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Apple Notebook Battery FAQ
NOTE: WHILE THE ORIGINAL DATE OF THIS POST IS 2010, THIS POST HAS BEEN AND WILL CONTINUE TO BE UPDATED TO REFLECT CURRENT INFORMATION AVAILABLE ON APPLE NOTEBOOK BATTERIES.
BATTERY INFORMATION
BATTERY LIFE FROM A CHARGE
Apple's advertised claims about battery life from a charge are based on very specific conditions, which are very likely less demanding than your normal use.
- Your battery life is dependent on many factors, including screen brightness, WiFi, bluetooth, apps/processes/widgets running, Flash content on websites, graphics-intensive applications, etc. Even if you're not getting anywhere near the advertised life from a charge, it's most likely quite normal, and simply the result of your usage demands.
- Your "time remaining" indication is an ever-changing estimate, based on the current workload of your system. It will fluctuate up and down from minute to minute as your power demands change. It is not perfectly accurate, but only an estimate.
- If your battery is draining quickly and you're not sure why:
- Launch Activity Monitor
- Click View > "All Processes"
- Click on the "Energy" tab.
- Look at both the "Energy Impact" and "Avg Energy Impact" columns to identify which apps are impacting your battery life. Click on the column headings to sort. Click the same column heading again to reverse the sort.
- Click on the "CPU" tab and sort the "% CPU" column to see what processes are consuming CPU resources. This list will change moment-to-moment as different processes use more or less of the CPU.
screen shot of the entire Activity Monitor window, then scroll down to see the rest of the list, take another screen shot
- Post your screenshots.
- Install ClickToFlash (Safari), Flashblock (Firefox) or FlashBlock (Chrome) to control which Flash content plays on websites.
- Find your Flash version and make sure it's the latest version available.
- Use the YouTube HTML5 Video Player to watch YouTube videos, when available. (May impact fullscreen viewing. See link for details.) Not all YouTube videos are available in HTML5, but when they are, it will reduce power requirements.
- If you're using a 2008-2012, 15-17" dual-GPU MacBook Pro, you can install gfxCardStatus to manually select your integrated GPU, which will help reduce power demands and give you more life on a battery charge.
For more information on graphics switching:
- You may notice the battery in your Apple portable may drain up to 1% per hour (24% per day) while the computer is in sleep mode. This is normal behavior.
- If you find your battery has drained more than around 1% per hour of sleep, it's possible that your Mac didn't stay asleep the whole time. NOTE: Sleep mode is not the same as Standby mode (see next item).
Mac OS X: Why your Mac might not sleep or stay in sleep mode
- MacBook Air models from Late 2010 and newer and MacBook Pros with Retina display (MBPRs) are designed to go into standby mode after an hour of sleep. In standby mode, your battery should last about 30 days. For more information read this: About standby mode
- Which Mac model you have and which version of Mac OS X may be factors in determining battery life.
It is not recommended to run your Mac on the AC adaptor with the battery out (Of course, this only applies to removable batteries).
If the battery is removed from a MacBook or MacBook Pro, the computer will automatically reduce the processor speed. This prevents the computer from shutting down if it demands more power than the A/C adaptor alone can provide.
While you can't remove the new built-in batteries, this method of using both AC power
and battery during periods of peak power demands is still applicable. This is why
you may find your battery may temporarily stop charging or even drain somewhat, even though you have your AC adapter plugged in. This is working as designed and will only be used during periods of peak power demands.
The built-in batteries in the newer Mac unibody notebooks come
pre-calibrated and do not require regular calibration like the removable batteries. For models that require calibration, see the CALIBRATION section below.
Portables with built-in batteries
Current Apple portable computer batteries are pre-calibrated and do not require the calibration procedure outlined in this article. These computers use batteries that should be replaced only by an Apple Authorized Service Provider.
MacBook
- MacBook (13-inch, Late 2009) and later
MacBook Air
- MacBook Air, (all models)
MacBook Pro
- MacBook Pro with Retina display (all models)
- MacBook Pro (13-inch, Mid 2009) and later
- MacBook Pro (15-inch, Mid 2009) and later
- MacBook Pro (17-inch, Early 2009) and later
If you suspect your battery readings are inaccurate, calibration won't harm your battery and will make your readings more accurate.
