In principle I agree, one would think there should be something else wrong to have this many battery problems. However, when I have taken it to the Apple store with battery issues (and only Apple technicians have ever worked on it), they have assured me everything else is fine. Yes, we have checked the Activity Monitor. (I am using Snow Leopard.)
So, either there is something wrong with the computer or the systems that Apple technicians have failed to identify or tell me about, or there is something wrong with the batteries. Neither option leaves me wanting to buy another Mac.
To use an automobile analogy. If you buy a car, and have to replace the battery three times in four years, only to discover there is something wrong that the dealer's own mechanics didn't catch, would you buy that brand of car again?
I didn't think so.
I appreciate antonywu's suggestion for fan control, to look at the multiple discussion boards this seems to be a common and longstanding problem. Thanks too for the suggestion for ThinkPadX1 Carbon, I will check it out.