I get an average of >12 hours battery life with very stable performance with these settings on my NC.
In short, this is how I think the Nook Color should have been done from the beginning. I have attempted to balance some goals that are pretty common to other users. This guide walks you through steps that will accomplish all of these goals, but you may decide to keep some and skip others.
Here is what this will do:
- Root your Nook Color and put a variant of CM7 ROM on it. This is an "AOSP", or "generic Android" installation. Nook Color comes standard with Android under the covers of B&N's launcher and suite of apps. Many of the tweaks and advantages in this guide cannot be had without first abandoning B&N's standard OS in favor of CM7.
- Enhance performance by overclocking. The Nook Color is 800MHz max clock rate from the factory, and this guide will allow it to run at 1.2GHz (50% faster), along with tweaking the governor settings to ensure you do not sacrifice battery life.
- Improve battery life. My goal was to have a device that I can use on flights between Austin, TX and Europe to read books or watch movies without access to a power outlet. I believe I have achieved that goal.
- Enhance stability. While many ROMs (such as the new ICS work) may favor bells & whistles and tinkering over stability, I want my device to be rock solid and never, ever crash. The goal here is a device that *just works*, much like Apple devices are known to *just work*.
- Smooth and responsive UI. One common complaint of Android devices vs. Apple stuff is on smoothness and responsiveness of the UI, in particular scrolling, screen switching, etc. Glitchy or erratic movements, abrupt or stuttery scrolling, etc. all gives a feeling of poor quality or lack of "polish" IMHO, and I have made an effort to fix this flaw in Android on the NC, mostly because the hacky feel distracts from my enjoyment of the device.
- Flexibility and efficient use of storage. My guide will swap the /emmc and /sdcard mountpoints as well as repartition the internal memory of the NC, with the goal of efficiently utilizing the internal storage space, and allowing the SD card to be used in a more portable fashion, not required for operation but interchangeable. Mostly this is because for me, I have a LOT of music and limited space on my 32GB SD card for other media. But on long trips, I may want to bring along movies to watch and they are far more portable when put on tiny microSD cards. So I want to be able to change SD cards and change the media content on my NC, without having to reboot or lose access to some apps.
These instructions will root your device and install a variant of CM7 onto your Nook Color in the internal memory, EMMC. This will destroy the original (stock) Operating System and you will lose whatever you had in your Nook Color before the install. It is destructive and likely difficult to reverse. If you have reservations about changing it or wish to change back, don't use these instructions. Try someone else's less-permanent means of doing so. You may screw up a step or I may have missed something, or your NC may not respond like I expect, so if you brick your Nook, then you are on your own. There is no warranty included with these instructions.
These instructions are for those of you who want a smooth, fast and stable NC Android experience, with exceptional battery life as well as efficient usage of internal and external storage. IMHO, this is how they should have done it from the factory. Someone else likely figured out a better way, but this is my way, and it works for me. You do this at your own risk.
This is not for those of you who want the Barnes & Noble experience. And this is certainly not for those of you who are on the fence about whether to re-flash. As far as I know, there is no going back, or if there is, it probably is hard to do. I don't know, because I never considered it.
There. Now you're on your own
I am not the developer of the ROMs, image files, tools for repartitioning, or any of the other stuff mentioned here. I simply am noting my method for doing the installation and settings. Full credit and thanks are due to all of the original developers of this content.
mr72's setup guide:
- Power up your brand new Nook Color and register the device. Note: I have seen a few refurb NCs that needed to be returned... don't skip registering it! Might save you some heartache.
- You will need two SD cards: the "boot SD", which will be used to install clockworkmod, the OS, and google apps; a "data SD" which will be used to install the repartitioning scripts and then can be used for data storage. You can use the same SD card for both, but you may want to reformat it after using it to install the OS. IMHO, 1G and 2G microSD cards are cheap and it makes sense to make the "boot SD" on one of these and keep it around for recovery, using a much larger microSD (16GB or 32GB) for data storage later.
- Use Win32DiskImager to write the 1gb_clockwork-22.214.171.124-eyeballer.zip image to the boot SD. You must run Win32DiskImager as administrator!
- Copy the following files to the "boot SD" which you prepared with Win32DiskImager (Note: do not unzip them.):
A. The CM7.20 Stable ROM
- Copy the following files to the "data SD" card (Note: don't unzip these either.):
- Power off your Nook. Put the "boot SD" card in (the one with the 1gb_clockwork image), and then power it back on. It should boot into ClockworkMod Recovery ("CWM").
Navigate in CWM using the volume up/down keys to go up and down, N button to accept, power button to go back.
- Optional: Now is a good time to back up the factory OS. Use "Backup" from the ClockworkMod menu.
- Go back and navigate to "Install .zip from sdcard", then "Choose .zip"
Flash the files in this order:
- Once you've flashed the files, in the ClockworkMod main menu select "wipe data/factory reset"
- Go back to the main menu, remove the "boot SD" card and put in your data SD card. Choose "Reboot system now", which should boot into CyanogenMod (CM7). Note, it requires an SD card to boot at this time.
- Once you boot into CM7, you must add your Google account, which will require wifi access. You can set up wifi by using the menu on the status bar. It may be kind of tricky to set up the wifi and get through the wizard. But it will eventually work.
- Go to the market and search for "ROM Manager", and install the latest version.
Then just open up Rom Manager from the app drawer and hit "Flash ClockworkMod Recovery" and choose "Nook Color". It's on the list, even though the list may not be in any discernible order.
