Service Battery Warning on Mac – Do You Need to Replace the Battery?
The most dreaded alert a MacBook user can ever see is the one that says “Service Battery”. As with all laptop computers, the battery is one of the most critical (and expensive) components, and it is also a component that essentially cannot be serviced, despite the name of the alert. When a lithium-ion battery is done, it’s done, and either it has to be replaced or the laptop becomes a desktop, requiring a plugged-in connection at all times.
But is the “Service Battery” warning really a trump of doom for your beloved MacBook? Or do you have options? In this article, I will explain how the lithium ion batteries in your MacBook work, how to get the best performance and longest life out of them, and give you some suggestions on ways to resolve the “Service Battery” alert that don’t require you to shell out for a new battery pack.
How Lithium-Ion Batteries Work
- How Lithium-Ion Batteries Work
- What To Expect from MacBook Batteries
- Service Battery Warning on Mac
- Reset the Service Battery Warning on Mac
- Reset SMC to stop Service Battery Warning on Mac
- Other Ways to Address the Service Battery Warning on Mac
- How to Extend Battery Life
The basic chemistry of the lithium-ion battery was discovered by an American chemist named Gilbert Lewis, way back in 1812. All chemical batteries work on the same basic principle: a positive electrode (cathode) is separated from a negative electrode (anode) by a solution called an electrolyte. When the battery is connected to an electrical circuit that draws power, electrons flow from the anode to the cathode, creating a current.
If a battery is rechargeable, then this flow can be reversed. When a current is sent into the battery, electrons flow from the positive to the negative electrode, recharging the battery and adding power to it. In a lithium-ion battery, the positive electrode is usually made out of lithium-cobalt oxide (LiCoO2). Newer batteries use lithium iron phosphate (LiFePO4) instead.
You have undoubtedly heard news stories about lithium batteries exploding or catching fire. Those stories are true; this type of battery is subject to overheating and exploding if they are not carefully monitored. As battery technology has developed, this problem has been more or less eliminated by the addition of electronic monitoring circuitry added to a battery. This circuitry keeps an (electronic) eye on the discharge rate of the battery. If something goes awry (usually a runaway discharge), the circuit shuts down the connection between the anode and cathode and stops the reaction in its tracks. No reaction, no fire, no explosion.
There are many variations on this basic battery design, with different designs producing different power outputs, reliability levels, and so on. The main factor we are looking at today is the charging life cycle of the battery; that is, how many times can the battery be discharged and then recharged, before it no longer functions at full capacity. The cathode slowly degrades over time as its molecules keep getting put through the wringer, and eventually the battery reaches a point where it stops holding as much of a charge and then eventually it will not hold a charge at all. For lithium-ion batteries, the number of cycles before this happens varies widely depending on the quality of the battery build and the level of discharge that the battery supports.
What To Expect from MacBook Batteries
The batteries in your MacBook follow the same physical laws as all the other applications for lithium-ion batteries. Laptops don’t draw a whole lot of power, and are generally designed to optimize their power consumption. Even with those two facts in mind, a typical recent MacBook or MacBook Pro can run for about 10 hours of using the Internet and doing normal computing tasks like word processing or playing music. The battery life will be shorter if you are doing intensive work like calculating pi or doing chemistry equations. Older MacBook models generally run for about 8 hours on the battery.
How long can you expect that level of performance from your battery? Apple states that its new batteries are designed to support 1,000 full charge-discharge cycles, after which the battery should still have 80 percent or more of its original capacity. Note that even after this long life-cycle (a complete discharge and recharge every day for three years), your battery will still work – it just won’t have the same ability to hold a charge as it did at the peak. It will continue to degrade slowly over time and will eventually stop working altogether, but that can be years after it reaches its nominal end of life.
Note that the Mac OS is quite intelligent when calculating cycles. Partial charges do not count as a complete cycle; if you discharge your battery a bit and then charge it back up, that will only count as a fraction of a cycle for its internal monitoring. You can find the complete list of expected cycle counts for Apple batteries at this page on the Apple website.
Service Battery Warning on Mac
Your MacBook monitors the health of its battery, using its original capability as a base. If you mouse over your battery icon on the status bar at the top of your screen, a popup will display the battery status, the amount of power remaining, and a list of apps that are using a lot of power. There are four battery status messages.
- Normal – This battery status means that your battery is operating within normal parameters and is basically “like new”
- Replace Soon – The battery is holding less of a charge than it did when it was new, but is still working fine.
- Replace Now – The battery still works normally, but has significantly less ability to hold a charge than when it was new. It’s time to start looking for a new battery.
- Service Battery – There is something wrong with the battery’s function. It may still be working, and you won’t hurt your computer by continuing to use it, but the battery may not hold a charge for long at all.
