DssW has released Battery Guardian for Mac OS X. It helps users know when to deplete their laptop battery. The free app works by placing a small heart in the top-right of the menu bar.

When the time comes to deplete, the heart turns red. This simple and clear indicator makes looking after the battery easy, says Graham Miln, director, Dssw.

He adds that to get the most out of a MacBook battery, it should be depleted once a month. Depleting involves disconnecting the mains power and using the battery until the charge is nearly empty.

Once started, Battery Guardian runs in the background and doesn't require the application to be left running. Battery Guardian will automatically track the battery charge. Each time the battery is depleted, Battery Guardian will reset the reminder.

To download go to http://www.dssw.co.uk/batteryguardian/ . System requirements are Mac OS X 10.6.7 or later.