If you’ve ever had a MacBook Air or MacBook Pro’s battery disappear at random, it can be a disconcerting feeling. This is often accompanied by an “X” in the battery menu, the message “No Batteries Available”, and a very sluggish Mac.
Even after a reboot, the Mac will often have fans running at full speed despite nothing unusual showing up in Activity Monitor. To top it off, the MagSafe charger light typically won’t light up, and the computer won’t sleep. Uh oh…something is terribly wrong, right? Well, sort of — but don’t worry, though; this is all related and it’s a piece of cake to fix.
Before getting into any specifics or the details, let’s cover the solution: a SMC reset.
*Get the Battery Back & Fans Normal By Resetting the SMC*
This is a technical process, but it’s very easy to follow. This will be the same on a MacBook Air and MacBook Pro with Retina, and technically any Mac with a built-in, non-removable battery.
Shut down the MacBook and connect the MagSafe power adapter. Let the Mac completely power down before proceeding any further. Hold Shift + Control + Option + Power concurrently for a few seconds, and then release the Power button as usual to start the MacBook.
Here are the precise key sequences for what an SMC reset looks like on a MacBook Air or a MacBook Pro (Retina) keyboard:
After the Mac has rebooted normally again, things should be all well and good again. Here’s an example of the “No Batteries Available” menu, then after the fix the battery is shown functioning as normal again: Note the total elapsed time in the clock is 2 minutes. In other words, it took only two minutes fix the entire problem, from adding up all the power-related issues, saving an important file or two, shut down the Mac, reset the SMC with the aforementioned keyboard sequence, then reboot the Mac to normalcy again.
The Power Preferences will reset too. It’s important to point out that resetting the SMC will cause you to lose many power-specific options and customizations you may have made to OS X with System Preferences, ranging from screen brightness levels, to settings in Energy Saver for how the Mac handles things like auto-dimming based on lighting and power sources, screen sleep behavior, sleep when idle, etc. Thus, you will have to go back and make those minor power customizations again.
Why does this happen? You won’t always find an exact reason as to why the system management controller goes haywire along with core system and power functions, but the basic idea is that at some point something was corrupted, maybe for a reason or maybe not.
*What is an SMC anyway?*
For those who don’t know, SMC stands for System Management Controller, and it handles power functions and other core hardware roles on Macs, thus inexplicable issues with power management are almost always resolved by resetting the SMC. This is why for problems or oddities with power management like batteries disappearing, refusal to sleep, a very sluggish Mac combined with system fans blazing loudly, graphics cards acting up, are all very classic symptoms of needing to reset the SMC to get things back on track. Take the time to do it; it works.
Having run into this twice on two different Macs in the past week it’s certainly a worthwhile topic to cover, even if it’s a relatively rare problem to deal with. At the very least, it helps to be informed of these kind of things, so if any of the above happens to you, before calling AppleCare or taking a trip to the Genius Bar, take a moment to reset the SMC yourself; it will almost certainly fix the issue completely.
