Improve notebook battery life

Posted on 25 Jan 2006 at 17:01

• 
• 
• 
• 

 1 of 4

Gallery

Time LIne

The one thing you can guarantee is that a li-ion notebook battery will die eventually. From the time they are manufactured, they inevitably deteriorate. Even with the best care, you'll be lucky to get more than five years' use out of one. But if you follow some of the care tips here, you'll find you can as much as double a battery's lifespan.

Keep an eye on your processor Many people don't realise that the more work your processor does, the more power it needs. If you have processes running in the background such as virus checkers, the processor will be occupied more of the time, which increases power consumption irrespective of your power-management settings. Consequently, make sure you don't install too much software willy-nilly that introduces lots of background tasks.

You can easily keep an eye on processor activity by right-clicking on an empty area of the Windows taskbar, selecting Task Manager and clicking the Performance tab. The box labelled CPU Usage gives you the current CPU load as a percentage, and the graph to its right gives you the history over the preceding few minutes. Click on the Options menu in Task Manager and select Hide When Minimized, and you can minimise the window to a System Tray icon that shows the CPU load at all times. If it seems to hover above a few per cent for an extended period, you've got an application running in the background that's draining your battery faster than necessary.

Use Windows XP's power management If you've not already discovered it, the Windows XP Power Management applet can be found in the Control Panel. Just double-click on Power Options. Set the profile to Max Battery and Windows will use the most aggressive power-management settings it can.

Remove unnecessary components Wireless LAN PC Cards can chew through a lot of power, so if you're on the road, pop the card out of its slot when you're not using it. The same goes for other PC Card devices. If you don't take them out, at least make sure they're switched off in software.

Bluetooth adaptors use less power due to their shorter range, so switching them off will have less effect. But switch off when you're not using them anyway, and you'll improve your security too.

Check the BIOS Windows' Power Management applet can't do the best job if power management isn't fully enabled in hardware. Modern Intel-based notebooks with Mobile Pentium processors have SpeedStep technology to slow the processor and reduce its voltage when idle. It's worth checking the notebook's BIOS - by pressing F2 or Del during startup - to see if SpeedStep is enabled.

Turn down the lights The fluorescent backlight of a notebook screen is one of the biggest power drains. Whenever you can, reduce the brightness so you can eke more life out of the battery. Windows' power management does this for you after a certain period of inactivity. If that irritates you, get into the habit of using your notebook's keyboard shortcut to dim the brightness when you're having a break.

Beware of strange potions In What's New, Shopper July 2005, we looked at the BatteryLife Notebook Activator. This is a strip of foil-like adhesive stuff that claims to rejuvenate older batteries when slapped in the side. Our tests showed no improvement. You should treat these seemingly magic devices with caution.

Service charge

Unlike older NiCd and NiMH batteries, li-ion cells are very tolerant of being partially discharged and recharged. You can top up the charge of a li-ion cell without any permanent negative effect on the cell itself.