Keep your Mac notebook battery in good shape
9to5mac.com/2010/09/15/keep-your-mac-notebook-battery-in-good-shape
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
We like the look of Watts, a new application from Binary Tricks designed to keep your MacBook or MacBook Pro battery in good shape.
The application will calibrate your laptop battery for you, ensuring accurate battery power display in the indicator and maximizing the gathering and maintenance of battery charge.
As noted by JIm Dalrymple at The Loop, Apple recommends you recalibrate your battery from time-to-time. The application — which is for an Intel Mac notebook running Mac OS X 10.5 – costs $6.95.