The first thing you should do when you get a “Service Battery” notification is check the System Report. This will tell you the cycle count and overall condition of your MacBook battery. To view the System Report:
- Select the Apple Menu (the Apple icon in the top left of your computer), then “About This Mac.”
- Select “System Report…” and then “Power.”
- Check the “Cycle Count” of the battery.
Reset the Service Battery Warning on Mac
If you get the Service Battery warning, your MacBook is old, and you’ve got 2,500 cycles on it, well, it’s probably about to die. Things wear out.
But if your cycles are relatively low, then there may be other issues at play and you should use the methods I’m about to describe to try and resolve the issue yourself, before you take your wallet down to the Apple Store and buy another round of lattes for the boys and girls in Cupertino.
The first thing to try is to recalibrate the battery. Recalibrating the battery basically means discharging it completely (something that most of us rarely do) and then recharging it completely so that the battery management circuitry inside your MacBook has a chance to see the entire range of possible charge in the battery. Battery recalibration takes a day or so, so if possible, do it over a weekend when you don’t have to have your MacBook for work. Here’s how to do it:
- Fully charge your MacBook to 100% – until the MagSafe light ring goes green or the drop-down from the battery icon indicates that your MacBook is fully charged.
- Keep the laptop running while connected to the power supply for a couple of hours.
- Unplug the MacBook from the power supply, but leave it running. You can use it normally, or just leave it on. Run processor-intensive programs to speed up the process if you wish.
- When you see the low battery warning, save any work you are doing.
- Allow the MacBook to run until it shuts down due to lack of power.
- Leave the MacBook overnight with no power.
- Charge the MacBook again the next morning until it is full.
Your MacBook should now be able to more accurately gauge the battery status. If this clears up whatever the problem was, your Service Battery warning should go away. In addition, you’ll notice that your Mac OS battery indicator now gives a more accurate reading of the battery’s status – no more surprise losses of power.
Reset SMC to stop Service Battery Warning on Mac
The next thing to try is resetting your System Management Controller (SMC). This is a hardware chip that controls some hardware settings, including the power system. While very reliable, it can occasionally have issues which require a reset. The process is straightforward, but any customizations to your power plans or hardware settings may also be reset. Here’s how to reset the SMC:
- Shut down your MacBook.
- Press left Shift + Ctrl + Option + the power button at the same time and hold.
- Release all keys at the same time.
- Turn on the laptop.
SMC controls the computer fans, backlights, and indicator lights, as well as some aspects of the display, ports, and battery, so resetting it will force your MacBook to revert back to its default settings for all these things. If a transient issue in the SMC was causing the Service Battery warning, this should address it.
Other Ways to Address the Service Battery Warning on Mac
If your battery is still well within its theoretical cycle count and you have tried both calibrating it and resetting the SMC and the Service Battery warning still appears, you only have one option left: take it to an Apple Store. If it’s been less than a year since you bought your MacBook, you should still be under the warranty. However, after that point (unless you are under AppleCare and within the three-year extended warranty period) then a battery replacement will cost $129 or more.
How to Extend Battery Life
If you plan to keep your MacBook in service for a long time, then keeping your battery in top condition ought to be a priority. It’s the component that is the most likely to go out and need a replacement. Here are some suggestions for keeping your battery healthy.
Stay Plugged In
Obviously it’s great to be able to sit with the MacBook on your lap out on the patio and surf the web or write your novel while you enjoy the sunset; the whole point of a laptop is that it’s a portable machine. However, there are undoubtedly many times when you have it sitting on a desk like any other computer. When you have access to an AC outlet, use it. That reduces the number of times your MacBook will have to charge, and extends its life.
Avoid Temperature Extremes
MacBooks work in a wide range of outside temperatures, but 62° to 72° F is the ideal temperature range. Your machine will work just fine in cold temperatures; though your battery won’t last as long, it won’t be damaged by cold. However, CHARGING your battery in sub-freezing temperatures is very dangerous – never charge a lithium battery in the cold. Heat is another story; temperatures higher than 95° F can permanently damage the battery and reduce its capacity. Charging in high temperatures will cause additional damage. Your MacBook’s software should prevent charging in these extreme environmental conditions, but it never hurts to be aware.
Store at Half Charge
In storage, your MacBook battery will discharge, but very slowly. If you’re planning to keep your MacBook stored over a long period of time (more than a month), charge it to about 50% of capacity before doing so. Leaving it stored at full charge can cause it to lose capacity, while leaving it stored with no charge can cause it to lose the ability to charge at all. If you are storing the device for more than six months, then you should power it back up and recharge it to 50% again every six months. You should store your MacBook in a dry environment where it will not exceed 90° F.
Do you know of any other ways to keep your MacBook’s battery in good condition, or how to get rid of the Service Battery Warning? Have you had any particular issues with your MacBook or MacBook Pro battery? Tell us about it in the comments below.
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