What is the full charge capacity design value?

Such a simple question which has a very complex answer ;-}

There are quite a few variables that impact the batteries lifespan. The easiest way is to use an app which can to its ability give you some guidance. This is what I use: coconutBattery it is by far one of the best tools out there to monitor your batteries health.

Some of the important tricks to lengthen the batteries life is to try not to store the system with a full battery if you are not planing on using it for a week or more. Don't fully discharge the battery and leave it in that state very long. Monitor your cycles getting to 800 to 900 is about the limit of most batteries. Thats not to say you couldn't have a failure sooner or get more cycles than that.

Extreme heat & cold effect the batteries lifespan as well.