Recondition All Batteries
If you are using the GNOME desktop, you can add a Battery Status Monitor to your panel to keep track of the power levels of your battery. The following procedure steps you through adding the monitor to your panel and configuring it to behave as you like 1. Right-click the GNOME panel then select Add to Panel Utility Battery Charge Monitor. If the Battery Charge Monitor applet appears on the panel (which it should), you can stop here if you like. The applet will Show a power cord if the laptop is plugged in. Notify you with at pop-up window when the battery charge is low. Notify you with a pop-up window when the battery is fully charged. Display the percent charged and whether the battery is currently charging when you move the mouse pointer over the applet icon. Continue with the following steps if you want to change that behavior. 2. Right-click the Battery Charge monitor applet, then select Preferences. Figure 10-7 shows the Battery Charge Monitor Preferences window and the applet...
The Low Battery Critical module sets a trigger time for notifying you that your battery is almost out of power. The time tells you how many minutes are left before the battery runs out of power. The remaining options determine what happens when that threshold is reached. The first two choices are Run Command and Play Sound. Each has a text box where you can enter the path to the command or the sound. The remaining options are System Beep, Notify, Suspend, and Standby. Suspend and standby are available only if usr bin apm has the setuid bit on.
This example provides information such as battery charge status, percentage of charge, as well as current system temperature and status of the AC adapter. FIGURE 2.15 Gnome Power Management allows you to monitor battery status and configure specific power-related actions, such as closing the lid of your laptop or pressing the power button. FIGURE 2.15 Gnome Power Management allows you to monitor battery status and configure specific power-related actions, such as closing the lid of your laptop or pressing the power button.
Like all electronic devices, CPUs operate at specific voltages. Most 80486 and earlier CPUs, and even some Pentium-class CPUs, operated at 5v. As CPU speeds increased, however, it became desirable to reduce the CPU voltage, in order to reduce the heat buildup inside the chips. Reduced operating voltage also helps lengthen battery life on laptop computers. Therefore, a plethora of new voltage requirements emerged during the Pentium CPU's lifetime. In fact, many Socket 7 CPUs require the use of dual voltages one setting for the CPU core and another for input output (I O) circuitry. Dual-voltage CPUs generally run the I O voltage at 3.3v and the core voltage at some lower level, although in some cases the core voltage may be higher.
Setting Visual Effects to Normal or Extra can cause unexpected graphical artifacts, shorten battery life, and reduce performance in 3D applications and video playback. If you are having problems with an Ubuntu system, try setting Visual Effects to None and see if the problem goes away.
Apm provides access to battery status information and may help conserve battery power, depending on your laptop and the implementation. It has mainly been superseded by newer power management schemes, such as ACPI. Both acpi and apm enable hardware events such as the end of battery power or the pressing of a button to be controlled by software, and both provide the control daemons apmd and acpid, respectively.
Next, in the upper-right corner, you can see the current battery status, the current network status, an icon that helps you adjust the volume on your sound card, and the current date and time. If you move your mouse cursor over any of these, you see a current status summary if you click an icon once, you get access to a quick menu that lets you perform tasks related to the program. For instance, Figure 2-2 shows what you see if you click the date-and-time indicator.
Embedded projects start with selecting hardware. Based on the requirements of the project, such as cost, battery life, communications, and user interface, a few processors and technologies become obvious choices. For example, low-power consumer devices frequently use ARM processors, and industrial control applications frequently use Intel x86 parts. The hardware selection doesn't occur in isolation the team selecting the hardware must at the same time consider the peripheral devices and driver availability. Chapter 17 goes into detail regarding the development process unique to embedded projects. examples of these devices. For these projects, an industrial designer has authored a case that the hardware must fit into without altering the design too much. For a cell phone, the appearance as much as the capabilities matter to the end user. Products that fall into this class usually have strict power budgets for two reasons battery life is a selling point, and the battery is the largest...
With powertop, it is easy to see that some applications have fairly heavy energy requirements. For example, if your battery life is 5 hours, then running Gaim will consume 1 hour of that Other notable applications include the midbrowser (Firefox), xorg, and Skype. It should be noted that, especially with Firefox, much work has been done recently to reduce wakeups.
There is also the port to the armel architecture . This first release is based on the Freescale I.MX515 processor, which is a chip that apparently draws very little power and generates very little heat. This allows developers to squeeze longer battery life (up to 8 hours) out of a very thin form factor.
All modern hard disks come with the ability to spin down their motors to save energy. Then, when data is requested, the motors spin up again. There may be a slight delay while this happens, and some people dislike using disk spin-down because of this. However, on a notebook, it can lead to a substantial increase in battery life. On a desktop system, it's worth considering, because over the lifetime of a computer, it can save a lot of electricity (and therefore money ).
Most modern processors can slow down the internal clock of the processor to conserve power and battery life. Linux supports this ability and offers a variety of power governors. Different governors implement different heuristics in order to determine how to vary the processor speed depending on the system load and other variables.
Figure 10-7 View battery status from the Power Management applet in the GNOME panel. Figure 10-7 View battery status from the Power Management applet in the GNOME panel. On Battery Power The same options described for running on AC power are available for when your laptop is running on battery power. You can set what happens to the CPU and display after set amounts of idle time.
