Battery Life Ebooks Catalog
This product contains a Li-ion battery. There is a risk of fire and burns if the battery pack is handled improperly. Do not attempt to open or service the battery pack. Do not disassemble, crush, puncture, short external contacts or circuits, dispose of in fire or water, or expose a battery pack to temperatures higher than 60 C (140 F). WARNING Danger of explosion if battery is incorrectly replaced. To reduce risk of fire or burns, do not disassemble, crush, puncture, short external contacts, expose to temperature above 60 C (140 F), or dispose of in fire or water. Replace only with specified batteries. Recycle or dispose of used batteries according to the local regulations or reference guide supplied with your product. Note This product should be operated only with the following designated Battery Pack(s). HTC, Model TWIN160
Persist data between sessions, and when the application isn't visible, suspend tasks that use processor cycles, network bandwidth, or battery life. If your application has processes that need to continue running while your Activities are out of sight, use a Service, but hide these implementation decisions from your users.
You can extend your battery life by limiting your data connections to 2G networks (GPRS or EDGE). When you are connected to a 2G network, you may want to postpone activities that transmit a lot of data, such as sending, uploading, or downloading pictures or video, until you are connected to a faster mobile or other wireless network.
An Android application should be fast. Well, it's probably more accurate to say that it should be efficient. That is, it should execute as efficiently as possible in the mobile device environment, with its limited computing power and data storage, smaller screen, and constrained battery life.
Developers who enable LBS support in applications need to be aware of a number of issues. First and foremost, a user's location is personal information and subject to privacy concerns. Second, using LBS on a handset takes a toll on the device in terms of network data usage and battery life. Handle events such as low-battery warnings and adjust how your application runs accordingly.
A live wallpaper is similar to an Android Service, but its result is a surface that the host can display. You can create a live wallpaper as complex as you like, but handset responsiveness and battery life should be taken in to account. Some examples of live wallpapers include
NOTE APNdroid is a free app that simply turns your data access off by renaming all of your APNs (access point names). This is a simple fix for a vexing problem, and it can even save battery life for times when you're not traveling. Double-check your phone compatibility before installing it. APNdroid does not work with Motorola DROID, and if you choose to uninstall it, make sure you do so when data is enabled, or you'll leave yourself stranded with renamed APNs.
GPS radios and processors are fairly inexpensive, but still, an increase of even 10 in the bill-of-materials cost of a mobile phone is considerable. Reduced battery life There have been great strides in reducing the power required by GPS radios and processors, but they still suck battery power. Most phones that include GPS also have a feature that lets the user turn it on and off. If your application depends on GPS accuracy, it's good to remember that your application might have to check whether the GPS device is turned on and notify the user if it isn't.
It might be bad for the immediate user experience, if the list appears to be sluggish. More likely, though, it will be bad due to battery usage every bit of CPU that is used eats up the battery. This is compounded by the extra work the garbage collector needs to do to get rid of all those extra objects you create. So the less efficient your code, the more quickly the phone's battery will be drained, and the less happy the user will be. And you want happy users, right So, let us take a look at a few tricks to make your fancy ListView widgets more efficient.
Mobile applications have unique requirements, due mostly to the constrained resources available to execute applications. For now let's focus on MapActivities and talk about a way we can help save battery power. The good news is that Android makes it pretty easy. In a mobile environment, battery life is everything, and if we're not the application that is currently being displayed, we want to do everything we can to minimize the power we consume. You recall from the discussion of the Android lifecycle (Chapter 1) that when an Activity (such as MicroJobs) starts another Activity (such as MicroJobsList) the new Activity takes over the screen, and the calling Activity gets pushed onto a stack of Activities that are waiting to run. At that time, Android calls the onPause() routine in the calling Activity so it can prepare itself to go into hibernation. At this point in MicroJobs.java (or just about any MapActivity that uses location updates), we want to turn off location updates. Doing so...
Even lower-end mobile phones typically bundle web browser, e-mail, and text messaging, but the power of the smartphones enables a wider array of applications. Smartphones are not just little computers that fit in your pocket. For many applications, they are actually more powerful devices than a laptop due to their built-in capabilities of camera, connectedness, and geolocation. Business people who can afford a laptop often prefer the longer-lasting battery power and portability of the smaller device. In an Information Week article, Alexander Wolfe collected real-world use cases of businesses adopting smartphones for applications that used to be only accessible with a desktop or laptop computer The company's field-sales reps tried laptops and tablet PCs, but their battery life was too short and rebooting took too much time on sales calls, which number 20 to 25 a day, says Mike Corby, director of direct store delivery. Dreyer's reps also found the laptops to be too bulky to tote around,...
