Unless you are sitting on the couch using your mouse for the tv display, buy a plain old wired optical one. You can get an inexpensive mouse with all the bells and whistles now. I bought a good GE one at Target for $13 and a MS one at Office Depot for less than $20. You must spend that on batteries now. PS Have you ever consided the mouse is defective? If you are still under warranty, have Dell send you a new one.

That's fairly typical for some battery powerd mice.  I've heard some take the batteries out at night or if they are not going to use it for a long period. 

Unless you need it for "remote" operation, I agree a wired optical mouse is the best option.

Thanks for all the tips.  Because of the stupid short mouse cords on alot of the corded mice and the set up I have to have with my computer desk, (distance vs. cord length)  I have to yank and pull at a corded mouse all the time.  I love my wireless mouse.  I may just upgrade to another type of wireless and see what happens.  Since the one I have at work is a different brand and doesn't have the same problem, though it stays on all the time too, I believe it's the quality of the mouse.  Regardless, the rechargable batteries are a great bonus,  I always have a spare set charging up for when I need them.

Thanks to all for the quick replies!

About once a month is normal since the LED is on all the time. You could remove the battery, but that's not real convienent. With rechargeables your cost is zero after buying the batteries. The convienence of not having the mouse cord wrap around everything and getting hung up on my keybosrd drawer is worth it.

What brand is your work mouse? Does the LED shut off after a period of no use or is it just less hungry?

I have a Microsoft wireless mouse at work. Nothing fancy, just the basic.  The light stays on non-stop.  Probably just less power hungry than the Dell.

Be sure that when you're not using the mouse, it's sitting on a light colored, but not reflective, surface. That provides the best opportunity for the rodent to go into sleep mode and conserve battery.

For your rechargeble batteries, pay attention to the power rating. Less expensive ones have less capacity (in general). Look for ones rated in the 1800mAh or better ranges.

Having a quality charger, that can do a conditioning charge once in a while, adds to any NiCd or NiMh battery life. About every 10th charge the battery should be deep discharged (conditioned). (Don't do this with your Lion batteries.)

Val