Software Development

Maximizing laptop and cell phone battery life

Climbing mountains isn't the only time you hope you have enough battery power. Here are some support tips for making sure phones and laptops stay powered up.
TechRepublic editors Mike Jackman and David Bard are currently trekking through Nepal on their way to the Imja Tse peak at 20,285 feet. On their high-altitude journey, cut off from civilization, they will be dependent upon rechargeable batteries to keep their high-tech equipment up and running. If you rely on your laptop or your cell phone for your job, you know how important it is to make sure your battery is functioning properly. Here’s an overview and some tips for keeping your portables powered up.
For some people, portability is critical. They rely on their laptops and cell phones every day in order to get the job done. If these tools cease to function, production slows to a crawl or stops altogether until the laptop or cell phone is functioning again. I'm sure there are far too many stories of projects that didn't get finished or deals that didn't get closed because the battery died in either someone's laptop computer or cell phone. How can this be avoided? How can you maximize the life of your portable battery? Here is some general information and care tips for the most common portable batteries that will help you do just that.

First, the basics
Before you can maximize the life of your portable battery, you need to determine what type you are using. When it comes to portable batteries, there are only a few choices on the shelf. The three dominant types of rechargeable batteries in use today are Nickel Cadmium (NiCd), Nickel Metal Hydride (NiMH), and Lithium Ion (LiIon). Here is a brief description of each one.
  • NickelCadmium(NiCd) is the most prevalent and rugged type of rechargeable battery on the market. NiCd batteries perform better in extreme temperatures and can endure approximately 750 charge and discharge cycles. However, they are prone to "memory effect" (discussed later) when they are not completely discharged each cycle.
  • NickelMetalHydride(NiMH) is a step up from NiCd batteries. It offers up to 40 percent additional capacity compared to a NiCd battery of equal size. NiMH batteries are not as subject to memory effect degradation. These batteries generally have a life expectancy of approximately 400 charge/discharge cycles.
  • LithiumIon(LiIon) is the newest technology in portable power. LiIon will deliver roughly twice the run time of a comparable NiMH battery. LiIon batteries are more expensive, however, and are available for a very limited number of devices. They must also be charged by a charger designed specifically for LiIon batteries. LiIon technology also has a life span of about 400 charge/discharge cycles and is completely immune to memory effect.

What is memory effect?
NiCd batteries, and to a negligible extent, NiMH batteries, suffer from what is called "memory effect." Memory effect occurs when a battery is only partially discharged before being recharged. The battery "forgets" that it has the capacity to further discharge all the way down. For example, if on a regular basis, you fully charge your battery and then use only 50 percent of its capacity before the next recharge, eventually the battery will become unaware of its extra 50 percent capacity, which has remained unused. The battery will remain functional, but only at 50 percent of its original capacity.

The way to avoid memory effect is to fully charge and then fully discharge the battery at least once every two to three weeks. This can be done by letting your laptop or cell phone run on the battery until it ceases to function. Avoiding memory effect, however, is only one step toward maximizing the life of your battery.

Maximizing means maintenance
Once you have determined the type of battery that you are using, or will use, you must provide the necessary maintenance for the battery in order to maximize its life and usefulness. This begins when you take the battery out of the box and before its initial use.
  • Initializing. New batteries come in a discharged condition and must be fully charged before use. NiCd and NiMH batteries should be charged for approximately 16 hours initially, and LiIon batteries should be charged for about five to six hours. For NiCd and NiMH batteries, you should run your battery through at least two to four full charge/discharge cycles before putting it into ordinary service. This will help obtain maximum capacity of the battery.
  • When charging the battery for the first time, the device may indicate that charging is complete after just 10 or 15 minutes. This is normal with rechargeable batteries. New batteries are hard for the device to charge because they have never been fully charged and are not “broken in.”Sometimes the device's charger will stop charging a new battery before it is fully charged. If this happens, remove the battery from the device and then reinsert it. The charge cycle should begin again. This may happen several times during the first battery charge. Don't worry. It's perfectly normal. Batteries that have been in storage or out of use for long periods of time should be re-initialized before being put back into service.
    • Conditioning. NiCd batteries must be fully discharged and then fully charged every one to three weeks, depending on frequency of use. Failure to do so will result in "memory effect" and will significantly shorten the battery's life. To discharge, simply run the device under the battery's power until it shuts down or until you get a low battery warning. Then recharge the battery as instructed in the user's manual. Because the NiMH battery has negligible memory effect and the LiIon battery has no memory effect, they do not require conditioning.
    • Exercising. The workload on a battery directly affects its run time. In order to maximize battery life, users can apply the following tips to increase the usage time and life of their batteries.

