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Boost your battery life: Laptops & netbooks

Posted on 11 Mar 2009 at 16:54

While Lithium-ion batteries don't suffer from the dreaded memory effect of old-fashioned NiMH cells, their performance can still wane if they're not treated correctly. "A battery's average life expectancy is one year," explained Dell's Bob Bennett, "after that it's normal to experience a decrease in battery life."

In fact, a battery can lose up to 20% of its maximum capacity in a year, depending on how it's charged and discharged. What's more, Lithium-ion cells are sensitive to temperature; get them too hot and they begin to lose capacity. On the one hand, keeping your battery charged at a constant 100% is bad because heat and internal resistance will accelerate that steady degradation. According to advice from Apple, it's "important to keep the electrons in it moving properly", and so "Apple does not recommend leaving your portable plugged in all the time". On the other hand, you shouldn't completely discharge your battery too often or - particularly - discharge it then leave your laptop sitting around for a month or two. This runs the risk of sending the battery into a deep discharge state and it may refuse to take all or even any of its optimal charge in future.

Ideally, then, you should cycle your battery on a reasonably regular basis: charging, unplugging and using it, then charging it again. Note that some Lenovo ThinkPad laptops include a Power Manager utility that allows you to set a maximum charge level, ensuring that the battery is never sitting at a constant 100%.

Some people recommend removing the battery when you have the notebook plugged in. In practice, you might not be able to do this - some laptops will only work with the battery in-situ - and it might not be a good idea anyway. You'll lose all your work should someone trip over the power cord, and unless you store your battery at approximately 40% of its capacity at less than 25 degrees centigrade, its performance will degrade slightly anyway. For similar reasons, it's best to cycle between batteries if you have a spare, rather than use one and put one away for a rainy day - that way, you'll get the best from both.

Finally, Intel recommends cleaning your battery: "Rub the battery's metal contacts with rubbing alcohol every two months. Allow to dry before re-inserting."

Switch off Aero

If you're using Vista, switch off the Aero Glass interface. It looks smart, but it's using GPU power to render the effects and wasting energy. Visit the Appearance Settings dialog (Start | Control Panel | Personalisation | Window Colour and Appearance) and change the scheme from Windows Aero to Windows Vista Basic when you're on the go.

Boost your battery life: Smartphones

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Author: Stuart Andrews