Batteries in portable consumer devices (laptops, camcorders, cellular phones, etc.) are principally made using Nickel Cadmium (NiCad), Nickel Metal Hydride (NiMH) or Lithium Ion (Li-Ion) technologies. Each type of rechargeable battery technology has its own unique characteristics:

The main difference between the two is the fact that NiMH batteries (the newer of the two technologies) offer higher energy densities than NiCad’s. In other words, pound for pound, NiMH delivers approximately twice the capacity of its NiCad counterpart. What this translates into is increased run-time from the battery with no additional bulk to weigh down your portable device. NiMH also offers another major advantage: NiCad batteries tend to suffer from what is called the "memory effect". NiMH batteries are less prone to develop this dreaded affliction and thus require less maintenance and care. NiMH batteries are also more environmentally friendly than their NiCad counterparts since they do not contain heavy metals (which present serious landfill problems).

Li-Ion has quickly become the emerging standard for portable power in consumer devices. Li-Ion batteries produce the same energy as NiMH batteries but weigh approximately 35% less. This is crucial in applications such as camcorders or notebook computers where the battery makes up a significant portion of the device's weight. Another reason Li-Ion batteries have become so popular is that they do not suffer from the memory effect AT ALL. They are also environmentally friendly because they don't contain toxic materials such as Cadmium or Mercury.

NiCad batteries, and to a lesser extent NiMH batteries, suffer from what's called the "memory effect". What this means is that if a battery is repeatedly only partially discharged before recharging, the battery "forgets" that it has the capacity to further discharge all the way down. To illustrate: If you, on a regular basis, fully charge your battery and then use only 50% of its capacity before the next recharge, eventually the battery will become unaware of its extra 50% capacity which has remained unused. The battery will remain functional, but only at 50% of its original capacity. The way to avoid the dreaded "memory effect" is to fully cycle (fully charge and then fully discharge) the battery at least once every two to three weeks. Batteries can be discharged by unplugging the device's AC adapter and letting the device run on the battery until it ceases to function. This will insure your battery remains healthy.

NiCad, NiMH and Li-Ion are all fundamentally different from one another and cannot be substituted unless the device has been pre-configured from the factory to accept more than one type of rechargeable battery technology. The difference between them stems from the fact that each type requires a different charging pattern to be properly recharged. Therefore, the portable device's internal charger must be properly configured to handle a given type of rechargeable battery. Refer to the owners manual to find out which rechargeable battery types the particular device supports or use our QuickFind search engine to find the device in our database. It will automatically list all of the battery types supported by the machine.

New batteries are shipped in a discharged condition and must be charged before use. We generally recommend an overnight charge (approximately twelve hours). Refer to the user's manual for charging instructions. Rechargeable batteries should be cycled - fully charged and then fully discharged - two to four times initially to allow them to reach their full capacity. (Note: it is normal for a battery to become warm to the touch during charging and discharging).

New batteries are hard for the device to charge; they have never been fully charged and are therefore "unformed". 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.

There are several steps you can take to insure that you get maximum performance from the battery:

New batteries come in a discharged condition and must be fully charged before use. It is recommended that you fully charge and discharge the new battery two to four times to allow it to reach its maximum rated capacity.

Keep the battery healthy by fully charging and then fully discharging it at least once every two to three weeks. Exceptions to the rule are Li-Ion batteries which do not suffer from the memory effect.

It's a good idea to clean dirty battery contacts with a cotton swab and alcohol. This helps maintain a good connection between the battery and the portable device.

Do not leave the battery dormant for long periods of time. We recommend using the battery at least once every two to three weeks. If a battery has not been used for a long period of time, perform the new battery break in procedure described above.

If you don't plan on using the battery for a month or more, we recommend storing it in a clean, dry, cool place away from heat and metal objects. NiCad, NiMH and Li-Ion batteries will self-discharge during storage; remember to break them in before use. Sealed Lead Acid (SLA) batteries must be kept at full charge during storage. This is usually achieved by using special trickle chargers. If you do not have a trickle charger, do not attempt to store SLA batteries for more than three months.

To get maximum performance from the battery, fully optimize the notebooks power management features prior to use. Power management is a trade off: better power conservation in exchange for lesser computer performance. The power management system conserves battery power by setting the processor to run at a slower speed, dimming the screen, spinning down the hard drive when it's not in use and causing the machine to go into sleep mode when inactive. The notebook users guide will provide information relating to specific power management features.

