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Notebook Battery Guide

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  • Notebook Battery Guide

    Why is your notebook not getting the battery life it's rated at even right out of the box? Are you doing something wrong or just different than what was done during testing to determine the specs?

    Well, I highly doubt you're doing anything really wrong, but there are probably things you can do better for more battery life. As for comparing it to what some companies rate their system at... good luck, those are often optimum conditions with a very light load.

    Notebook batteries

    Ni-Cad (Nickel Cadmium battery), and Ni-MH (Nickel Metal Hydride) were once highly used having 1.2 Volts per cell.
    Li-Ion (Lithium-ion) have now taken their place having 3.6-3.7 Volts per cell and are much more practical for today's power hungry notebooks. They have more power, higher voltage, less self drain, less weight, and can be smaller for the power you get. You will also not find the memory problems previous batteries were known for. I guess the only drawback is they're more expensive.

    Smart/dumb batteries

    You will find most if not all of today's notebooks use Li-Ion smart batteries. The fact that it's smart means it has circuits that report its charge level so you can estimate the battery life remaining or when it's about to run out.

    Batteries are over-all measured in "mAh" (Milliamps/hour)

    While the cells are arranged in 3 groups of 4 cells, it's actually wired to work as 3 parallel rows in 4 series to make its rated 14.8V. The circuit board you see is for distribution and smart circuitry. You will find this similar to most every smart Li-Ion battery pack used in notebooks.

    Getting more minutes on a charge

    There are many things you can do to increase your battery life at the cost of performance, comfort, and features. What many will do that need to maximize their battery life for example if they're going on a trip, is get their settings in order before heading out. Here's a few things you can do:

    Adjust LCD brightness
    Most notebooks will be set to dim the LCD automatically by default from the factory. Unplug your system to check the brightness to verify. Some will do it over a few seconds slowly so you don't notice it so you have to watch carefully. If you feel you could deal with the display being even more dimmed, then (Windows) right click your desktop background, go to "Properties", then click the "Settings" tab at the top. Click "Advanced" and you will often find your settings for brightness in there which can vary depending on the graphics chipset and software on your system. Sometimes you can find the graphics control panel or settings hot link in your lower right hand system tray depending on software.

    Turn it down to whatever you're comfortable with. The LCD is one of the biggest battery hogs most laptops face keeping fed.

    Set powersave modes
    Every time you take a 5-10 min break to run to the bathroom, talk, or think without computer intervention, you need to set your notebook up to do what you want during that time.

    Right click your desktop background and go to "Properties", click the "Screen Saver" tab. If you're planning on having the screen saver kick on, set it to "Blank" in the pulldown menu, then move on to the "Power" button you see below that.

    Hitting the power button should bring up a display with 5 tabs across the top on most notebooks running Windows XP:

    Power Schemes
    On the power schemes tab you will have a pull down menu for different schemes. These schemes have default settings which you can adjust using the menus below, so it really doesn't matter which you modify as the selected one is the one you're using. You can set up multiple ones for times you want different preset settings.

    The first setting you can set is your turn off monitor. This is as simple as it sounds, it cuts power to the LCD after the period of time you choose in which there is no interaction with the computer (mouse or keyboard movement). This, and the others are custom settings that work for you. The faster you set it to shut things off the better to keep the battery going, but set it too low and you may get annoyed. If you're reading a large article spending minutes at a time looking at the screen reading without touching the mouse or keyboard it can get annoying if your LCD is shutting off to save power.

    The second setting you should see is to turn off hard disks. You probably don't want to set any of these options to happen faster than the option above it, but may want to set them for the same time. This setting spins down the hard drives to save power.

    The third setting you should see is system standby. System standby will cut power usage drastically by shutting off power to unused devices and throttling down the used ones.