You probably bought your netbook for its portability, right That means you want its battery to last as long as possible. Ubuntu Netbook Remix offers some options to increase battery life beyond the default. Before you make any changes, look at the currently remaining battery life. You can do that by moving your mouse cursor over the battery power option in the upper-right corner of the screen (see Figure 7-5). Computer is runningon battery power Laptop battery 3 hours 45 minutes remaining (75.0 ) Laptop battery This option shows information about the battery power remaining. The very useful window provides detailed device information, including the total charge time your battery needs, the time it takes to discharge completely and very important the current capacity. As you can see in Figure 7-6, the capacity of my netbook's battery is 97 , which is good. The lower it gets, the faster your battery will empty. Check this option from time to time to find out if it's time to buy a new...
Laptop computers are often run on battery power. Most laptop batteries can run for only a couple of hours. Therefore, modern laptops include various power management tools that can dramatically reduce the computer's need for power, thus extending battery life. The 2.4.x Linux kernels include two sets of power management tools Advanced Power Management (APM) and Advanced Configuration and Power Interface (ACPI). Both require underlying support in the computer's BIOS. As of the early 2.4.x kernels, APM is To use APM features effectively, you need some way to tell the computer when to enter power-conserving states. This task is accomplished with the apmd package which ships with most Linux distributions and may be installed automatically. The main apmd program is a daemon, so it should be started when the computer boots. Once running, it monitors the system's battery status and, if the battery's charge gets too low, apmd kicks the system into a suspend mode in which most functions are...
The requirements for the device govern all of the following steps an inexpensive device won't have a aluminum case, a device that is sold to IT departments needs to fit in a 19-inch telco rack, and a music player should have a long battery life and lots of memory. The act of designing the device has an impact on the requirements as it's tested with potential users the user of the music player may use the device while exercising, so a heart monitor, calorie counter, or stopwatch may be an essential or differentiating feature of the device. What processor can be used What is the battery life
SUSE Linux continues to improve upon some features that are important to laptop users. When you run your laptop on its battery, you want to conserve power by shutting down various parts of the system when you are not doing work. SUSE Linux can do this through its support for ACPI (Advanced Configuration and Power Interface). You can access the power management module from an icon on the panel (it's the icon that looks like an electric plug). From this module's menu, you can see how much battery life is remaining and suspend the system to the disk so that you can resume later without having to go through a lengthy system reboot.
If you are using mobile computers like a laptop, a widget in your panel displays the battery status and gives you access to power management functions. If the Battery Monitor widget is not displayed in your panel by default, add it manually. For more information, refer to Adding Widgets to the Desktop (page 41). The widget allows you control the screen brightness when your system is running on battery power, to switch to a different power profile, or to trigger your system to enter a suspend mode. Click the panel icon to open the widget.
Normally, a computer's hard disks spin whenever the computer is turned on. This feature makes disk access swift, because there's no need to begin spinning the disk to access a file however, it consumes a fair amount of power. Therefore, as an energy-saving measure, spinning down a disk when it's not in use is sometimes desirable. Doing so is particularly helpful on laptop computers, on which a spinning hard disk can greatly reduce battery life. Therefore, hdparm supports the -S option to set this feature. Unfortunately, the encoding of this feature is rather odd, as outlined in Table 2.4.
We can estimate the best range and duration for the AUV using a basic fluid dynamics model of the AUV combined with data for power consumption and battery capacity. These calculations give a maximum range of 41km-51km at a cruise speed of 2.4m s with a duration of 6-8 hours. The model also estimated the maximum speed at 4.2m s.
CPU Frequency Scaling Some CPUs support changing their clock speeds on the fly, which can be useful for conserving battery life on laptops. Select this option (in the Power Management Options area) to add support for this feature. Check http www.brodo.de cpufreq for more information.
Linux includes a number of laptop-specific features, such as PCMCIA (or PC Card ) support and APM. The PCMCIA Tools package for Linux includes drivers for many PCMCIA devices, including modems, Ethernet cards, and SCSI adapters. APM allows the kernel to keep track of the laptop's battery power and perform certain actions (such as an automated shutdown) when power is low it also allows the CPU to go into low-power mode when not in use. This is easy to configure as a kernel option. Various tools interact with APM, such as apm (which displays information on battery status) and apmd (which logs battery status and can be used to trigger power events). These should be included with most Linux distributions.
Gnome-Power-Manager is a program with a graphical user interface that subscribes itself to power events and acts on them. It shows you the battery status on laptops and dims the screen if running on battery power, for example. It will also shut down or hibernate the computer after some idle time or before the battery runs out if a user is logged in. The software suspend policy of Gnome-Power-Manager is actually handled by the hardware abstraction layer.
Many types of embedded devices have different power requirements depending on their usage. For example, network routers need to have minimal energy consumption to avoid heating, especially when used under rugged conditions. Devices such as PDAs and cell phones need to consume less energy so that battery life is not cut short. This section explains the power management schemes available under Linux for embedded systems and the power management framework on Linux, which spans across the BSP, drivers, and application layers. But before that we discuss the nexus between hardware design and power management.