There are two ratings on every battery: volts and amp-hours (AH). The AH rating may also be given as milliamp-hours (mAH), which are one-thousandth of an amp-hour (for example, 1AH is 1000mAH). The voltage of the new battery should always match the voltage of your original unless the batteries are different chemistries (NiMH and Li-Ion batteries have different voltage ratings, even if they're for the same laptop). Some Hi-Capacity™ batteries will have higher amp-hour ratings than the original battery found in the device. This is indicative of a longer run-time (higher capacity) and will not cause any incompatibilities.

The life of a rechargeable battery operating under normal conditions is generally between 500 to 800 charge-discharge cycles. This translates into one and a half to three years of battery life for the average user. As the rechargeable battery begins to die, the user will notice a decline in the running time of the battery. When a battery that originally operated the notebook for two hours is only supplying the user with an hour's worth of use, it's time for a new one.

NiCad, NiMH and Li-Ion batteries should be recycled. Be environmentally conscious - do NOT throw these batteries in the trash.

The main battery (also called the power battery) is the battery pack which allows a laptop or notebook to operate independently of an AC power source. These rechargeable batteries are designed to operate the computer for a certain amount of time (generally 1 to 4 hours). Click here for more info on battery run-time.

CMOS & Clock Backup batteries perform the same function in desktop and laptop computers: when the computer is turned off, the battery maintains the time and date, thus insuring their accuracy when the system is once again restarted. More importantly, the battery saves the computers BIOS setup configuration, which allows the system to efficiently reboot once it is restarted. The computer knows what type of hard drive it is dealing with, etc. Not surprisingly, these batteries are known alternatively as CMOS batteries, Real Time Clock (RTC) batteries, or simply internal batteries.

The most common CMOS battery chemistries are Lithium, Nickel Cadmium (NiCad) and alkaline. They are usually somewhere in the 3 to 7.2 volt range and either solder onto the motherboard or plug in via a snap-in connector (depending upon the computer manufacturers design).

In most cases, replacement of the CMOS battery is an easy task. It is simply a matter of locating the battery on the computer's motherboard, removing it and plugging in a new one. As a rule, internal batteries should be replaced by the same type of battery which was originally used in the machine or according to the manufacturer’s specifications. The major exceptions to this rule are older PCs which were manufactured with a NiCad battery soldered onto the motherboard. These computers usually have a three or four pin male plug, with two of the pins connected via a jumper (this is generally found in the same area of the motherboard as the original battery. This plug gives you the option of leaving the soldered battery in place and replacing it with plug-in lithium or alkaline battery. Removing the jumper tells the computer to ignore the soldered battery and to look to the pins for its power source. If the motherboard has this provision, you can install a standard PC plug-in battery instead of removing the soldered battery and re-soldering a new one. These batteries are interchangeable). A word of warning: some computers have 4 pins on the motherboard, whereas today's plug-in batteries come with a 3 pin connector (one of the pinholes is closed in order to prevent the user from inadvertently plugging the battery in with reversed polarity). If this is the case, you should clip the pin from the motherboard that corresponds to the sealed pinhole on the battery plug. That pin is nonfunctional and by clipping it you ensure that future batteries will not be installed on the motherboard with reversed polarity.

Some notebook computers are designed with a dedicated battery for backing up RAM (random access memory) functions when the machine temporarily loses power from the main battery. This feature allows users to change the main battery pack without losing the current applications and settings residing in memory. This is called a "battery hot swap" - switching the main battery pack without having to turn off the computer.

These types of batteries are alternately known as bridge batteries, RAM batteries and auxiliary batteries or resume batteries.

Most RAM batteries are rechargeable NiCad or NiMH and will last around 2-3 years. It is recommended that you replace your notebook's RAM battery when replacing the CMOS battery

Battery run-time on a laptop is difficult to determine. Actual battery running time depends upon the power demands made by the equipment. The use of the screen, the hard drive and other accessories results in an additional drain upon the battery, effectively reducing its running time. The total run-time of the battery is also dependent upon the design of the equipment. Generally, a new Hi-Capacity™ battery will run 30% to 50% longer than the old battery did when it was new.

NiCad, NiMH and Li-Ion are all fundamentally different technologies and cannot be substituted for one another unless the device has been pre-configured from the factory to accept more than one type of rechargeable battery. The difference between them stems from the fact that each technology requires a different charging pattern to be properly recharged. Therefore, the portable device's charger must be properly configured to handle a given type of rechargeable battery.

Refer to the owner’s manual to find out which rechargeable battery types the particular device supports or use our Quick Find search engine to find the device in our database. The database will automatically list all of the battery types supported by the machine.

Smart batteries have internal circuit boards with smart chips which allow them to communicate with the notebook and monitor battery performance, output voltage and temperature. Smart batteries will generally run 15% longer due to their increased efficiency and also give the computer much more accurate "fuel gauge" capabilities to determine how much battery running time is left before the next recharge is required.