdio_al) and details it for us here.
polarbearno shares their experience with the mmc_detect family of wakelocks.
haloeight gives us some great steps on how to get rid of the MediaScannerService wakelock on AOKP-based ROMs.
promiseofcake solves the S3-specific NetworkLocationCallbackRunner PWL.

A Comprehensive (but not by any means definitive) Guide to Wakelocks

OP edit, January 12, 2016: To say that I'm proud of what this guide grew into would be an understatement, given that drawing it up was a weekend project for me using my old Galaxy S2 Skyrocket and either ICS or JB.

Take that last little bit into account here. It was done over three years ago on an S2-variant phone using Android 4.0 or 4.1. A lot of the specifics here are no longer going to be 100% correct, even if the principles remain true. If you're a rookie de-wakelocking your phone for the first time ever, please take what you see in the OPs with a grain of salt and ask questions in the thread before making any drastic system changes or mucking around in a terminal emulator.

Thanks for stopping by, and I hope you know a little bit more about your phone when you're done here than you did coming in!
-TJ
----
Wakelocks suck. If you're trying to maximize your battery life, you know this already. Some wakelocks are happy, friendly things, but many are silent leeches, sucking away your battery life while you remain blissfully unaware of what's happening. The goal of this guide is to list some of the more common wakelocks you'll encounter and how to wipe them off of your system. As you encounter ones not on this guide, let me know and I'll add them to the list. For some reference, I typically have light to moderate use of my phone. Before de-wakelocking, I was getting maybe 24 hours on one charge. After de-wakelocking, I was up to 36. Then I bought the Galaxy Nexus Extended battery, and on that battery's third cycle, I went two and a half days on a single charge. Impressive, right?

First off, you have to understand the difference between kernel wakelocks (KWL) and partial wakelocks (PWL). KWLs are wakelocks caused at the kernel or hardware level. Some of these are benign, and some of them are vampires. The only way to solve them is to change how your phone behaves. You'll see examples of that below.

PWLs are wakelocks caused by an app. The solution to these, more often than not, is to freeze (or, in the case of Google apps, uninstall) the offending app. Before you do so, and this is critical, go in via Settings -> Apps, force close the app, and wipe its cache and data. If you don't, you'll almost certainly cause yourself more headaches about 30 seconds after killing the app.

Second, you need to know the tools involved in wakelock hunting. The first is Better Battery Stats. Google "better battery stats XDA" and the dev's post will come up; they give this app away to XDA members. That said, if BBS helps you out, show the dev some love and buy the paid version. It's only $2.89, and the dev will have more than earned it from you by the time you've finished de-wakelocking yourself. The other tools you'll need are (hopefully) this guide, and, of course, the Internet search engine of your choice. I won't cover everything simply because I haven't seen it all.

Two final notes before the guide: do not go wakelock hunting right after installing a new ROM or clean-wipe reinstalling your current one. New ROMs cause the phone to go nuts for a little while, as things decache and little behind-the-scenes tweaks are made. Wait one full battery cycle (100% to 0%, which you're probably doing to calibrate after a clean ROM install anyway) before trying this, or you'll drive yourself nuts. Also, remember that solving one wakelock will often create another, especially early in this process. That's normal and to be expected. God does not hate you, your ROM of choice is not crap, your phone is not glitched, and a clean install while your current ROM is still settling in will only make things worse.

So, how do you track these wakelocks down with BBS? This is a really complicated procedure, so make sure you're with me. First, open BBS. Then, see the dropdown menu at the top that probably says "Other" right now? Tap it, and then you'll see "Kernel Wakelocks" and "Partial Wakelocks" below. That was obscenely difficult, right?

Something to note with BBS: it seems to have a weird "counting" bug. While testing a ROM with BBS, I finally began to question why my PWL time would be considerably higher than my true wakelock time. "True wakelock time," simply put, is time awake - time awake with screen on. If your phone is awake for 45 minutes and the screen is on for 40, you have five minutes of true wakelock time.

