From the Kenosha News on 2-4-07

Troubleshoot your computer’s battery problems

      If you have a laptop computer, you know how important your battery is.  You may not know that even desktops have batteries and that there are ways to make your laptop battery itself last longer.

      Desktop and most laptop computers have a separate “CMOS battery” whose purpose is to provide power to a chip that stores your computer’s time and system settings.  This allows the computer to keep its clock running even when your computer is disconnected from power.  For more info, see  This site shows various types of CMOS batteries.  I’ve found that most computers have either the “coin cell” type – like a large watch battery about the size of a nickel – or the “1/2 AA” type (not shown on the web site) that is half the length of a AA battery.  If your computer starts “forgetting” some of its settings, check its date and time.  If the year is way off (usually 1980 on Windows and 1956 on a Macintosh), then your CMOS battery is dead.  In a desktop, this is pretty easy to change yourself.  With the computer off and unplugged, locate the battery (1/2 AAs are usually inside of a plastic “cradle” whose top comes off) and remove it.  Purchase a replacement and install it.  On a laptop, the CMOS battery is harder to find and replace.  It is usually the external Lithium type, looking like disks or cylinders shrink-wrapped in plastic with a wire pigtail.  I recommend that you have someone professional replace it for you.

       An excellent resource for all battery issues related to computers is Batteries Plus – a store that specializes in all types of batteries, from watch batteries to car batteries.  They do installation of nearly all of the battery types they sell, and they can even test your car’s electrical system and battery.  (They cannot test laptop batteries, however, because of the risk of explosion.)  A Kenosha store recently opened at 6430 Green Bay Road, in front of Lowe’s.  John, the manager, answered several of my questions about laptop battery care, and told me that they have a handout that provides similar information.   You can also visit  Here are a few tips:

  • Do not leave batteries discharged.  Charge after every use.  You do not need to drain your battery completely and then re-charge; this is only helpful for NiCd batteries, which laptop batteries are not.
  • Leaving a charger connected with the battery installed for long periods can shorten the battery life.
  • If battery life is poor after periods of low usage, let it charge and discharge three to four times to restore the charge.
  • NiCd, NiMH, and Li-Ion batteries are all 100% recyclable.  Look at your battery; the type should be written on it.

       Be aware that your laptop battery may have a shorter warranty than the laptop itself.  While you could purchase a replacement from the computer vendor, a third party brand is usually cheaper.  Most laptop batteries cost between $99 and $169, and there’s currently a $10 promo.  If you call to check price and availability, make sure you have your laptop model number; better yet, take the battery with you to the store.  When your battery is new, charge it for 12-16 hours before use.

By Carol Sabbar from the Kenosha News on 2-4-07