sudden decrease in batter life

I've had my dell inspiron 1420 for about a month or so, and I was getting about 3 to 3.5 hours of battery life until the other day. Then it suddenly changed to about 1:45-2:00 for a full charge.

This is my first laptop. It's running vista. I haven't changed anything, so I don't know why the battery life would change so suddenly (it's still practically brand new). I'm very satisfied with this laptop so far, but this new development is quite annoying.

Could this just be some problems with the way my computer is detecting the battery life and not actually a problem with the battery?

Any suggestions?

 

Have you tried calibrating your battery by letting it completely drain and then charge it back? It might be incorrectly reading the amount of life left.

 

I thought I might need to do something like that, but I've been unable to find the setting to turn off so that the laptop doesn't automatically shutdown when it says the battery is too low.

Anyone know how to do this? I've looked around the power settings in the control panel, but I can't find it.

 

what does having the notebook turn off/not turn off automatically have to do with anything?

 

Well, if my laptop is reading the battery level incorrectly, then doesn't that mean there is more charge in the battery than the computer recognizes? In other words, when the laptop shuts itself down because the battery level is so low, shouldn't there in fact be more charge still in the battery? So if I need to drain the battery completely to recalibrate it or whatever, wouldn't I need to bypass that feature that shuts down the computer, so that it can keep running to drain the battery fully?

I'm new to this stuff, so I may be way off.

 

I don't know what's up, but today when I turned it on fully charged, it said I had about 4 hours of battery life. I used it for a while, turned it off, and now I'm back on it. The meter says 36% remaining and 1:29 left, so it seems pretty normal now.

I guess it might have just been some sort of fluke, but I went through a couple battery cycles where I only got 1:45-2:00 battery life, so it wasn't just a one time thing. I did get a vista update when I shutdown my laptop this morning (before running it on battery), so I don't know if that could have fixed something somehow.

I guess I'll post here again if anything strange happens again.