I never give the battery in my laptop much thought. I charge it when I need to and forget about it. That changed a couple of weeks ago when I couldn't get to the Web at home, and was reduced to working at an Internet café. Since there's lots of competition for seats with power outlets here in blogger-heavy San Francisco, I made sure my laptop was charged before I left the house.
Ooops. Ten minutes of use and my PC shut down. It was out of power. I charged it again, same thing happened. Yes, the battery was DOA. Humble as a battery may be, you won't get much work done without a good one.
After shelling out for a new one, I asked around and found a battery expert who has some solid tips on how to give laptop batteries a long and energy-rich life.
1. Keep the Laptop Off Your Lap
"Batteries like to be at room temperature, and I don't mean like a room in the tropics," says John Wozniak, a distinguished technologist for Hewlett-Packard.
Although most of us call our portable PCs laptops, today's high-performance notebooks aren't designed to sit on your lap. Sure, they get warm and you may start to feel uncomfortable after a while, but that's not the point. Most laptops have little legs on the bottom, designed to let a bit of air flow underneath. When you're working on a hard surface, like a desk, there's no problem, but when the notebook sits on your lap, it sinks down a bit and air can't circulate.
That can become a real issue rather quickly if you're watching a movie, since playing a DVD keeps both the CPU and the graphics chips busy and running fairly warm. You can avoid the problem by working on the folding tray if you're flying, or spending $20 or so on a pad stiff enough to give the laptop a bit of clearance.
Keeping the vents on your laptop clean does a lot to keep heat from building up. A simple, but effective method is to buy a can of compressed air from any computer shop or hardware store and blow out the dust.
2. A Little Unplugging Helps
Not so long ago, most laptop batteries were NiCads, that is, nickel cadmium based. That design had a fairly major flaw: if the battery was consistently charged before running most of the way down, it would no longer take a full charge, no matter how long it was plugged in. That was called battery memory, and the solution was to drain them every now and then and be sure they got a full charge.
Today's lithium ion batteries don't have that problem, so don't worry about recharging before the power gauge is hovering near empty, says Wozniak.
However, leaving them plugged in all the time isn't a good idea either, although it's tempting. In effect, the battery gives the user an uninterruptible power supply, so if you expect the electricity to go off unexpectedly, it makes sense to keep the battery in place when the machine is plugged in.
But do that too much, and your battery will degrade. So remove it if you don't plan to work unplugged for an extended period of time. The best way to store a lithium ion battery is to let it drop to about 60 percent of its charge and be sure you keep it in a reasonably cool place, he says.
3. Understand the Specs
Remember, battery technology doesn't follow Moore's Law. Having covered the technology industry for quite a while now, I've heard many promises that a real breakthrough in battery technology was coming. Well, it hasn't—and Wozniak says he doesn't see one on the horizon.
That's not to say batteries haven't improved; they have, with gains of about 6 percent to 8 percent per year, he adds.
Generally speaking, more cells per battery mean more power, but that doesn't mean a 12-cell battery will give you 33 percent more running time than a nine-call battery. For example, a 9-cell battery rated 3.0 amp hours has just about the same energy as a 12-cell battery rated at 2.2 amp hours.
Rather than do the math, it's simpler to check the specs and compare the number of watts, an easier number to find. As you'd guess, the actual run time a battery will yield is dependant on what the notebook is doing. Applications like video use a lot more juice than writing or surfing the Web, of course.
No electronics product will last forever, but treated well, your battery hang in there for at least two or three years.
San Francisco journalist Bill Snyder writes frequently about business and technology. He welcomes your comments and suggestions. Reach him at email@example.com
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