what does this red light on my laptop mean?

Depending on the make and model, it's likely an indicator saying that either the power supply (in the wall), the regulator (in the machine) or the batter itself is failing. A failure can also be a bad connection.

1. Shut down the machine properly.

2. If the battery is easy to eject, do so.

3. Using a Q-Tip and rubbing alcohol, CLEAN the copper pads on the battery as well as the pins that connect to them within the docking area of the laptop the batter plugs into.

4. Place the batter back into the machine and test.

If the red light persists, and since you can still use the machine, it's likely to be a dead batter.

Sadly enough, most laptop batteries are not five-n-dime cheap. Go to eBay, Amazon or even a local retailer to compare prices. A local retailer is more preferred as you can take the laptop in and test to ensure it's the cause before finding out the hard way if you have a charging problem, you're stuck with a new battery you didn't need.

Best of luck and hope it helps!

I replaced the battery in my Asus laptop and now I have a red light where the white light was.

this lap top is less than 6 months old why do I need to change batteries ?

If you need a new battery .you can see these online shop http://www.bateriabaratos.es/dell-alienware-m14x.h... .

http://www.cbattery.net/dell-inspiron-1721.html . http://www.askbattery.com/lenovo-thinkpad-edge-e42...