After reading Long Live Your Laptop Battery, where I advised readers to remove their Laptop's battery when using AC power, John Stevens asked if he needed a UPS.
In that article, I recommended removing the battery if you're going to keep the laptop plugged in over an extended period of time--say, a week or more--to limit wear and tear on the battery. It also helps keep the battery and the laptop from overheating.
I admit that when I wrote that article, I didn't think about the UPS question. I live in an area where power outages are rare, and I've never felt the need for a UPS myself--even with a desktop. I also tend to save my work frequently, so that a sudden stop--whether from a power outage or a Blue Screen of Death--won't lose me much work.
But if you feel you need full protection against power outages, you should either ignore my advice and keep the battery in the laptop, or buy a UPS. To help you consider the right course of action, compare the price of a UPS against that of a replacement battery for your particular model. But remember that buying a UPS is a definite expense, while running the risk of possibly having to replace your battery is only a possible expense.
Contributing Editor Lincoln Spector writes about technology and cinema. Email your tech questions to him at email@example.com, or post them to a community of helpful folks on the PCW Answer Line forum. Follow Lincoln on Twitter.