So why does BBS say that you have 90 minutes of PWLs when you only have a true wakelock time of 45 minutes? Well, I have two theories to account for that. One, BBS counts wakelocks independently, even if they occur at the same time. For example, if AlarmManager wakes your phone up for two minutes and AudioOut_1 wakes your phone up for 30 seconds during that same time, BBS will register 2m30s of PWLs even though the device was only held awake for 2m total. Now throw 30s of wlan_rx_wake (KWL) in there, and BBS is registering 3 minutes of wakelocks when there were only two. Throw in the notion that you had the screen on for 30 seconds during that time frame, and suddenly you're showing 3m of wakelocks when really there was only 90 seconds of true wakelock time to begin with. BBS has effectively doubled the reported wakelock time, and thrown off your stats. Now, throw in several dozen mini-wakelocks happening at once with the screen on, and you can easily see, say, 6h of PWLs on a 24h run, even if your true wakelock time is only 45m. It seems that Android's battery screen in settings reports this the same way, so my advice to you is to use the true wakelock time when cleaning up and attack KWLs and rogue apps. Some PWLs (AlarmManager) will always be high.

The second theory is that alarms are given a minimum reporting duration; i.e., five seconds per alarm for the sake of demonstration. Now, let's say you have Facebook, Twitter, Google+, LinkedIn, Gmail, Email, News & Weather and BBC News all set to sync every 30 minutes. They'll each set off an alarm at the same time, and suddenly your five seconds of alarm reporting time becomes 40 seconds every half hour. Now, let's say you have 35 alarms going off every half hour (not out of the realm of possibility with Google Services Framework). 35 x 5 = 175 seconds of time awake (in the five seconds per alarm scenario), which is now 350 seconds per hour of wakelocks reported, even if the true wakelock time was only ten seconds. Just something else to keep in mind when attacking PWLs.

One more note on BBS and how it handles KWLs: There is no such thing as a 0-KWL cycle, regardless of what the BBS reporting screen says. If BBS is showing 0 KWLs, tap the menu button, then "More", then "Raw Kernel Wakelocks" to see them. KWLs are required to boot the phone. In essence, the only phone that has 0 KWLs since it was last charged is a phone that hasn't been turned on since its last charge.

There are a couple of other features of BBS that we'll make extensive use of later, but there's one you need to know right now. Tap your phone's menu button to get the BBS menu up. Tap on "More". See the button that says "Set Custom Ref."? You'll need it--you'll need it a lot.

Also, anytime new information about a certain wakelock or wakelock family comes to light elsewhere in the thread, I'll be sharing that information here. If it helps you out, please visit the post that gave us that information and thank the poster. I'll link to each post twice, once in the wakelock description and once at the bottom of the OP, so no excuses about not being able to find it!

Last, but certainly not least: modifying your system in any way, including altering or deleting processes needed to resolve wakelocks, can have unpredictable results. Use caution and make backups of your apps and data, as well as nandroid backups, frequently while finding and eliminating wakelocks. Any modifications you make are done at your own risk, and I assume no responsibility for any damage you may do to your phone while cleaning out wakelocks.

With that said, we'll get started with the KWLs, as they're the trickiest to get rid of. Use the guide below to identify your wakelock, what is causing it, and how to get rid of it.

KWLs in post #2
PWLs in post #3

KERNEL WAKELOCKS

wlan_rx, wlan_rx_wake, wlan_wake: This is a wakelock caused by network traffic. The easy solution would be to just turn off Wifi, but be careful doing so! If an app goes to sync and it sees that Wifi is off, it will search for a mobile data connection (which causes the ConnectivityService wakelock). If it can't find a mobile data connection, it will wait and search again at its next sync interval and/or automatically sync when the phone wakes up. This wakelock can also, deceptively, be caused by the Wifi network itself as it refreshes connections or refreshes IPs.
To fix: This is a tricky little sucker to fix, as there are so many possible causes for it. Airplane mode is a safe bet--syncing apps seem to "respect" airplane mode, whereas if Wifi alone is turned off, they'll just try to find a way around. But then, of course, you lose your ability to talk on the phone. If you're particularly unlucky, your Wifi network itself will be the problem. Mine was--between my wife and I, we have four computers, an iPad, three Androids, a Wii, a PS3 and a Wifi-enabled TV hooked into our home network. The "background noise" caused by all of that would wake my phone up constantly. The solution? I happened to have a spare Wifi router laying around, so I hooked it up, set it on a different channel from my main router, and we now use that network for two of our three smartphones. Period. It's not the easiest fix ever, but wlan_rx_wake is almost completely eliminated (I'm looking now and have 4m45s of it 12h27m into a charge).

