TBH I read all the instructions when I bought the machine and haven't bothered since. Thats over six months ago and I haven't noticed any degradation in the battery life.
Theoretically you should let it run out about once a month, but I just recharge every morning when checking my desktops. That can be anything from 60 to 13% battery life left depending on how heavily it was used the day before.
My intentions are good......
