E6410 Charging problem

Hello everybody, i have some problems with the charger, it's a new one ( bought 2 months ago, and it's original) so was working fine..no problems till today when i connected to the laptop and now it's charging like 5-10 minutes then 15-20 minutes won't charge...just charge 2 seconds then it disconnect, i'm afraid of what's going on...Please help me, i want to buy a new charger but i want to be sure that the charger is the problem and not something from laptop..

Have a nice day people !