LAPTOP BATTERIES

“If I was you, I'd view this site - then I would use it as the intro to your next session - it ought to lead to a bunch of discussion”. John Bauman

http://www.pcpitstop.com/pcsafety/video.asp

Details re Lithium ion batteries: http://en.wikipedia.org/wiki/Lithium_ion_battery

Types
lithium-ion (Li-Ion) is the battery of choice

nickel-cadmium (Ni-Cad)

nickel-metal hydride (NiMH).

Care (copied)

• Do not use incompatible computer batteries and chargers. If unsure about whether a replacement battery or charger is compatible, contact the product manufacturer.
• Computer batteries can get hot during normal use. Do not use your computer on your lap.
• Do not use your computer on soft surfaces, such as a sofa, bed or carpet, because it can restrict airflow and cause overheating.
• Do not permit a loose battery to come in contact with metal objects, such as coins, keys or jewelry.
• Do not crush, puncture or put a high degree of pressure on the battery as this can cause an internal short-circuit, resulting in overheating.
• Avoid dropping or bumping the computer. Dropping it, especially on a hard surface, can potentially cause damage to the computer and battery. If you suspect damage contact the manufacturer.
• Do not place the computer in areas that may get very hot.
• Do not get your computer or battery wet. Even though they will dry and appear to operate normally, the circuitry could slowly corrode and pose a safety hazard.
• Follow battery usage, storage and charging guidelines found in the user’s guide.

Some Q& A re batteries (Smart Computing)

Question: How do I know when it's time to replace my laptop battery?

Answer: The main battery in a notebook PC does not last forever and will eventually start to fail after several hundred charge/discharge cycles. If you rarely use the battery (for example, if the laptop is running from the AC adapter), the battery should last for the life of the laptop. But if you're frequently working on the road, expect to replace the battery after about two to three years of regular use. You can tell the battery is failing when its running time becomes unusually short. For example, if you normally get four hours from a full charge, getting only two hours from a full charge might signal battery problems. You can sometimes extend the battery's working life by periodically draining the battery completely and providing a full recharge.

Question: My laptop alerts me only moments before it goes dead. How can I buy myself more time to save files or switch to AC power?
Answer: In WinXP click Start, Control Panel, Performance And Maintenance, and Power Options, and click the Alarms tab. You’ll see two sections: one for Low Battery Alarm and one for Critical Battery Alarm. Make sure that both alarms are activated by selecting the Activate Low Battery Alarm When Power Level Reaches: boxes. Move both sliders to a reasonable level. In most cases setting 10% for a low battery alarm and 3% for a critical battery alarm should yield adequate results.

Question: Is it a good idea to buy a second battery for my laptop, or should I save my money?
Answer: Batteries are electrochemical devices, and they eventually wear out from the stress of repeated charge/discharge cycles. Having additional batteries lets you alternate their use, spreading out the wear and tear across multiple batteries. But batteries can also be costly, so consider your need for mobility before committing your cash. If you're mainly working from AC power at a desk, chances are that you won't need a second battery. However, road warriors who use battery power for several hours at time on a regular basis will definitely benefit from a second charged battery pack—perhaps even a third if you must be mobile for extended periods.

Question: Why does my laptop get less than two hours of use from a charged battery? It used to get about four hours from a charge cycle.

Answer: Check your laptop's power conservation settings. Open the Start menu, access the Control Panel, and select Power Options (in Classic View). While better CPU or graphics co-processor performance might help with gaming or DVD playback, it also uses more battery power. Reset the laptop's power management settings when running on battery power and then check your battery running time again.

If your battery’s life is still short, try a few deep discharge cycles. This means charging the battery fully and then running the laptop until the battery is essentially exhausted. Repeat the full charge/discharge cycle several times and see if that makes a difference. If not, the battery pack itself may simply be nearing the end of its working life and should probably be replaced.