Pitfalls of purchasing a used (Mac) laptop
Don't get me wrong -- I love my laptop (mostly). I'm currently using a 15" Core 2 Duo Macbook Pro, which I purchased used in May of 2010, at which point it was approximately 2 years old.

Prior to purchasing this laptop, I was using a 13" Macbook:

The new laptop is a step up from the old one in just about every way imaginable:
- Faster processor
- Bigger monitor (Though I've since decided that 15" is the limit of practicality. A 17" laptop is just too much. Not to mention the extra weight, no fun for a commuter like myself)
- Bigger and faster hard drive
- Dvd burner (the Macbook would only burn cd's)
- About twice the ram
For me, the one thing that's fallen short of my expectations is the battery. Effectively, I've found that the battery life is approximately the same as I had with my Macbook, but that's because I wasn't aware of the biggest pitfall of purchasing a used Mac laptop: the batteries are a known issue for customers -- but apparently Apple refuses to admit it. Threads in Apple's support forums tend to live a short lifespan of multiple customer complaints about decreased capacity after a few years or around 200 load cycles, before ultimately being silently deleted.
What it boils down to is that the batteries used in these laptops tend to lose their maximum capacity. My model is rated to charge up to 5600 mAh, and its current maximum charge is approximately 2093 mAh, at least as described by Coconut Battery. I've run multiple battery calibrations, and never seem to get any better perceived battery life, and never notice any improvement in Coconut Battery either.

The important section of the above image is the middle one: Current capacity vs. Design Capacity. With my capacity what it is, I'm able to work unplugged, with brightness turned way down, wifi and bluetooth disabled, sound muted, and peripherals disconnected, for about 90 minutes, depending on what I'm doing.
When I purchased this laptop I wanted to do my due diligence and make sure I wasn't buying a lemon. I tested to verify that...
- Wifi works
- Ethernet works
- DVD burner works
- Bluetooth works
- Trackpad works
- Webcam works
- Built in Microphone works
- Headphone & Microphone jacks work
- Keyboard works ("Pack my box with five dozen liquor jugs")
- USB ports work
- DVI port works
What didn't I check? Battery capacity. And I wish I had known to, because I might have changed my mind or offered less money to cover the purchase of a replacement battery. So this is my warning to you. If you're buying a used Macbook or Macbook Pro, check the battery capacity. Coconut Battery is free and easy to use. Don't make the same mistake I did, or budget to purchase a replacement battery.
in Apple | 12 Responses 2011-04-08 07:45

Guess I need to run the calibration cycle and see if this will bump back up.
My MPB doesn't have a user replaceable battery so I guess in a couple of years it will have to go on a trip to Apple.
Thanks again for the tip!
My original battery capacity is 5200 mAh
My current battery charge is 5069 mAh
I wouldn't necessarily judge your battery by what coconut says. How long does it last on a charge?
For what it's worth, coconut is currently reporting my capacity as 1803 mAh, with a full charge (current charge 1803, max charge 1803, current capacity 1803, design capacity 5600).
Coconut is not an end-all-be-all, and can only provide some form of rough estimation... for sure. But that doesn't mean there is no problem at all.
Take it to the Apple store. Depending on who you get, you might get hooked up. They replaced my entire laptop chassis out of warranty for free one time. They don't get those high customer service rankings for nothing.
-When you see the low battery warning, save your work and close all applications.
Keep your computer turned on until it goes to sleep.
-After your computer goes to sleep, turn it off or allow it to sleep for five hours or longer.
So after the battery is nearly dead and it's gone to sleep, how do I turn it off? Wouldn't the power button just try to wake it back up again?