I don't have one and I never touch one but the following links should help you out. Generally speaking, ThinkPads are designed very well, but it can vary from model to model especially when it comes to lower end ThinkPads.
I bought an IBM ThinkPad T40 back in 2002/2003 with a Pentium M 1.6GHz CPU. I still works fine to this very day. The battery basically lost half of it's capacity, but lithium batteries do not last forever.