Although i do usually believe most that Apple says, i do have to disagree here. I used to work for Technuity, LLC otherwise known as Energizer rechargable battery systems. The powerbook batteries as with most laptop batteries now-a-days, are Lithium Ion or for PDAs and some tablets, Lithium Polymer. The nature of Lithium ion is to no be fully discharged after ANY use, especially the first few. When Nickel Cadmium and Nickel Metal Hydride, were used, they experienced the dreading "memory effect" that this article is trying to prevent from happening. The primary ingredients Nickel, and with Sealed LEad acid batteries lead, is the reason for this effect. In lithium batteries, the lithium will not separate from the other elements, so no need to deep cycle your batteries (completly kill before you recharge). You def. kill LI-ION batteries when your do this, however slow it may be.