[Fire HD 8 and HD 10 General] ¿GotJazz?:
Hi, all - I am always interested in maximizing battery life on all my devices. I'm getting pretty respectable battery life on my newly rooted HD8-6G. When my HD8 is off and idle, I am generally seeing about 1% battery drop every 5 days or so. I thought I'd share some of my discoveries, in case y'all are interested.

First, a screenshot to let you guys see what I'm trying to maintain:

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See those 0 mA and mA draws in the teens? That's the sign that my tablet is going about as low as possible for current draw.

Note: The app I use for monitoring battery current drain in real time on my Android devices is Battery Monitor Widget. It's the hands-down the best out there for seeing the actual current drain, and has a super-low footprint. I got the paid version, 'cause the developer deserves it. :). During the BMW initial setup, be sure to manually set your HD8's battery capacity to 4750 mAh. You can use the default settings for everything else. Also, you can put a BMW widget on your desktop if you use Nova Launcher, and use Link2SD to convert Nova Launcher to a system app.

I also use Wakelock Detector to monitor for wakelocks. Install Wakelock Detector as a system app (available on the menu). Also, be sure to enable "Advanced Mode". I also enable "Statistics since unplug", since that will give me the best information on whether a new tablet mod / app install has adversely affected battery drain with new wakelocks.

I have also installed and run Greenify.

So ... First and foremost, I use my HD8-6G primarily as a reader, and not my main tablet. As such, my tablet is almost always in Airplane Mode (probably over 99% of the time). This may be one of the most important things you can do to keep your battery drain down. While you should definitely enable Settings >> Power >> Automatic Smart Suspend, keep in mind that this does not fully turn off the WiFi when the tablet screen is off. I have found that the HD8 will almost always drain over 100mA per BMW reading if WiFi is enabled with the Auto Smart Suspend enabled. So, remember to manually go into Airplane Mode when you don't need WiFi .

Under Settings >> Wireless >> Location-Based Services, I have all apps "disabled".

Next, here are some Amazon apps that I have disabled without negatively impacting battery drain:

Disable OTA updates:

pm disable com.amazon.otaverifier

pm disable com.amazon.device.software.ota

pm disable com.amazon.settings.systemupdates

(Remember to also rename /system/priv-app/DeviceSoftwareOTA/DeviceSoftwareOTA.apk to something like DeviceSoftwareOTA_.apk_)

Disable Fire Launcher:

pm disable com.amazon.firelauncher

Disable Amazon Game Circle:

pm disable com.amazon.ags.app

Disable Amazon Silk Browser:

pm disable com.amazon.cloud9

pm disable com.amazon.cloud9.kids

Disable Parental Controls:

pm disable com.amazon.parentalcontrols

TESTING (So, drain is TBD)

Will be testing other apps shortly.

Here are a bunch of other supposedly "safe" apps that folks have recommended disabling:

(Legend: Green apps can be pm disabled and then pm enabled to go back to previous battery drain levels. Red apps will always drain your battery after you pm disable them, even if you pm enable them later. See more details below.)

pm disable com.amazon.geo.client.maps

pm disable com.amazon.geo.mapsv2

pm disable com.amazon.geo.mapsv2.services

pm disable com.amazon.webapp

pm disable com.amazon.webview

pm disable com.amazon.dp.contacts

pm disable com.amazon.dp.fbcontacts

pm disable com.amazon.photos

pm disable com.amazon.photos.importer

pm disable com.amazon.kcp.tutorial

pm disable com.amazon.kindle

pm disable com.amazon.kindle.kso

pm disable com.amazon.kor.demo

pm disable com.amazon.tahoe

pm disable com.amazon.unifiedshare.actionchooser

pm disable com.amazon.unifiedsharefacebook

pm disable com.amazon.unifiedsharegoodreads

pm disable com.amazon.unifiedsharesinaweibo

pm disable com.amazon.unifiedsharetwitter

pm disable com.amazon.windowshop

pm disable com.amazon.pm

pm disable com.amazon.recess

pm disable com.amazon.socialplatform

pm disable com.amazon.zico

pm disable com.audible.application.kindle

pm disable com.audible.application.store

pm disable com.goodreads.kindle

pm disable com.amazon.kindle.unifiedSearch​

However, I recommend caution before disabling any of these. Just because you can disable some of the above apps and have your HD8 still operate without any visible issue, I have found during my testing that disabling some of these

actually increases battery drain, and sometimes irreparably

. The battery drain occurs in Airplane Mode, not just when connected to the internet.

And by "irreparably", I mean this: I have found that once you pm disable some apps and battery drain increases, a pm enable on the same apps does not make the battery drain go back to the previous levels. For example, disabling com.amazon.kindle.unifiedSearch increased my battery drain, but reenabling com.amazon.kindle.unifiedSearch did not reduce the battery drain back to what it was before. The only solution I have found for this is sideloading the original v5.3.1.1 image again, and then re-rooting and starting over. But some apps can be pm enabled after seeing a battery drain increase, and the battery drain goes back to the previous levels. For example, com.amazon.webapp and com.amazon.webview increased battery drain when disabled, but the battery drain went back to normal when they were re-enabled.

Lastly (for now): Installing the Google app also creates an irrevocable battery drain. I saw the battery drain go up significantly when I installed the Google app, and that drain didn't completely disappear after I uninstalled the Google app. The drain never dropped below 100 mA after I uninstalled the Google app, even in Airplane Mode.

As a result, I had to re-image and re-root my HD8-6G. Getting pretty handy at that. :rolleyes:

I will keep you guys informed on my progress.

Cheers!

¿GJ?