PowerManagerService: This is probably your #1 or #2 kernel wakelock, and you'd probably love to get rid of it at all costs, right? Hate to say it, but there's not much that can be done about this one. PowerManagerService is a KWL that serves as a "catch-all" for your PWLs. It's a placeholder, nothing more, nothing less. Don't spend much time worrying about it.
To fix: Reduce PWLs. See below.

deleted_wake_locks: Remember what I said above about force-stopping an app and deleting its cache and data before uninstalling it? This wakelock is why. It's the PowerManagerService for deleted apps. Once the app is gone, the wakelocks it caused suddenly become unknown to the system, so they get lumped in here. This number can also go up as the system "looks for" deleted apps and/or finds more wakelocks associated with them, but not dramatically.
To fix: Make sure to force close apps and wipe their cache and data before deleting. A reboot should eliminate the wakelock entirely. If it's still showing up, wipe phone cache and Dalvik.

sdio_al, sdio_dmux, etc.: This is an annoying wakelock, as there are two potential causes for it. One's easy, and one sucks. The easy one is that you've fallen victim to the charger wakelock. The easiest way to tell is to download Jrockttu's Skyrocket Charger Test App. If your charger shows up as AC Regular Charge, there's your problem. If it's AC Fast Charge or USB Normal Charge, your wakelock could be caused by your SD card. That can be an irritating fix, but the SD card version of this wakelock is typically small enough that it's not worth addressing. Also, a huge thanks to kishke for discovering a third cause for the sdio family of wakelocks: data. It seems that the sdio family is also the wlan wakelock family equivalent for cell data, and can be caused by apps searching for a data connection.
To fix: Check your charger and adjust if needed. To test the cell data possibility, make note of the time on the sdio wakelock, then turn cell data and Wifi off and walk away for an hour. Check it upon your return, and if you have minimal to no sdio wakelock, that was it. Try out some different radios for a better connection, or leave cell data off and stick with Wifi only. If it's the SD card, it's probably not a strong enough wakelock to be worth fixing, but if you want to fix it, you'll have to format your SD card. If formatting doesn't work, format it again, then wipe cache and Dalvik.

alarm_rtc: This is your phone's internal alarm scheduler, set to wake up your phone for sync, push, etc. Closely related to the AlarmManager PWL.
To fix: Check your apps and make sure they're only set to sync when you want them to, not for constant push or stupid-short intervals.

mmc0_detect, mmc1_detect, mmc2_detect: I'll be honest, I have no idea what causes these. Fortunately, they seem to be minimal, so I've never wasted much time worrying about them. polarbearno, however, has had a great deal of experience with this wakelock, and traced the cause of excessive activity here to a faulty SD card.
To fix: Unmount your SD card and pull it, then reboot. Might want to clear cache and Dalvik for good measure. If your problem was caused by a faulty external SD, this should solve it. If your problem was not caused by a faulty external SD, we're back to the original solution of "good question".

vbus_present: This wakelock exists as long as the phone is plugged into a wall charger. This wakelock can also persist if you use an Apple-compatible charger, which registers as "slow USB" charging and will cause the wakelock to hold after you'e unplugged.
To fix: Check your phone. Is there a cord plugged into it? If so, does that cord lead to a source of power? If so, unplug your phone (after it's fully charged, of course). Is the wakelock still there? Plug your phone into an OEM charger for a few seconds, then unplug it to kill the wakelock, then consider ditching that piece of fruit you're charging with. I try to use OEM Samsung chargers as much as possible, as they're designed for the phone (and to not cause persistent wakelocks). Jrockttu has an awesome charger test app, linked to in the OP of his outstanding "fix your battery life" thread.

suspend_backoff: This is a difficult one to nail down. Very difficult. To make a very long story short, this wakelock is caused when your phone wants to sleep, but a running process blocks it from doing so. Typically, this is going to be Wifi. Make sure your Wifi is set to stay awake when the phone sleeps. Otherwise, you risk the Wifi going out of its way to keep the phone from sleeping. This can also, unfortunately, be caused by apps, making it hard to pin down.
To fix: Do the Wifi thing, then reboot into recovery and wipe your caches. If it persists after that, you have no choice but to look at a dmesg output to pin it down. Go into a terminal emulator app and type the following commands, one per line:

su
dmesg >/mnt/sdcard/dmesg.txt

Next, transfer the .txt file onto your computer and open in WordPad or a similar program that automatically cuts line (i.e., no Notepad). Search the document looking for the word "event". You should find a lot of strings that look like this:
eventX-XXXX
Where the X's are all numbers. See those last four numbers after the dash? You should see them repeated again and again. Write them down, then go back into your terminal emulator. They are your process ID (PID). Once there, type:

