I read many laptop specifications and find the battery is a 300 cycle rated unit. Let's say you used the battery daily. It may indeed fail in just over a year.
At the office we only use battery power when there is no other choice. You should notice a lot of folk want to use these laptops on battery power but they are going to be upset as they have to replace batteries every year or two.
I have never felt the urge to post on a forum such as this until now. I would say to anyone considering buying a Dell computer - don't bother. I have a Dell laptop which cost around £800. A couple of weeks after the one year warranty ended the (internal built in) battery failed. I did some research and found that many, many people had experienced the same thing, some only weeks after buying the laptop. Curries from whom I'd bought it washed their hands of any responsibility so I contacted Dell. Initially they refused to do anything other than offer to sell me a refurbished battery for £110 !!! + costs to fit it. I refused and said I felt it was a known problem, quoting the many posts I had seen on Dell forums where Dell people had agreed with irate customers that it was indeed a fault. They wouldn't accept it was a fault and refused to do more than sell me another battery. I said if that was the case I would contact every TV & newspaper consumer protection programme I could find and try to publicise the situation. They then said that as a 'gesture' they would send out a technician the next day to fit a battery. This worked for around 2 months until I noticed the battery wasn't charging even when powered from the mains electricity. I contacted Dell who did some tests and said I needed a new Motherboard at a cost of £650!!! I told them I wasn't willing to accept that on a computer that was a little over a year old and went down the bad publicity route again. The said as a gesture they would sell me an extended warranty for £125 which would mean I'd get a motherboard fitted. I felt I had little choice so accepted. They came out this week & fitted a (re-conditioned) Motherboard. As a result of doing that my keyboard then did not work so they arranged for someone to come another day to fit one. That was done, it still didn't work and the technician said it was a faulty motherboard that had been fitted first time and it would have to be replaced. Interspereced throughout all this were numerous calls to Dell customer support (what a joke). Left on hold for periods of 25/30 minutes, promises of call back that never happened. I eventually mailed Dell's Technical Support Director who promised me that one of his/her senior people would contact me within 4 hours and he/she would personally keep an eye on the situation until it was resolved. That was 8 hours ago and I've heard nothing. I don't think I can adequately find the words to fully convey what a monumentally miserable and frustrating experience this has been!