Calibrate as often as suggest and you should have a health battery.
For current models, this is "never." Calibrating and maintaining the battery are two different things. Current (non-removable) batteries cannot be calibrated. They should be used at least occasionally, but not drained completely unless you have no alternative.
Well there you go. Has been a while since i have gone to there pages. Thanks for that. Will now know when i get my next non-removable battery Mac.