[General Topics] stuartv:
There is a widespread problem with a process called "Exchange Services" on Android that rapidly drains device batteries. I have found references to the problem going at least as far back as Android 4.0. I can personally confirm that it happens on Android 4.4.2. And it happens on just about all devices, as far as I can tell.

I have:

Samsung Galaxy Note 10.1 (2012), on Android 4.1.2

Samsung Galaxy S4 (Verizon), on Android 4.4.2

Samsung Galaxy Tab Pro 8.4, on Android 4.4.2

For email, I have an Exchange account for work and an Exchange account for my personal domain.

Work email is on Exchange Server 2010 w/SP1.

Personal email was on Exchange Server 2007, up until around April.

Then it was on Exchange Server 2010 w/SP3, up until yesterday.

Now it is on Exchange Server 2013.

I have never had this problem on any device, with my work email (Exchange 2010 SP1).

I never had this problem on any device, when my personal email was on Exchange 2007.

I had this problem on all 3 devices after my personal email was upgraded to Exchange 2010 w/SP3.

I don't have this problem on any device now that my personal email has been moved to Exchange 2013.

On my S4 and my Note 10.1, I was able to get the problem to go away by deleting my personal Exchange account from the device, rebooting into Recovery and wiping cache, then re-adding the Exchange account to the device.

On my Tab Pro, nothing I did made the problem go away (when my personal email was on Exchange 2010 w/SP3). I went as far as doing a factory reset to completely wipe the tablet, then only adding the personal email account. And many other combinations in between. Nothing helped. I've had my Tab Pro 8.4 for about a month now and I have had to charge it every single day. If I didn't, it would die in less than 24 hours, even if I didn't use it at all. The only thing that would keep it from dying would be to turn off WiFi.

On my S4, I installed SafeStrap and the HyperDrive 17.1 ROM for a few days. I tried the S5 email client, the N3 email client, and the "stock w/security removed" email client (reflashing the whole ROM for each one) and they all exhibited this problem and I could not get it to go away. I finally Odin'ed back to the stock NC5 image and re-setup everything and had the problem. I deleted my personal email account, wiped cache, re-added personal email, and it went away again.

I enabled Exchange ActiveSync logging for my Tab Pro and for my S4 (can be done on the server, using Outlook Web Access, in Options) when it was having the problem and I identified what the actual problem is: The problem is that the device is constantly trying to sync and failing, so it keeps retrying continuously. Specifically, it is attempting to do a Sync on the Collection with CollectionID of "RI", which is the Recipient Info Cache collection. All the other collections sync okay, so your email, calendar, etc, sync and work just fine. But, the ActiveSync logs show that the Sync attempt on RI causes the server to generate an internal exception and then return a Status code of 8 (which, according to the documentation indicates that the collection has been moved or deleted).The device receives the status of 8 and immediately re-attempts to sync the RI. Over and over and over, once every 1 to 2 seconds. THIS is what was crushing the battery on my devices.

I investigated further and found that Microsoft actually has a patch available for this server bug. The KB article that describes the issue and provides the resolution is here:

http://support.microsoft.com/kb/2886469/en-us

The only thing that I feel like is still a mystery is why, for example, my phone would have this problem and then I could delete the account, wipe cache, and re-add the account and have the problem go away. Looking at logs of my phone syncing when it's actually working show that it Syncs RI and the server does not throw an exception. That is really strange. I guess I just have to settle for "stupid Microsoft!" and move on.

I spent the last couple of weeks trying to get my hosted Exchange provider (Apptix) to apply this MS patch to my server. They initially said they would have to test it in their lab, etc., and it could be a couple of months before they put it into production. Then, eventually they told me that they can't load it on my server with no explanation of why. In other words, Apptix SUCKS!! I was with them for years. They used to be MailStreet, but they changed names in the last year. I'm guessing AppTix bought MailStreet. MailStreet really used to be great! I would call Tech Support and the person who answered the phone would be totally competent and always handled any issue I had with 1 phone call - 2 at the most. Now that they are Apptix, their support sucks big green donkey parts. And, they more than doubled my monthly fees, in the name of premium support, too! How ironic!

With Apptix, after weeks of trying I was completely unable to get a resolution to this problem. They kept telling me it's just a known thing that devices using ActiveSync burn a lot of battery and I should just change my devices from Push to polling every 1 hour. They simply would not install the Microsoft patch that has been available for 9 MONTHS!

So, yesterday, I moved my domain to hosted Exchange with Rackspace.com. They are awesome. I was able to do the whole migration myself (except for one phone call to get them to add an Accepted Domain to my account for a subdomain that I need because I'm using Split Domain Routing - some mailboxes on Google and some on Rackspace), in about 2 hours. And I went from paying $33/month for 5GB of mailbox storage to $10/month for 100GB!

And, best of all, I moved all my devices over to my new account on Rackspace, where I'm on an Exchange 2013 server, and none of them have Exchange Services battery drain any more. My Tab Pro was burning through 80% of its battery in less than 20 hours. Today, it has been on battery for 15h 54m and battery is at 83%.

TL;DR: If you're having this problem, the FIX (vs some workarounds I've seen posted) is to either apply the Microsoft patch linked above to your Exchange 2010 server. You might have to upgrade it to Service Pack 3 first. OR, upgrade your server to Exchange Server 2013.

Caveat: I don't know for SURE that the MS patch will fix your problem, as I didn't get to try it. But, the problem description EXACTLY matches the logs I was generating, so I strongly suspect it will fix the problem.