For lithium ion / polymer (which all our notebooks are), there is no memory, i. e., you don't have to wait for it to completly discharge.

i don't know any real way to lengthen your battery life, possibly not using it will make it last longer, but somebody else posted that that doesn't really help either...

There are so much conflicting information out there, but with those who can really provide explanations for their reasons and recommendations, I drew the following conclusion for myself:

Disclaimer: I'm NOT an expert in battery, chemistry.

- Lithium rechargeable batteries do NOT have memory effect. (From what I know, memory effects do NOT appear in ANY battery chemistry and is almost only producible in lab environments and was originally found in satellite batteries. Nonetheless, people generally refer all types of battery degradation to "memory effect".)
- Lithium rechargeables prefer SHALLOW discharges, so charge yours whenever possible.
- Do NOT cycle your lithium batteries for the sake of prolonging its life, it will kill you battery faster instead (for the reason above).
- Lithium and all other rechargeables batteries WILL degrade overtime, you just can't expect them to last forever. Li-Ion batteries usually have a few years of shelf life, that means no matter you use it or not over a few years it WILL die. Li-Ion batteries' performance also degrades with usage, more usage, shorter life.
- Lithium rechargeables, if not used for a long period, should be stored at a low temperature with 40% charge.

FYI: http://www.buchmann.ca/Chap10-page6.asp