Laptop battery not working..

Always post your model name and operating system. Also you should mention how old the computer battery is. I'm not sure what you mean when you say you plugged the battery into the laptop while the computer was plugged in.

When I have it plugged into the outlet plug.  It's a Dell Inspiron 1750 Core 2 Duo, T6600. The battery is a 9 cell battery.

It's Windows Vista Business operating system.

I suggest that you try another battery and/or try this battery in another laptop.  It would seem that your battery is at fault and you can get one from Ebay for about $20.

still need help with this

Apparently this is a common problem with Dell.  I have  a similar problem and have found many people online who do as well.  I have a Dell XPS L502X laptop running Windows 7 Ultimate, i7 2720QM CPU, 8 GB RAM, 256 GB Samsung PM810 SSD.  A few weeks ago I would occasionally get an error when I plugged in my power adapter that the AC power adapter type could not be determined.  At first I assumed I had not made a good connection when I plugged it in.  Making sure the plug was fully inserted would correct the problem.  Then one day last week that stopped working.  Now I don't have enough battery charge to run without the adapter and it does not charge the battery..  The battery passes the system tests so I am assuming my power adapter has gone bad.  Is there a way to check the power adapter to make sure that is the problem?

Hi,

Welcome to dell community forum.

Kindly check with another wall outlet first .If that doesn’t work remove the battery from the computer and connect the adapter and check if the computer works. If  the computer works fine  with the adapter connected the issue is not with the adapter might be an issues with the motherboard.

Try to do a bios update:  http://dell.to/KaVrrI

Warranty status: http://dell.to/zEE2Cm

If you have active warranty, you can contact me directly by clicking on my user name, add me as your friend, and send me the system service tag, phone # with address.

This seems to be a long standing problem and contravenes the Durability aspect of the 1979 Sale of Goods act.

Especially as many complaints are within a 6 month period and it really is a gamble as to the date your laptop fails to work as it should.