Remember pal, optimum state for a battery is between 20% and 80% charge level. don't drain your battery too often, and don't keep it charged all the time. my inspiron 15 is also 1 year old but its battery still lasts ~2 hrs
see if it can be replaced under warrenty. also perform a recalibration (full drain followed by ~8 hrs of continuous charge) and check the battery with softs like Batterycare.