My laptop running on BATTERY and giving error 'No battery detected'

my battery was giving 1.5 hour power backup from last 4 months... then last month it decreased to 1 hour...from couple of days it decreased to 1/5 hour(with error 'Consider replacing new battery') and yesterday i was using on battery power... and battery had 34% power remaining.. suddenly battery indicating light turns orange and pc shutdown... after that.. my pc is not charging battery... and if i run pc on battery.. it work 10 to 15 minutes ( with orange light.. and on task bar.. battery icon giving error "No battery is detected" ) and then shut down.

today i run laptop on battery power and open setup..and there was error "No battery installed" in battery info...

what happened.. can anyone tell me????

i forgot to tell you that... according to battery's LEDs.... my battery is healthy enough.. but now only 1 led is working...

Your battery has failed and must be replaced. They're only good for three or four years. Happens to all laptops.

Thanks for advice, now i realize that i have to buy new one.