how many days does your mobile battery work without recharging?

The battery is supposed to work a couple of days? Mine won't even last a day! I am lucky if the darn thing lasts longer then two hours! What the heck! Of course my phone is almost four years old and I had a friend tell me that cell batteries have a life span of only four years. Does anyone know if that is true? Please give me feedback on that! Thanks!

Well, it depends of how much i talk in it, and how many SMS i recieve and send! But i think it should be able to work without recharging, if theres no calls, and sms, in about 3 days! I havn't tryed if it's true, cause efter night i plug it in, so every morning it have full battery!