Be aware that your battery doesn't stop working if the health drops below 80% or if you exceed the number of cycles listed here. You can still use a battery with 79% or lower health or 1001+ cycles, as long as it still holds sufficient charge to meet your needs.
You can use your battery after it reaches its maximum cycle count, but you may notice a reduction in your battery life.
If you have a battery that has failed to meet its expected lifespan, assuming your battery is properly calibrated (for those models that need calibration), you may have a defective battery. If so, contact AppleCare to see if they will replace it.
For the newest generation of batteries (Late 2010 and later):
The built-in battery of your MacBook, MacBook Pro or MacBook Air is designed to deliver up to 1000 full charge and discharge cycles before it reaches 80 percent of its original capacity.
For earlier models:
For Apple notebooks with removable batteries such as previous generation MacBook and MacBook Pro computers a properly maintained battery is designed to retain up to 80% of its original capacity at 300 full charge and discharge cycles. You may choose to replace your battery when it no longer holds sufficient charge to meet your needs.
The built-in battery of the MacBook Air is designed to retain up to 80% of its original capacity at up to 750 full charge and discharge cycles.
The built-in battery in the new 13-, 15-, and 17-inch MacBook Pro is designed to retain up to 80% of its original capacity at up to 1000 full charge and discharge cycles.
CHECKING STATUS AND HEALTH
To check
battery status, use
iStat Pro (free) or
iStat Menus ($16) or
coconutBattery (has some inaccuracy issues) or
Option key + > System Profiler > Hardware > Power > Charge Information: (Snow Leopard and earlier)
Option key + > System Information > Hardware > Power (Lion and later)
Be aware that some of the apps mentioned above may report your battery charge as much as 5-6% different than shown in Apple's battery indicator on the Menu Bar. This is normal, and not a cause for concern.
On the MBPr and on Mountain Lion and later OS X versions, the Menu Bar battery indicator no longer offers "Time Remaining" as an option on the Menu Bar. It still appears in the dropdown menu.
Your battery health is referred to either as a percentage or in mAh and represents your current full charge capacity (mAh) as compared with the ideal full charge capacity (100%). Be aware that
battery readings are not 100% accurate and they fluctuate up and down, so if your brand new battery health is somewhat more or less than 100% or if it fluctuates
up and
down over time (100%, 91%, 95%, etc.), don't worry. It will not only decline. For example, if your battery health is 92% one day, it could be back up to 97% a few days or weeks later.
It is not a one-way fluctuation. This is completely normal.
If your Mac shuts down without a low battery warning, read this:
If you do not receive a warning when your battery has a low charge, generally reported at or under 15%, it may be because the battery menu bar icon is disabled. Please follow these steps to enable the battery status menu item:
- Open System Preferences.
- Click Energy Saver.
- Enable the "Show battery status in menu bar" check box to display the battery status menu item.
Note: Portables using OS X Mavericks v10.9 or later display the low battery warning when the battery has approximately 10 minutes of power remaining. Earlier versions or OS X instead report it at 15% or less.
"Replace Soon" "Replace Now" "Service Battery" "Normal" "Good"
Leopard users may see their battery reported as "Good", while Snow Leopard and later users will see the same condition reported as "Normal". They mean the same thing. For the other conditions introduced in Snow Leopard:
Mac OS X v10.6: About the Battery menu bar extra for portable Macs
It is also
normal that your
battery may not charge to 100%. The battery may appear to stop charging between 93 percent and 99 percent, because the batteries are designed to avoid short discharge/charge cycles in order to prolong the overall life of the battery. When it reaches a full charge, the light on your MagSafe adapter will turn green. This indicates that it has stopped charging your battery and you are now running on A/C power with a fully charged battery.
It will not overcharge your battery. It's also perfectly safe to let your Mac notebook sleep with A/C plugged in.
It's best to use the MagSafe adapter that came with your Mac. You can use a stronger one, but it's not recommended to use a weaker one:
Intel-Based Apple Portables: Identifying the right power adapter and power cord--US
Power adapters for Intel-based Apple portables are available in 45W, 60W, and 85W varieties. Although you should always use the proper wattage adapter for your Apple portable, you can use an adapter of a higher wattage without issue.