    Laptop users
    How can laptop users conserve battery power? Here are some tips:
    • Optimize the power management features provided on your system. Managing the power used by the hard drive will save significant amounts of power and will extend your usage time.
    • Decrease screen brightness. On color systems, you can save quite a bit of power by changing to black-and-white (monochrome) mode.
    • Turn off the modem, if possible, and remove any Personal Computer Memory Card International Association (PCMCIA) cards not in use.
    • Don't leave the power cell in the system with the AC adapter plugged in unless you're charging it.

    Cell phone users
    Here are some tips for cell phone users:
    • Consider the type of cellular phone and technology (analog or digital) you are using. Some phones require less power.
    • Consider the number of features in use. More features require more power.
    • Roaming requires more battery usage than using a local network.
    • Your usage habits will obviously affect the amount of run time you will get from each charge.
    • Antenna efficiency, network efficiency, operating temperature, and proximity to a cellular antenna site will also affect battery consumption.

    A few more pointers
    Be sure to clean dirty battery contacts with a cotton swab and alcohol. This helps maintain a good connection between the battery and the portable device. Also, if you don't plan on using the battery for a month or more, store it in a clean, dry, cool place away from heat and metal objects. NiCd, NiMH, and LiIon batteries will self-discharge during storage. Remember to recharge the batteries before use.

    When it's time to say good-bye
    Most people don't think of a battery as being consumable. After a certain number of charging cycles, your battery will no longer charge fully and will not give you its initial performance. This is due to normal wear and tear, and unfortunately, you can do nothing about it. You do have a couple of options at this point, however. You can dispose of your battery and buy a new one, or you can have the worn-out battery refurbished.

    If you choose to dispose of your battery, beresponsibleanddisposeofitproperly. Cadmium, nickel, and lithium are all elements that pollute the environment. Do NOT throw these batteries in the trash. If you don't know where your local recycling facility is, call the Rechargeable Battery Recycling Corporation at 1-800-8-BATTERY (1-800-822-8837). They will provide you with the address of the recycling center nearest to you.

    Refurbishing is an economical alternative to buying a new battery. Most battery packs can be rebuilt to like-new condition to provide you with more years of continued service.
    Want to win a TechRepublic baseball cap? Share your climbing experiences or give the guys encouraging words by posting your comment below, or send us an e-mail. It's that simple.And so you don't miss one step of David and Mike's climb up Island Peak, subscribe to our free TrekMail. Be one of the first 2,000 subscribers to our TrekMail, and you'll get a cool TechRepublic flying disc!
    The bottom line
    Proper maintenance is the key to a battery's longevity. Only you can control that. Whether you are someone who depends daily upon your portable devices or if you use them on an as-needed basis, implementing the aforementioned maintenance tips will give you confidence and security that your laptop or cell phone won't die when you need it most.

    Todd LeFort is a contributing author for TechRepublic. He works as a network administrator in Northwest Florida. Todd is planning to relocate to Connecticut in the summer of 2000 and is currently looking for employment opportunities there. To comment on this article, please post a comment below or follow this link to write to Todd.

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