- Optional: While in the market, you probably want "ES File Explorer", makes life easier when trying to navigate files.
- Reboot into recovery, and back up the current ROM. Seriously, now make a backup. This is a basic starting point before you add apps and do a lot of tricky stuff, so this is an excellent place to make a backup that may save you later.
- Install the reformat/repartition using precise instructions in this thread
Follow the instructions to use custom 1.96GB "/data", 4+GB "/media" partitioning to the precise detail.
This process is destructive and may feel quite risky. I suppose it is! So be careful and don't make a mistake here. It is worth it. By repartitioning you will wind up with 2GB of space for apps (vs. 1GB stock) and the other 4GB is usable as temp storage (like an SD card). This will also allow you to run your Nook Color with no SD card installed, plus hot-swap SD cards with no effect on running apps.
- Now, back to Menu -> Settings -> CyanogenMod Settings
ApplicationNote: This will cause the SD card to be mounted at /emmc and the internal 4G partition will be mounted at /sdcard. The result of this is your actual SD card does not have to be installed in order for the NC to work, apps that require /sdcard for storage will use the internal memory. This also means your SD card can be "clean", with only media on it, and interchangeable so you can have more than one SD card with content. The 2GB partition will be used for apps. You will have a hard time running out of application storage space with 2GB.
- uncheck "Allow application moving"
- Install location: "Internal"
- check "Use internal storage"
- uncheck "Permission management"
If you didn't repartition, then you will have 5GB for apps and only 1GB will be used for /sdcard stuff, which IMHO, is too little space for the /sdcard temp/settings storage, and way more than you can ever use for apps (certainly if your apps require sdcard space). So the repartition is IMHO necessary to make the sd/emmc swap feasible.
- Install the V6 Supercharger script, update 8. Download it and use ES File Explorer or other tool to move it to the root level of the SD card partition (/mnt/sdcard). You will have to run the script in Terminal Emulator with the following commands:
suNote: this changes the way apps' memory is managed and results in more available memory for the active app more often. This makes things faster. However, you may find that it winds up killing background apps more frequently, so there is a tradeoff. So if you pause your Angry Birds game and go do web surfing for a couple of hours, Angry Birds may have to restart when you return to it rather than staying in memory the whole time. FYI.
Also Note: There are some other tweaks floating around that are said to improve performance; in my observation, they do not really improve it, and they are not necessarily persistent across boots. The V6 Supercharger does the trick, and doesn't require anything else to get the job done, IMHO.
- Some performance tweaks, if you want iPad-like scrolling and smoothness and 12+ hours of battery:
Menu -> Settings -> CyanogenMod Settings
Performance (say OK to the "Dragons ahead" warning)You will have to reboot for these to take effect.
- CPU Settings
- Governor: InteractiveX, min 300, max 1200, set on boot checked. Note: the Conservative governor may result in better battery life, InteractiveX will result in a more responsive device. I switch between the two depending on whether I need long battery life, such as on a long flight where I plan to read or watch movies.- Use JIT - checked
- Enable surface dithering - checked
- Use 16bit transparency - checked
- Allow purging of assets - checked
- Lock home in memory - checked
- Lock messaging app in memory - unchecked (there is no messaging on a NC)
- Undervolt/Frequency settings (this improves battery):
Run the Nook Tweaks app
CPU Stepping 1: 350mhzVoltage Settings
CPU Stepping 2: 600mhz
CPU Stepping 3: 800mhz
CPU Stepping 4: 1000mhz
CPU Stepping 5: 1200mhz
Set on boot: Checked
Stepping 1: 0.925v
Stepping 2: 1.05v
Stepping 3: 1.2v
Stepping 4: 1.275v
Stepping 5: 1.325v
Note: you can set the CPU minimum to 300 MHz to eek out a tiny bit more battery but when I do this, I get occasional SOD that are alleviated completely by using 350 MHz min.
I continue to update this whenever I have something meaningful to report. The truth is that for months now I have just basically been using my Nook Color regularly with no problems whatsoever, so this doesn't really require regular attention. Once ICS is fully-baked, I am sure I will come up with an alternative using ICS. For now, this setup appears to be rocking.
With this setup, with wifi disabled I achieved over 17 hours of battery life while reading ebooks with Moon+ Reader and the screen on (not night mode, this is white background, black text, and brightness about 10%). I also got about 10 hours of battery while watching movies. I think this is pretty great battery performance.
I have completed my experiments with CM10 and CM10.1 and (drum roll!)... they are not good choices IMHO for NC.
Battery life was about 1/2 on CM10 or CM10.1 what it was with CM7.20 and performance was very sluggish. Web browsing in particular is almost useless. I found I ONLY used my NC for reading books (since Moon+ Reader worked just fine) and I seriously hated having to use it for anything else.
The battery would not last throughout one overseas flight just reading books.
Just not nearly enough battery and performance for me, and while I like some of the UI enhancements (and particularly the ability to use Chrome browser) with CM10/10.1, they were in no way worth the extreme tradeoff in performance.
In the meantime I also dropped my NC and crunched the corner on it, so while it works, it does need to be replaced.
So, back to CM7.20 for me on the NC. I'm actually following my own guide right now to get it rebuilt the way it was. I'll be shopping for a new tablet to get maybe this summer that will run CM10+ with performance like I was getting from my lowly NC. Long live CM7.20 on NC!