Laptop not recharging

Hello,

I have a gateway laptop and i have a problem :D

I turn the laptop off and it blinks that it is charging but in a couple of minutes or hours while the plug is still intact with the laptop.
the led turns red, which usually means out of battery, whichc confuses me cuz its plugged in and should recharge

for more information
when i turn the laptop on without the battery and with the cord it works fine but, when i put the battery in
it says its charging and its at81 % but after a while again the led turns red and tells me theres only 0% left in my laptop, what is weird is it usually turns of about 10% before when it was properly working but now its at 0 and does not turn off

and thats without the cord on. is it my battery thats out. i got it last february

i need help