TNTom

Hi guys. ive got a bit of a annoying problem with my laptop. i just replaced my old ac adapter as there was a loose connection and you had to have the wire in a certain place for it to charge. now i just bought a new power adapter plugged it in and all was good for about an hour. then all of a sudden the laptop decided to switch it self to battery power then back to ac power then back to battery. so i was like ok this is strange. its seems to b completley random when it does it. sometimes it will go back to ac power othertimes it will stick on battery so i have take out the connecter and plug it back in and it will charge. i thought of maby taking tha battery out all together but then it just cuts out. so im kinda out of ideas. any help would be appreciated thanx.