How can I maximize the lifespan of my macbook 12 battery

You can keep the computer plugged in while in use.

Keep the computer plugged in whenever possible.

If you keep the computer always plugged in, make sure that at least twice a month

run it on battery until battery charge level drops to about 50-40%.

Please don’t discharge the battery completely. Discharging battery completely will reduce battery health.

Section: Optimizing Battery Life

http://support.apple.com/en-us/HT204054

For more info:

http://batteryuniversity.com/learn/article/**_808c_what_the_user_can_do

http://www.apple.com/batteries/maximizing-performance/

This link has some pretty helpful ideas, including avoiding extreme temperatures, and storing it at half charge in long term storage. Hope that helps 🙂