    The fourth and last option will be for hibernate. This will only show up if you have hibernate enabled under the "Hibernate" tab. Hibernate uses software to take all your settings and applications down as they currently are and places the image on your hard drive before shutting down the computer. It's a full shut down. When recovering from hibernation, it's basically booting up from the image to have everything open and running exactly as it was. Both standby and hibernate have been known to be buggy with some systems. It's recommended you try them both out manually to look for any issues and also have all your Windows updates. Wherever possible, I'd use standby over hibernate. Keep in mind Hibernate also can take much longer to recover from if you walk back and want an instant response.

    Your alarm settings can be modified here.

    Power Meter
    Shows current batteries and their power level status.

    Advanced is where you set up your manual enabled power savings. If you know you're getting up for 30+ minutes, no need to let the timer enable your power settings, you set them here to manually enable. You may choose to close the lid when you walk away to enable the feature, or you may set it for the power button or the sleep button if your notebook has that.

    So, you can set it to when you close the lid to go into standby and the system should come out of standby when you come back opening the lid and interact.

    This is simply where you enable Hibernate and apply it. The hibernate option will not show up in the other menus unless it's enabled here.

    Disable unused devices
    If you have devices you're not needing when on battery power, disabling them can also save you power. Right click "My Computer" and go to "Manage". In the window that comes up, click the device manager link to open it up to the right as shown. Expand the menus by clicking the "+" next to the items to show the devices in that category. Once you highlight the device, you will see the disable icon pop up all the way to the right top bar of the window as shown in the picture.

    Things to disable that you're not using:
    Floppy drive
    The list can expand or shrink depending on what devices you don't need and what your notebook has in it. For example, if you have a system with 2 internal hard drives not in raid, you may want to disable the 2nd hard drive for battery savings when you need it.

    Remove external add ons
    If you have those nifty USB lights and fans and need battery life, yank em. If you have any camera memory in a card reader you don't need, remove and disable it. PCMCIA cards for wireless or whatever you have it for can be removed if you're not using it on battery. This should be a given, but many people don't realize the power these things can pull.

    Disable unused services
    Any program you may have running in the background shut it down. You can close many apps by right clicking them in the lower right menu or system tray. Or you can stop programs from starting up during boot up by going to Start/Programs/Startup and also going to start/run and typing "msconfig".

    Notebook battery conditioning for the long haul

    Most people are familiar with battery "memory" which was known to be a possible problem with Ni-Cad. Li-Ion batteries used these days it's not so much of a problem. Some say to cycle the battery every month, cycling meaning to drain it completely and charge it to full with no interruptions. The problem was batteries developed a memory when not fully cycled to not use part of their capacity that wasn't drained. With Li-Ion battery packs, the memory isn't a problem and they do not need to be cycled and gain no benefit from it with some saying it hurts them more than it helps. It has been proven though that fully charged Li-Ion batteries in warm temps will lose their capacity over time faster. This isn't good for notebooks considering, when you're plugged in you're often @ 100% battery and the notebook is warm from usage. All you can really do is try to keep it cool for the best life of the battery. Keeping it cool may be just using it on a flat surface so it can breathe or using a notebook cooler to have it sit on. Reality is though, no matter what you do, Li-Ion batteries life expectancy is largely based on how old they are more than how much they were used. Many people feel they've degraded to the point of replacement within 2-3 years on most systems from my experience.

    So, other than keeping it cool, you want to keep the contacts clean. You can clean the contacts using alcohol and a q-tip.

    Notebook battery storage
    Li-Ion batteries should be stored in a room temp or cool area neither at full charge or fully discharged. Around half charge has shown to be the best.


    Batteries just don't live forever no matter what you do for them. You may be able to extend the inevitable, but there will be a time to say goodbye to that block of DC storage to replace it with one that actually works.

    At what point do you get a new one? That's totally up to you if you want to hold onto your current one until it can no longer even boot your notebook up. Most manufacturers allow ordering of replacement batteries even for discontinued notebooks for around or just over $100. There are also battery companies that offer same spec packs made to fit in your system.

