XPS L1702x won't turn on.

Laptop was running fine. Next time went to use it wouldn't turn on.  I had been getting a message saying battery needed to be replaced - but had ignored because couldn't afford a new one at the moment!  I have tried taking battery out,  holding on button for 10 seconds.  Power adapter light is on.  If I take battery out and plug in it will start up but goes off in seconds.  If I keep battery  in and try nothing.  Please help!  If I need to get a new battery I will just  want to be sure that will solve problems.