For instance If you have a MacBook (13-inch Late 2009) that normally uses a 60W adapter, you can also use an 85W adapter with that computer. You would not use a 45W adapter with that computer; it would not provide enough power for that MacBook. Using an adapter of higher wattage than the adapter that came with the computer will not cause the computer to charge more quickly or otherwise operate any differently than using the adapter that came with the computer.
If you have problems with charging, this might help:
Mac notebooks: Determining battery cycle count
A charge cycle means using all of the batterys power, but that doesnt necessarily mean a single charge. For instance, you could use your notebook for an hour or more one day, using half its charge, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two, so it may take several days to complete a cycle.
So a cycle could be draining the battery all the way and recharging, or draining/recharging it 25% four times, or draining/recharging 10% ten times, etc.
CALIBRATION
The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and
do not require regular calibration like the removable batteries. See the CALIBRATION - NEWER UNIBODY MODELS section above. However, if you suspect your battery readings are inaccurate, calibration won't harm your battery and will make your readings more accurate.
Calibrating is done to keep your battery status reporting as accurate as possible, and should be done the first week you get your Mac or a new battery.
Calibration does not affect your battery health, improve battery performance, or extend battery life. It does make battery condition reporting more accurate, so when your battery reports 97% health, it's more accurate. Without calibration, your battery health could be 60% but still being reported as 95%, for example.
Simply draining the battery and recharging is NOT the same as calibrating. The specific steps for calibrating a notebook battery can be found here:
Apple Portables: Calibrating your computer's battery for best performance
PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), and MacBook Pro (all models)
The battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new battery released with this computer. With these computers, follow these steps to calibrate your battery:
- Plug in the power adapter and fully charge your PowerBook's battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.
- Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
- Disconnect the power adapter while the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, the low battery warning dialog appears on the screen.
- At this point, save your work. Continue to use your computer; when the battery gets very low, the computer will automatically go to sleep.
- Turn off the computer or allow it to sleep for five hours or more.
- Connect the power adapter and leave it connected until the battery is fully charged again.
Tip: When the battery reaches "empty", the computer is forced into sleep mode. The battery actually keeps back a reserve beyond "empty", to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, with the safe sleep function introduced in the PowerBook G4 (15-inch Double-Layer SD) computers, the computer's memory contents have been saved to the hard drive. When power is restored, the computer returns itself to its pre-sleep state using the safe sleep image on the hard drive.
- Yes, you can use your computer while you are charging and discharging your battery.
- If you interrupt the calibration process or feel that you didn't do it properly, it's fine to start over and re-calibrate. You won't hurt anything.
- Caffeine is a helpful app you can use to prevent your computer from going into sleep mode before it drains the battery. Make sure you have saved any work before the battery gets low.
Batteries are not covered by warranty or AppleCare, except in the case of manufacturing defects.
Apple Limited Warranty:
This warranty does not apply:
(f) to consumable parts, such as batteries, unless damage has occurred due to a defect in materials or workmanship;
AppleCare Protection Plan:
b. Limitations. The Plan does not cover:
(ix) Consumable parts, such as batteries, except in respect of battery coverage under APP for iPod or unless failure has occurred due to a defect in materials and workmanship;
AppleCare WILL, however, extend the
defective battery replacement period from 1 to 3 years:
Battery Replacement
Your one-year warranty includes replacement coverage for a defective battery. You can extend your replacement coverage for a defective battery to three years from the date of your notebook purchase with the AppleCare Protection Plan. However, the AppleCare Protection Plan for notebook computers does not cover batteries that have failed or are exhibiting diminished capacity except when the failure or diminished capacity is the result of a manufacturing defect.
Although Apple's official policy is not to replace batteries except in case of defect, there have been cases where an exception was made by an individual Apple representative. If you have a concern about your battery, the best approach is to contact Apple to find what they will do in your particular situation.
If you find your battery bulging or swelling, it is highly recommended that you replace it before it causes damage to your Mac. The bulging or swelling may or may not be due to a defect in the battery. Contact Apple to see if they will offer a replacement.
MacRumors threads about bulging or swelling batteries.
As long as you're running it on battery at least every few days, you'll be fine. Relax and just enjoy using your Apple notebook!
