For most laptop's batteries can last up to 5 years, if lucky up to 8 years like on of my older laptops.

In older laptop models batteries are very easy to remove and replace, in most cases you just take out the battery from the back.

With never laptops in most cases you need to remove the whole bottom cover and then you get access to the battery that is still pretty easy to remove. You just pull one wire and unscrew a couple of screws and you can just swap the battery.