ps

This will show you all processes that have run since your last boot. If you look at the second column from the left hand side of the page, and you should see a sequence of four numbers. These are listed sequentially, lowest to highest, as you come down the page. Scroll around until you find the sequence of four numbers that matches the one you wrote down. The line below those four numbers is the name of the process causing the wakelock. If it's instantly recognizable as an app, delete the app and see what happens. If it's a hardware thing that can easily be fixed, like Wifi, change your settings to accommodate it. If it's com.android.process.acore, I smell a wipe in your future. If you don't know what the process is, don't go screwing with things to find out. You can brick your phone in terminal emulators. Instead, write it down and Google it. Someone has already written about what this process is and what it does. If it's something you can easily fix, go for it. If it's a deeply-embedded system process, I'd just do a full wipe and clean reinstall.

Remember, terminal emulators can brick your phone if you're not careful. If you use them and something bad happens, or if you wreck your phone trying to fix this or any other wakelock, it is your problem, not mine.

There are a number of other, lesser KWLs that I'm not going to worry about here because you shouldn't worry about them either. You might occasionally see a battery cycle with very low (sub-1%) KWLs, but that's the exception and not at all the rule.

PWLs in post #3

T.J. Bender: Good topic… good write-up. I can’t agree with you more regarding the frustration level chasing down “greased-pig” wakelocks! The key is to have the right tool-set for analysis. At a minimum, make sure you have CPU Spy, BBS, and a utility which will show you what processes and services are active. Here’s my approach to identify wakelock problems. Again using CPU Spy to check time in Deep Sleep.. and using BBS to check Count of Alarms as well as time (minutes/seconds) of wakelocks:

1) open BBS and set a “Custom Reference” point (basically, this will reset the clock)
2) open CPU Spy and “Reset Timers”
3) turn screen off and let it sit for your predetermined time (i.e., 15min, 30min, 60min, etc)
4) when you reach the first predetermined time checkpoint, turn screen on and first check CPU Spy. How much time did the phone NOT sleep?
5) open BBS and check “Partial Wakelocks” against “Custom Ref Point”. Also check “Alarms” against “Custom Ref Point”.
6) do this every predetermined time (i.e., 15/30/60 min).. and write down results

What I found was very interesting. First I found "com.google.android.apps.maps" Partial Wakelocks were running about 80 times an hour (and preventing Deep Sleep): SOLUTION (thanks Bruno2123), un-check "Google Location Service” in "Location Services" in system setup.

Second culprit: AudioOut_1 : I also had unchecked all the keytone and touch sound options in setup, however, I was still getting a boat-load of PWL for AudioOut_1. I tracked it down (trial-and-error) to PowerAmp. Even though PowerAmp was not actively running, I had checkmarks (in PowerAmp Settings… Headset) in “Pause on Headset Disconnect” and “Resume on Headset Connect”.. which were preventing Deep Sleep. By un-checking these, it stopped the PowerAmp AudioOut_1 PWLs… and allowed Deep Sleep.

Third: this was a surprising find. Started to continue to see excessive AudioOut_1 PWL times; however, fewer counts (number of occurrences). Turns out, every time I open PlayStore, AudioOut_1 PWLs incremented… every time I played certain games (even with sound turned OFF in the game’s settings), AudioOut_1 PWLs incremented. However, these did not interfere with Deep Sleep.. these PWLs incremented when screen was on anyway!

Anyway, hope others find this approach useful and hopefully will help you identify PWL/ Alarm problems and find solutions.

mmc2_detect

I have a Galaxy S GT-I9000 with semaphore kernel and ICS333 ROM. This combination has given me great batterylife and great performance. However after months of use the battery suddenly started to drain from 100% to 0% in about 12 hours. BBS (BetterBatteryStats app) told me that this was caused by a kernel wakelock called mmc2_detect. This thread was the closest I came to finding out what the process does, i.e. no clue. I've had trouble with my external SD earlier (caused by the Voodoo fix on GB?), so I tried removing my SD, rebooted and gave it a shot. The wakelock is now gone, and my batterylife is great once again

Was unable to mount the faulty SD on my pc as well.

Hope this can help someone else

polarbearno