Obviously, older laptops can also be used for hacking. Any that are lacking a hard drive, have dead batteries, or have broken keyboards are particularly good value since the cost of new parts makes them too expense to rebuild, and having a laptop reliant on a tethered power line is not such a problem for home automation users as it is for others.
NOTE Tracker isn't activated by default because of fears over battery life with laptop computers Tracker has to frequently access the disk to build its index, and this consumes power. Some also have concerns about Tracker's affect on overall computer performance. The best bet is to give it a try. You can always turn it off if you don't like it.
While some information requires a response from the user (a low battery for instance), a large amount of the information generated by a system is purely informative and requires no user interaction. Notifications (provided through the notify-osd daemon or through the org.freedesktop.Notifications Dbus interface) provide for such a use case in that they do not provide actions for the user (they cannot be clicked and appear to hover and then fade). Semantically, the bubbles are either confirmations (brightness increased, for example) or notifications (new track playing).
Apmd contains a number of useful tools. apm can be used to query the current battery charge level and to set the system to standby (apm -S) or suspend (apm -s). Refer to the manual page of apm. The command apmsleep suspends the system for a specified time. To watch a log file without keeping the hard disk spinning, use tailf instead of tail -f. There are also tools for the X Window System. apmd contains the graphical utility xapm for displaying the battery charge level. If you use the KDE desktop or at least kpanel, use kbatmon to view the battery charge level and suspend the system. xosview is another interesting alternative. ACPI (advanced configuration and power interface) was designed to enable the operating system to set up and control the individual hardware components. ACPI supersedes both PnP and APM. It delivers information about the battery, AC adapter, temperature, fan, and system events, like close lid or battery low. Detailed information about the battery state. The...
Let's start with my favorite Kindle 2 improvement battery life. Of all the changes, this is the one I appreciate the most. With the wireless turned on, I can use the Kindle for several days before having to charge it. With the wireless turned off, I have to charge the Kindle only two or three times a month. This is a vast improvement over the original Kindle when I did not have the charger with me, I had to be careful never to turn on the wireless except when I wanted to purchase something or knew I had a subscription waiting for me to download. Turning on the wireless on the original Kindle is a sure way to kill your battery life. for turning the Kindle's wireless on and off. This has both good and bad sides to it. For one, if you attempt to do something that needs the wireless, the Kindle 2 offers to turn the wireless on for you. On the other hand, it takes more effort to turn the wireless off now that it is not a physical switch. It takes only a couple clicks from anywhere in the...
There also are a few things the original Kindle had that the Kindle 2 does not. For one, the Kindle 2 does not have a removable battery. This seems to be a trend among consumer electronics manufacturers these days. It's a trend I do not like. Maybe it was necessary to get the desired thinness and battery life, but I still would prefer a removable battery. If the battery dies on my Kindle 2, I likely will have to send it in to Amazon to be fixed. On my original Kindle, I can replace the battery myself and even carry around spares.
Laptop mode is a special page writeback strategy intended to optimize battery life by minimizing hard disk activity and allowing hard drives to remain spun down as long as possible. It is configurable via proc sys vm iaptop_mode. By default, this file contains a zero and laptop mode is disabled. Writing a one to this file enables laptop mode. Many Linux distributions automatically enable and disable laptop mode, as well as modify other pdflush tunables, when going on and off battery. This would allow a machine to benefit from laptop mode when on battery power and then automatically return to normal page writeback behavior when plugged into AC.
Each module has a Hello World app as well as many proof-of-concept applications. These are useful for seeing what each module is capable of. For example, BUGmotion can store the data it gets from three different axes (X, Y and Z) and detect motion in various programmable ranges. Simply by using this module with a BUGbase, you could program BUG and toss it into your luggage before a flight to chart the data from each axis as it gets jostled around. Keep in mind the rechargeable battery life is currently three to four hours without AC power.
ThePower Control modules configure the energy-saving and battery settings for your system. The Energy module applies to all systems that have a monitor with energy-saving capabilities the remaining modules apply to laptop) or other battery-powered systems using the Linux Advanced Power Management (APM) or Advanced Configurati on and Power Interface (ACPI) features. The Laptop Power Control module is available only if your system supports APM and you set the setuid bit for the APM binary file. (Do this as root with the command chmod u+s usr bin apm. But be aware that there aresecurity issues with turning on the setuid bit.) In addition, both the Low Battery Critical and Low Battery Warning modules add Suspend and Standby to the possible options if this file is setuid. Suspend mode is designed for- times whenyou want to stop working (especially on a laptop), but want to be able to restart where you left off. Open applications are preserved in memory, the CPU remains active at a low...
Sometimes an application uses a certain color, graphical icon or sound as an indicator of its status or as a notification for users. A simple example is a battery-status panel applet the applet warns users that their laptop battery is low by changing the battery icon from green to red. Of course, if users are blind, neither the green nor the red icon will be helpful if a textual description is not provided. Color-blind users also will be unable to decrypt such a status indicator. As another example, a calendar application may have an audible alert with no visual
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.