How can I maximise the life of my iPad battery? [duplicate]

Possible Duplicate:
What is the best way to recharge an iPod Touch battery?

Since the iPad battery cannot be replaced, how can I make sure that it lasts as long as possible, preferably years? E.g. should I always keep it charged, or always let the battery run to 0% before recharging?

Note: not the same as How can I make my iPad's battery last longer? which is about battery life during use.

Update: this question looks very much like: What is the best way to recharge an iPod Touch battery? (sorry, only found after posting this). This is slightly more general but perhaps is a duplicate?

According to Apple's website:

Use Your iPad Regularly

For proper reporting of the battery’s state of charge, be sure to go through at least one charge cycle per month (charging the battery to 100% and then completely running it down).