my lenovo thinkpad r500 wont turn on unless its plugged in

[jerrybrown084274]

I was browsing on my laptop and it suddenly went off without warning so I plugged in the charger and turned it on but it shows plugged in(not charging) and when I uplug it goes off immediately. Please I need help asap

 

[RARRAF]

probably means the laptop battery is dead look for another one same model as old battery or one your system will support

 

[geofelt]

The battery is likely bad.
Plan on replacing it with a legitimate Lenovo oem replacement.
Yes, that will cost more, but there is some circuitry in a battery and generic replacements are not guaranteed to work.