Nowadays a lot of notebook users handle their notebooks like a desktop computer. This means, mostly the device is located on one place and it is always connected with the power supply. But this is not really good for the lifespan of the battery. The manufacturers of the mostly used lithium ion batteries guarantee about 500-1000 load cycles. These load cycles doesn't only contain charging of drained batteries but also these of only partly discharged ones. For example, the self-discharge with a cut-off power supply causes a discharge and when turning on the notebook again it takes a complete load cycle to charge the battery again. 

Li ion laptop battery" by Kristoferb.
Licensed under CC BY-SA 3.0 via Wikimedia Commons

There are two possibilities to avoid that. One possibility is to discharge the battery until 30-40% residual charge and then to charge the battery up to 100 %. The other possibility is to remove the battery from the notebook and to store it in a cool and dry place. It is recommended to do that with a remaining battery load of 40-70%, this means not completely discharged and least of all completely charged. In general, it is important to know, that a high charge condition for a longer time may damage the battery. 
With this proceeding I had a high-capacity battery in my last netbook for four years.