[Rivera42]

One-year-old Dell laptop, Vostro 1500. Have always used it on AC adapter power. Today I decided to run the laptop from battery power so I could work in a different room. Only peripheral connected was a USB wifi card. Using Firefox 3 and Photoshop CS3, no other programs running. The battery died in about an hour. Moreover, although my power settings are supposed to have the system warn me when the battery reaches 30% and shut down when it reaches 15%, I received no notifications at all except for a beep immediately preceding total system shutdown. On retrieving the AC adapter, the computer did not exhibit any additional problems.

I changed the power settings to alert at 35% and hibernate at 25%.

I'm pretty sure this "never been used" battery was supposed to last a few hours at least, I mean after all, this is a "business" notebook.

Why on Earth did it die so fast? Is it time to buy a new battery (or whine to Dell's warranty department)?

[jpoc]

Modern laptop batteries need a period of training when they are new. You need to charge them fully and then discharge them as much as you dare before plugging in the power. While it is certain that yours will have suffered from some deterioration over its year of non use, it should get better if you try training it for a few charge discharge cycles. (Between five and ten should do.)

Why did it suddenly run out without hitting the warnings? Well, the warnings go by measuring the voltage under load and certain voltages will correspond to certain discharge levels with a healthy battery. In your case, I guess that the battery reached its limit of discharge at a higher voltage than for a good one. On reaching the limit, the voltage will then fall away very quickly giving the computer enough time to beep a warning but not to do anything else.

After a period of training, the battery levels reported by the computer should be closer to the actual levels in the battery.

[Rivera42]

I've pretty much never used the laptop on the battery, with the infrequent exception of a power outage or two. When the electricity goes out, however, if I'm on the computer I usually just power-down on the assumption I may need the computer to be available later.

If I do this "training" of the battery, is it likely to help increase the length of time I can run on battery power? An hour is insufficient for anything practical.

[jpoc]

Originally Posted by Rivera42

If I do this "training" of the battery, is it likely to help increase the length of time I can run on battery power?

Yes.

[Rivera42]

Does it make a difference that I'm now powering down with 25% power remaining?