Screen dims when using the battery

Mine isn't a Dell, its a Gateway. But my understanding is that just about every laptop/notebook is designed with this fature. Its a baterry saver. You can go into your controls/settings and change it...but it will drastically effect the length of your battery life. When I turn mine down(less power, less light...) I get about 2 to 3 hours of battery power. If I turn it up to match when it is plugged in I get about an hour to an hour and a half.

My Dell does that as well, and I suggest it's a feature, not a design flaw; the idea is that when you're off mains power, it's trying to run things at a reasonably reduced cost to prolong battery life. Therefore the screen is dimmed a little, as opposed to the power failing 30 minutes earlier. My subnotebook does the same, but only when the power is getting low. I think this is pretty standard with laptops now: A similar thing which had me worried was I could never feel the fan running all the time, unless it felt really hot. My previous laptop was old, and had a fan which ran constantly and sounded like a vacuum cleaner. It took a while to occur to me that the new one would only run the fan when the internal workings actually needed cooling ;)

It is normal for you PC to dim when you are use battery only,the advantage is save you battery in order to use PC longer! especially when some emergency situaion, it's good for people to save battery to last a litlle longer.But if you insist,you can use power not battery.