Donovan Colbert isn't impressed with Android device power management, but he offers a few tips that may help preserve your battery life.
As I mentioned in a previous post, "Android device power management sucks." If you're struggling with the battery life of your Android device, here's a list of several applications and a few tips that might help you get a handle on your issues. Before we get started, one disclaimer -- your Android device may be slightly different than the examples given here.
Advanced Task Killer
The general consensus is that most issues regarding Android battery life are frequently related to misbehaving applications and Android-related issues with managing applications and background tasks. There are numerous application killers, but Advance Task Killer is probably the most famous proposed solution to these issues -- and it's free.
As the name applies, Advanced Task Killer simply presents a list of active applications and allows you to "kill" them, freeing system memory and potentially reducing battery consumption. There are now many applications, including Astro File Manager and ES Task Manager that have built-in task manager utilities, and the Android Settings | Applications | Manage Applications menu will also allow you to stop applications via the "Running" tab. Be careful, though. A stopped application may quietly reload -- or worse, cause system instability.
Frequently, Advanced Task Killer and other task management applications are better at making an application shut down and stay shut down, but some apps are just persistent about restarting. It's also worth noting that many Android gurus recommend against manual task management. They urge users to let Android manage applications itself, saying that manual intervention may have the opposite result of that intended.
Ultimately, if you're having battery issues, manual vs. automatic task management is something you'll need to experiment with yourself, finding the balance that works best in your case. Personally, it's been my general experience that manual task management does not significantly increase battery life, but it does have a noticeable negative impact on the overall system stability.
Wheres My Droid Power
The simple, free app called Wheres My Droid Power will try to track and graphically display the things that are consuming power, by percentage, on your Android device. Again, this is very similar to an Android feature in Settings | Battery Manager - Usage Statistics. I find that using both can give you a fuller picture of just what is going on with energy consumption on your device. Wheres My Droid Power is also useful on devices where the Battery Manager usage statistics have been unreliable or outright broken, such as with the ASUS Transformer TF101.
CPU Spy is a free application that will tell you the various states that your Android device supports (as expressed in clock-cycle CPU speed) and how much time your device has spent in those various states. This, in turn, helps assist users in determining important information -- for example, if their device is every truly going into "deep sleep" mode or if it's "sleeping with one eye open" instead. Generally speaking, when you're not on your device, you want it to spend most of its time in a "deep sleep" state, coming out for small bursts to check notifications or being woken for calls. If you find that it's constantly spending time in a more active state, either full power or somewhere between full power and deep sleep, you can start to suspect that some task is preventing your device from sleeping and thus draining your battery life too rapidly.
One thing about iOS, especially on the iPad, is that the platform is very miserly with power consumption, regardless of what state you leave the Wi-Fi radio in. I never felt compelled to manage the Wi-Fi state very closely on my iPad. But I do suspect that some of the early issues with Wi-Fi connectivity and DHCP leases on original iPads were related to Apple's very aggressive policies on how the iPad managed the wireless radio when the device was put into a sleep mode.
On my Android devices, I find that it's a whole different story. If you want to maximize your battery life and standby time with an Android gadget, it's worth your time to add a widget that will allow you to quickly disable or enable a variety of different features when either putting your device to sleep or waking it. The worst culprit here is generally Wi-Fi. GPS and Bluetooth can also sap your battery life and standby time, but nothing seems to suck the battery juice on Android devices as quickly as an active Wi-Fi radio. Part of this may be related to recent research that indicates that Wi-Fi "power saving mode" may actually consume more power in heavy traffic environments.
The safest way to make sure that your Wi-Fi radio doesn't deplete your battery standby time is to simply disable it whenever it isn't needed or when you're putting your device into a standby/sleep state. Counter-intuitively, many Android users report a dramatic increase in battery run-time and standby after setting the Wi-Fi Sleep policy to never on their Android devices. If you're going to manage your Wi-Fi connection manually, the most familiar widget for Android users is probably "Power Widget" for $2.10 USD (there's also a Free Power Widget that offers slightly less functionality).
This widget puts a bar on your screen that typically has five buttons -- one for Wi-Fi, one for Bluetooth, one for GPS, one for "Refresh"/Sync, and another for backlight management. Aggressive management of your phone using this widget can see a dramatic improvement in battery life. I've fiddled with all of these functions and found that I maximize my standby time and active battery life by disabling Wi-Fi and Bluetooth, leaving GPS active, disabling Sync, and setting the backlight to "auto."
On Honeycomb, the familiar Power Widget is gone. On my ASUS Transformer, it's been replaced by individual, user-customizable widgets that can be configured for the same common tasks -- Wi-Fi, Screen Settings, Battery Use, Location and Security, etc.
A note about Sync: It's fairly well established that Sync is another culprit for poor battery life. Syncing Google or corporate e-mail alone has a notable impact on battery life, but many social networking apps like Twitter, Facebook, and Google+ will also set up auto-sync schedules and notifications. There's no universal way to control this for Android, and the controls that do exist may offer a variety of levels of granularity. Learn what those are for your device and experiment with the settings to find the results that provide the best balance of benefit vs. battery consumption.
I've found that I get the best results by disabling automatic sync universally and then manually checking new e-mail, tweets, or updates on Google+ and Facebook. Admittedly, this diminishes the advantage of having corporate e-mail update instantly. As a compromise, you might considering setting social media apps to manually update or to update only via Wi-Fi, and setting e-mail to update infrequently (every 1 to 4 hours).
On Honeycomb devices and the Droid 1, you'll find a far more granular set of Sync controls in Settings | Accounts & sync | General sync settings (and Manage Accounts). For the Droid 2, see Settings | Data Manager | Data Delivery | Email and Corporate Sync (and/or Social Applications).
Another avenue you might try is a profile manager like they very popular "PhoneWeaver." Profile managers allow you to create different profiles that activate under defined circumstances, including time, location, if the phone is on battery or external power, and other criteria. PhoneWeaver Trial offers very granular control over almost ever facet of battery consumption on your device for a 12-day limited trial period. If your results are positive, you can buy the full version for $3.99 USD.
Personally, I'm unwilling to put the time and effort into customizing profiles at enough depth to leverage the value of applications like this. However, if you're an A-type personality who obsessively tinkers with your systems, profile managers like PhoneWeaver are probably going to give you a lot of bang for your buck.
Do you have any suggestions, advice, or favorite apps or techniques that I've missed? Let us hear about your tricks to maximize Android battery life in the discussion thread below.
- Five tips for saving battery life on an Android phone
- Save battery life on your Android phone with Advanced Task Killer
- CNET: How to see which apps are draining your Android device's battery
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