Battery Health

Battery Health

battery_healthBattery life is something everyone deals with, whether it’s a notebook, tablet, or smart phone, and for most people it is always a hassle. I am not writing to tell you the best ways to get the best run times, at least not now. I am writing because what we should do to maximizes the health of the battery so that you can count on your device having a happy battery even beyond the life expectancy of the device once it has surpassed it’s warranty period.

Apple has a lot of great documentation of the basics of battery technology, how to manage power usage, and best practices when using your device. English version is here: and German version: . I check these websites every now and again and I have also made it a habit to send these sites to customers who have just gotten a new battery installed or ask intensive questions about how to utilize their new device to optimise battery performance.

I recommend following Apple’s guidelines of regular calibration and daily recharging because I have seen what happens when you follow those steps and when you don’t. A Lithium-Ion battery has a very simple set up. Your battery has a Full Charge Capacity (Volle Ladekapazität) and a Cycle Count (Anzahl der Zyklen). In OS X you can track these numbers in  > Über diesen Mac > Weitere Informationen … > Systembericht … > and underneath „Hardware“ you’ll select „Stromversorgung“. This is where you can keep an eye on your batteries health and also where your battery icon does it’s math for remaining percentage that you see in your menu bar underneath the battery symbol.


The percentage is a simple equation of Charge Remaining (Verbleibende Ladung, mAh)/ Full Charge Capacity (Volle Ladekapazität, mAh). Depending on model of your computer your battery will ship with a range of mAh as Full Charge value. This value is set by the battery at manufacturing depending on the calibration and chemistry there, heck it can depend on how long it takes from the battery to be manufactured to the time you get the computer in your hands can have an effect on the Full Charge Capacity.

Cycle Count is a fun thing because it shows you how many times your battery has been drained through 100% and back up. As your battery gets used, you are adding to the Cycle Count. What I mean by that is if you used your computer for 5 days and each day you drained your battery by 20% each day and then recharged it that would equal one cycle. If you used your computer without the adapter and used your computer until it died (0%) and charged it up later, that would be a cycle. You could drain your battery 2% for 50 days, that is again 1 cycle. Now everyone is different. as is each day, and so is each battery. You might compare your battery run time with that of your friends and say well his lasts so much longer… But check their battery information and see what the Full Charge Capacity is and how many cycles they have run in comparison.


To get the best out of your battery, use it with the power adapter as much as possible. When on battery power, use the computer only when you need it, and only the necessary programs (rogue/background processes can kill your battery), and keep an eye on your Full Charge Capacity. If you ever notice a Full Charge Capacity that is dramatically lower than what it once was, visit an AASP or Apple Store as soon as possible, they have the necessary diagnostics to thoroughly test the battery and find out the cause of power performance change. To make that even easier the battery icon in the menu bar will also keep you up to date. Should there be an issue it will say „Battery needs service“, „Replace battery“, and in certain circumstance the battery icon will have an „X“ instead of the normal drain or charging icon.

These are the main points I have come up with after seven years of service. Batteries are a tricky thing but the best feeling is having a battery you can rely on in a pinch. Your comments and questions are welcome and I hope this will help more people as time goes on.

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