There are a plethora of myths about batteries. Lithium-ion or Nickel-based batteries, they all share one thing in common – charge cycles. Apple’s definition of ‘charge cycles’ can be found at Apple’s Lithium-ion Battery care page and it goes something like this:
“…using all of the battery’s power, but that doesn’t necessarily mean a single charge. For instance, you could listen to your iPod for a few hours one day, using half its power, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two, so you may take several days to complete a cycle. Each time you complete a charge cycle, it diminishes battery capacity slightly, but you can put both notebook and iPod batteries through many charge cycles before they will only hold 80% of original battery capacity.”
How does this information affect Mac portable users?
Each Mac system comes with Apple’s limited warranty on the batteries that come with each unit and the warranty is only good if the battery fails, within a decided charge cycle range. Once your battery exceeds this decided number of charge cycles, the warranty ceases to be effective.
So, its in the best interest of all Mac portable users to keep charge cycles low. Despite the myth that running the battery totally flat before re-charging does the battery good; Apple’s, lesser publicised, charge cycle policy tends to encourage the inverse behaviour. Whether this is good for a battery’s longevity is unknown but its generally never good to always run batteries flat all the time.
The next question that begs to be asked is, “so, where do we find our Mac portable battery’s charge cycle count?”
Your Mac portable’s battery charge cycle count can be found within your Mac’s System Profiler application. Which can be accessed either by:
- clicking the Apple logo in the top left hand corner of your Mac OS X screen; then click ‘About This Mac’, followed by ‘More Info’ or;
- launching the System Profiler application from within your /Applications/Utilities/ folder
System Profiler is divided into a Contents section on the left and the info pane on the right. Charge cycles can be found by clicking the ‘Power’ option in the System Profiler’s Contents section.
In conclusion, its probably a good practice to begin recharging your Mac portable’s battery once the battery indicator displays a remaining charge that’s hovering around the 10% – 15% mark. As for the magic number of charge cycles before Apple ceases to cover the battery under its limited warranty; that’s still pretty much under wraps. In general, notwithstanding the best care that can be provided, Mac portable batteries have an average lifespan of around 2 years, going on daily average use, where the Mac portable is put to sleep more often than its shutdown completely.