Extend the life of your laptop’s battery

Fred langa By Fred Langa

With proper care and feeding, the expensive lithium-ion batteries in your notebook PCs and other portable gear can run well for many, many years.

On the other hand, common battery-care mistakes will reduce your batteries’ run times and lead to needless and costly early replacement.


The care and feeding of laptop batteries

A reader named Rick got a new laptop for the holidays and is wondering how to maximize the life of its expensive batteries:
  • “I just got a new laptop with Windows 7 for Christmas. The new laptop has a 6-cell lithium-ion battery. How can I get the most life from my new laptop’s battery and make it last the longest?

    “Should I periodically charge and then use/drain the battery? Should I leave the battery in the laptop even when I’m using the AC plug? Will heat from the laptop when it’s plugged into AC affect the lithium battery?”

Excellent questions, Rick!

Heat is the enemy of lithium-ion (Li-ion) batteries. When your laptop runs on AC, it’s smart to remove the battery pack and store it in a cool place. Low temperatures forestall the inevitable and irreversible chemical changes that occur in Li-ion batteries.

In fact — and this will sound odd — if your laptop is mostly run off household AC power, you can greatly extend the life of its Li-ion battery this way: Run the battery down to about 40% of maximum charge, remove it, and store it in a tightly wrapped plastic bag inside your refrigerator! Storage at about 40 degrees F (4 to 5 degrees C) is ideal. Think of it as the 40-40 rule: 40% charge, 40 degrees F.

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All Windows Secrets articles posted on 2010-01-21:

Fred Langa

About Fred Langa

Fred Langa is senior editor. His LangaList Newsletter merged with Windows Secrets on Nov. 16, 2006. Prior to that, Fred was editor of Byte Magazine (1987 to 1991) and editorial director of CMP Media (1991 to 1996), overseeing Windows Magazine and others.