    Can you actually rebuild your Li-Ion battery pack? Yes, you could (see image at the top of this guide), but it's not recommended. You can purchase the individual cells from many places out there. There are also various GUIDES to rebuilding them requiring solder skills and patience. But unless you're buying the cells in a huge bulk, the cost savings isn't really worth it.

    Since the FCC has a limit of 6600 mAh, one could modify their pack for better battery life, but again, it's not recommended. Improper power will destroy your notebook.

    Often your original, standard manufacturer warranty will cover the battery performance, but any type of extended warranty will sometimes, or actually usually NOT cover your battery no longer holding a charge.
    Justin Nolte
    [email protected]

  • #2
    Once again you are on top of it.

    Here is a site that has some exciting news about the future of our laptop batteries, along with all others. This site not only explains why our Li-ion batteries eventually die but how the future looks using new nano technology. The ramifications of this is mind boggling if you think about.

    A battery for a Sager NP9262 that will last up to 10 hours and outlive the laptop it came with? :shock:

    Sometimes living on a boat is like living in a cave.


    • #3
      Justin nice practical information.

      Only want to point out a couple of things that , well clarified or expanded. And one of them I do not support and am glad you did not get into.

      First just so all know if they don't. The "memory" Justin was talking about that Li-Ion do not suffer from but others do is called "memory effect". If you did not fully discharge a Ni-Cad or stop the charge short of full it would reduce the storage capacity. While Justin did say. I must strongly express Li-Ion do not suffer from this. You use your battery as needed, ie; you do not run it down just to run it down, you will gain nothing. Also if you are charging and need to stop you will not suffer any harm.

      All batteries have limited lifespans. While Li-Ion offer very good power to weight performance and capacity. They do suffer more than many other types regarding a loss of capacity from age and also more limited life cycles.

      Let's talk cycles. that is the number of times you can discharge and recharge your battery. For notebooks the numbers are usually 300 to 500 cycles. The two most informative sources on batteries are Battery University and NBR has a very good guide and discussion called the battery guide. Back to cycles, confuses many and as with much about Li-Ion's information can appear ambiguous even to those with familiarity. Consider a cycle a full discharge/charge. If you discharge to 50% then charge to 100% (or close) consider that a 1/2 cycle. So there is no reason you must fully discharge or charge as it will take from your battery's lifespan. Unless needed why do?

      As Justin said heat is the main degrader of Li-Ion battery's. The real things you can do are allow proper airflow to your notebook, not just the battery but the entire system as the cooler things are the cooler the battery will be. Do not store in hot places. The best most destructive example of this I can think of is, a car in the summer with the sun shinning in. Some who are extreme would not charge battery with computer on as the battery produces heat while recharging. I personally find that to be extreme but yes there is more heat.

      While I do not do this or believe in it as I use my notebook and want my battery in if needed. If you pulled your battery out when not using would reduce exposure to heat. You could even put in a plastic bag and place in the refrigerator. While that will extend the life it is very impractical in my opinion.

      On a technical note, and Justin brought up smart and dumb Li-Ion's. I would like Justin to give me one example of a dumb one? I say because over discharging or overcharging Li-Ion will destroy the battery. Whenever anyone talks of full discharge or full charge. They are taking the circuit into account. The circuit will not allow a discharge that is beyond the safe level. I think it may be 3%. It also will not allow overcharging. So consider when people use the terms full charge/discharge this has been taking into account. Never store a fully discharged battery as voltage leakage could allow an unsafe voltage drop that would ruin the battery. The circuit cannot do anything about leakage. One reason to store at 40% charge.

      Batteries lose capacity over time. That is normal. Nothing can stop that. Some information here explains how to retard that but nothing will stop it.

      Justin stated a standard voltage for batteries and said the capacity is stated in mAh's. He is correct in so far as mAh's is the common rating but with out knowing voltage it is useless. WHr's expresses a quantity, independent of voltage mAh's says nothing about quantity without voltage.
      i7-720 CPU HD5870 GPU
      8GB 1333MHz DDR3 2x500GB HDD