[nasalter]

FYI, Apple have a page providing advice on battery care:

http://www.apple.com/batteries/

One of the things it says is...

"Standard Maintenance

For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month."

[jrockway]

For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally."

I knew I shouldn't have set my air conditioner to absolute zero...

[jacobolus]

I’m not an expert, but I heard in the past that the main reason for this was keeping the battery meter calibrated – so that it could accurately tell you how much battery remained, and how long it would take to drain – more than really for prolonging life.

As far as I know, the information here is still relevant: http://www.macosxhints.com/article.php?story=200303140818432...

In short:

> There is no memory and no scheduled cycling is required to prolong the battery's life.

> The typical life span of a Li-ion battery is two to three years, whether it is used or not.

> The internal resistance of the Li-ion batteries cannot be improved with cycling. The cell oxidation, which causes high resistance, is non-reversible. The electrolyte slowly eats up the positive plate and the electrolyte decays. This chemical change causes the internal resistance to increase. In time, the cell resistance raises to a point where the battery can no longer deliver the energy.