To assure optimal phone performance and ensure human exposure to RF energy is within the guidelines set forth in the relevant standards, always use your device only in its normal-use position. Contact with the antenna area may impair call quality and cause your device to operate at a higher power level than needed. Avoiding contact with the antenna area when the phone is IN USE optimizes the antenna performance and the battery life.
That's why it's very important to consider performance when you write Android applications. These systems are not that fast to begin with and they are also constrained by their battery life. This means that there's not a lot of horsepower to spare, so when you write Android code it's important to write it as efficiently as possible.
Mobile phones today are very powerful handheld computers, but they are still limited. The fundamental limitation of a mobile device is battery capacity. Every clock tick of the processor, every refresh of memory, every backlit pixel on the user's screen takes energy from the battery. Battery size is limited, and users don't like frequent battery charging. As a result, the computing resources are limited clock rates are in the hundreds of MHz, memory is at best a few gigabytes, data storage is at best a few tens of gigabytes. Throughout this book we will talk about the mechanisms included in Android to optimize for these limited resources.
Opening and switching applications 32 Working with menus 34 Options menus 34 Context menus 34 Monitoring your phone's status 36 Status icons 36 Notification icons 37 Managing notifications 38 Searching your phone and the web 40 Searching the web by voice 44 Locking your screen 45 Customizing the Home screen 46 Connecting quickly with your contacts 49 Optimizing battery life 50
Manufacturers of embedded devices, particularly mobile devices, generally value small size and long battery life over potential improvements in processor speed. For developers, that means losing the head start traditionally afforded thanks to Moore's law (the doubling of the number of transistors placed on an integrated circuit every two years). In desktop and server hardware this usually results directly in processor performance improvements for mobile devices it instead means smaller, more power-efficient mobiles without significant improvement in processor power.
Background threads, while eminently possible using the Android Handler system, are not all happiness and warm puppies. Background threads not only add complexity, but they have real-world costs in terms of available memory, CPU, and battery life. The possibility that your user will get irritated if you chew up a lot of CPU time and battery life without giving any payback. Tactically, this means using ProgressBar or other means of letting the user know that something is happening. Strategically, this means you still need to be efficient at what you do background threads are no panacea for sluggish or pointless code.
Background threads, while eminently possible using the Android Handler system, are not all happiness and warm puppies. Background threads not only add complexity, but they have real-world costs in terms of available memory, CPU, and battery life. The possibility that your user will get irritated if you chew up a lot of CPU time and battery life without giving any payback. Tactically, this means using ProgressBar or other means of letting the user know that something is happening. Strategically, this means you still need to be efficient at what you do - background threads are no panacea for sluggish or pointless code.
Battery life estimates (approximations) Talk time Up to 420 minutes for WCDMA Note Battery life is subject to network and phone usage. Do not attempt to open, disassemble, or service the battery pack. Replace only with the battery pack designated for this product. Recycle or dispose of used battery as stipulated by local regulations.
The About phone screen, shown in Figure 15-17, is a brain dump of information that describes almost everything about your G1's software and hardware software versions, details on signal strength and battery life, and even a cute scrolling marquee of individuals and companies that have contributed their blood, sweat, and tears to make Android a reality (touch Contributors to see this moving tribute). You may need to come to this screen on occasion to read pieces of information requested by T-Mobile customer service, but otherwise, you probably won't be visiting often.
The SetCPU app makes managing a stable overclock very easy. By default, it gives your phone a moderate speed boost, but you can customise it further for more dramatic on-demand overclocking. More power means that battery will drain more quickly, but we found using SetCPU with a substantial on-demand overclock had little effect on our device's battery life. If
The screen backlight on most Android phones uses an awful lot of battery-power. Though you can globally tweak the timeout that turns off the backlight, in some circumstances you just don't want it to go out. Maybe you're using an app while driving, or you might have an app that loses data or switches off altogether if the phone happens to lock up its screen while the app is running. For those times, there's KeepScreen. The KeepScreen app lists all of the installed apps on your phone then, with a tap, you can indicate which ones the screen shouldn't cut out on white they're running. With KeepScreen you can turn down the screen backlight timer to its lowest setting - 30 seconds - and preserve battery life, while retaining full functionality and control over the apps you need to use. Sounds good to us. The biggest issue with just about every smartphone is its battery life (or lack thereof). Android devices are no different, and the scope of their problems even tends to be greater because...
Your current phone may well have such icons, to indicate battery life, signal strength, whether Bluetooth is enabled, and the like. With Android, applications can add their own status bar icons, with an eye towards having them appear only when needed (e.g., a message has arrived).
You were introduced to some of the design considerations involved in developing mobile applications, particularly the importance of optimizing for speed and efficiency when increasing battery life and shrinking sizes are higher priorities than increasing processor power.
DIY Battery Repair
You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.