How to replace and calibrate your new Macbook battery

Last week I bought a new Macbook battery from the Apple Store to replace the slightly aged one that came with the machine. I’m travelling shortly and I need enough juice to play MAME and Doom do some work while I sit in airports waiting for connecting flights.

Late last week a parcel came for me, my new battery! Here’s how I replaced the old battery and calibrated the new one, with nice pictures.

The Macbook battery compartment is simple to open. Grab a coin, insert into the slot and twist.

Now, why couldn’t they make the iPod battery as easy to replace? Phone covers can be removed to get at the battery and sim card so it’s not a difficult job to do. There’s an interesting iPod battery FAQ here. I expect this question applies to any Lithium Ion battery, not just the iPod’s one.

Q: Is it okay to leave the iPod in the dock, or otherwise attached to external power, for extended periods of time?

A1: Yes. The iPod’s circuitry will no longer charge the battery once it is determined to be full, even if the iPod is still attached to external power.

A2: This can also be a more complicated issue. Lithium ion batteries age faster when stored at full charge. If your usage of the iPod consists almost exclusively of use while plugged in for extended periods of time such as weeks or months, and very limited usage from the battery, the battery is essentially always in a charged state. A fully charged lithium ion battery ages at a faster rate than a lithium ion battery at the optimum storage capacity of approximately 40%. However, keeping an iPod battery near this optimum storage capacity can prove difficult to manage. A lithium ion battery also ages from use, as well as from storage, so the aging effects of constant use of the battery in order to keep the charge closer to 40%, versus constant use while attached to external power, come close to being even.

Once I switched my Macbook on again my new battery was at 39% already and following the official Apple docs:

1. Charge the battery fully until the LED on the power cable goes green.
2. Leave it plugged into mains power for 2 hours. (doing that now)
3. Disconnect mains power and run the laptop off the battery until the machine goes to sleep.
4. Turn off the machine or let it go to sleep for at least 5 hours.
5. Plug the laptop into the mains again and fully charge the battery.

I wonder if calibrating your battery really helps? Has anyone done a controlled test over a length of time to compare two batteries?

I’m not sure why Coconut Battery reports that the “original battery capacity” was 5200mAh. Maybe that refers to my old battery?