Feb 23 2007

Get More Life Out of Your Netbook Battery

Getting the most out of notebook batteries isn't intuitive, but it is pretty easy.


Get More Life Out of Your Notebook Battery

Do You Want to get more life out of your notebook computer? It has a lot to do with battery best practices.


Today, most notebooks use lithium-ion batteries. Li-Ion batteries are 25 percent lighter and environmentally safer than nickel metal hydride batteries, which in turn offer double the capacity and are more eco-friendly than nickel-cadmium batteries. Although Li-Ion batteries are most common, you can still find systems juiced by NiMH and NiCad batteries.

Getting More Shelf Life

Li-Ion batteries are fairly easy to deal with and much more forgiving than earlier rechargeables. When you get a new Li-Ion battery, fully charge and discharge it a few times to condition the battery prior to pressing it into service. After that, discharge the battery partially in normal use and then recharge it. Li-Ion batteries don’t have a memory, as NiCad and NiMH batteries do, so they don’t lose storage capacity from partial recharges.

But don’t leave a Li-Ion battery plugged in all the time as it may overheat. If you’re not using your notebook on battery power every day, there’s no need to keep it loaded. Simply remove the battery from the notebook when you’re on AC power. When stored, leave the Li-Ion battery with only a 50 percent charge to prevent losing battery capacity. If you store the battery for an extended period, it’s a good idea to discharge and recharge the battery once a month and then again when you return the battery to service.


Got a cell phone or digital camera with Li-Ion batteries?

The same maintenance tips apply: Keep them cool and plan on changing them every couple of years.

Li-Ion batteries last longer and retain more of their original capacity if you keep them cool. The life of a Li-Ion battery is about 18 to 24 months under normal circumstances, regardless of how much you use it, after which the battery may not hold an adequate charge. Shelf life is important: Buying last year’s notebook may give you a battery that’s only good for another six to 12 months. Don’t buy a Li-Ion battery until you’re ready to use it.


What About Safety?

It’s important to train users about proper care, says Merrick Bechini, information systems director for the Society for Technical Communication in Arlington, Va. “The biggest things have been being consistent about recharging the batteries and taking care not to keep them in a car on a hot day,” he says. “Mostly, I just want to prevent them from being abused.”


Get More Life Out of Your Notebook Battery
Photo: Randall Scott
Merrick Bechini of the Society for Technical Communication says users need training on how to properly care for Li-Ion batteries.

Li-Ion batteries have built-in protection circuits to prevent overcharging and overheating. But there’s still the potential for thermal runaway, a condition in which a battery can become extremely hot, vent gases and catch on fire. Thermal runaway is a chemical reaction within the battery’s cells and can occur even if the battery is completely discharged. Li-Ion batteries aren’t the only batteries that can catch on fire from overheating: NiCads and NiMHs can do it during charging.


Although you’re 1,000 times as likely to have your identity stolen as have your battery catch fire, any Li-Ion battery can overheat if mistreated. Users don’t need to treat these batteries like unexploded bombs, but a modicum of care is in order.

• Keep batteries away from freezing temperatures or extreme heat, direct sunlight, rain or excessive moisture. Don’t leave them in a car or trunk during the summer.

• Don’t short-circuit, drop, dent or puncture batteries — all of these can trigger thermal runaway.

• Avoid static shocks, which can destroy the battery’s protection circuits.

• Use approved charging devices and don’t overcharge. The wrong charging device can damage the protection circuits and lead to overheating.

Scott Lowe says his biggest problem with batteries has been people’s perceptions about handling them. “After [last year’s] battery recall, a lot of people didn’t want to risk anything with their computers,” says Lowe, CIO of Westminster College in Fulton, Mo. “We got the serial numbers for all the college’s notebook batteries to tell people if they were affected, and students would come to the help desk to check the batteries on their personal computers. As it turned out, we didn’t have to return any batteries, but more than a handful of the students did.”

On the Horizon

Meanwhile, companies are developing new Li-Ion batteries. Last year, Altair Nanotechnologies unveiled a prototype battery with an estimated 20-year life that can operate in extreme temperatures, has triple the capacity of a standard Li-Ion battery and can charge in six minutes.

A123Systems, Matsushita Electric Works and Toshiba have made similar announcements about their plans to produce lithium batteries that are more powerful, faster and safer to use. These companies have initial models in testing or limited release.

By the time you need to buy new batteries for your equipment, you’ll probably have a wider range of options.

CEO Takeaway
Although NiCad and NiMH batteries still have many applications in various types of equipment, Li-Ion batteries are used for virtually all notebooks sold today. They’re light, don’t require as much care as nickel-based batteries and do a good job of retaining storage capacity. But even these batteries require basic maintenance:

•Remove the battery when you’re not going to use it for a short period, such as when you're flying or for long periods when you’re running on AC.
•Buy a case to protect the battery and the notebook from wear and hard knocks.