It doesn’t matter how well you treat your MacBook, your battery won’t last forever. When battery health degrades, leaving your charger at home becomes increasingly untenable since the time between charges can reduce dramatically.

The Obvious Sign: Reduced Battery Life

It should go without saying, but a MacBook with greatly diminished battery life should benefit from a battery replacement. There are varying degrees of battery degradation, from “a few hours less than what I remember” to the machine lasting single-digit minutes when disconnected from power.

As your battery ages, it will lose capacity as part of the normal aging process. Modern MacBook batteries are good for 1000 cycles before needing to be replaced, while older models typically withstand 300 cycles. You can see how your battery is affected by usage using the graphs under System Settings > Battery.

Ideally, you want to see a steady decline rather than sharp dips in charge level (unless you know you’ve been doing something intensive like playing games or rendering video). Your Mac should remain relatively stable when not in use.

A “cycle” is one full charge from 0% to 100% and back to 0% again. Few people use their MacBooks in this way, but the cycles still add up. For example, two days of using half your battery life and charging from 50% to 100% would equal one cycle. You shouldn’t fear increasing your MacBook’s cycle count, since the battery is designed to be used.

RELATED: Debunking Battery Life Myths for Mobile Phones, Tablets, and Laptops

macOS Battery Service Warning

Your MacBook should tell you when it’s time to replace your battery. Click on the battery charge indicator in the menu bar in the top-right corner of the screen. If you see a “Condition: Replace Soon” or similar warning, macOS has determined your battery is deteriorating to a degree where it will soon need replacing.

If you don’t see any such warning, your MacBook battery should be working as normal and not in need of replacement.

You don’t have to replace your MacBook battery when this warning appears. Doing so will give your laptop a new lease of life when relying on battery power, but if you never leave your desk or find it convenient to carry a charger everywhere you go you can simply ignore it and carry on as normal.

High Cycle Count and Poor Battery Health

You can see information about your battery under System Settings > Battery. macOS should report the overall condition, with an “i” information button you can tap to see your maximum capacity percentage.

You can also find this information under System Information. Click on the Apple logo in the top-left corner of the screen then hold the Option key on your keyboard. Click on “System Information” and then navigate to the “Power” section in the sidebar. Battery information will be displayed at the top of the information panel, with “Cycle Count” available in the “Health Information” section.

Consult Apple’s battery health guide to work out what sort of cycle count you should expect from your MacBook before needing to replace the battery. To find out which MacBook you have, click on the Apple logo in the top-right corner of the screen and then choose “About This Mac”.

Unexpected Shutdowns or Overheating

Your MacBook will turn itself off sooner than you’d probably like if the battery needs replacing. Unexpected shutdowns or heat problems could also be explained by poor battery health. For example, if your Mac reports that it has a moderate amount of battery left and then shuts down before giving you the low battery warning, a faulty battery could be to blame.

The same is true of unexpected power loss while using your MacBook on battery power. This is an extreme example of a battery fault, where the cell can no longer deliver the required power to keep the machine from shutting down. Even if this is the case, the MacBook should run fine on mains power (at least it does on our old MacBook Air that has no battery inside it).

Older batteries may also be more prone to overheating. You can check your MacBook’s temperature using a free app called Hot (for both Intel and Apple Silicon models). The normal operating temperature for an Apple Silicon (M1 or later) CPU at idle is around 68ºF to 95ºF (20ºC to 35ºC), and around 120ºF (50ºc) or less for an Intel CPU. Under load, both machines can spike to around 212ºF (100ºC) on the CPU.

Take these temperatures with a pinch of salt, since the ambient temperature and usage conditions (for example, full sunlight) can make a big difference to how hot or cold your MacBook runs. You’re more likely to notice sluggish performance as a result of thermal throttling or spontaneous shutdowns if your Mac is affected by heat.

RELATED: 7 Tips to Keep Your Tech From Overheating

What to Do About Your Failing Battery

If your MacBook is still under warranty or covered by AppleCare+ or another insurance scheme, you may be eligible for a free battery replacement if your maximum capacity has dropped below 80%. You can check your eligibility under System Settings > General > About under the “Coverage” section. Make an appointment with Apple or an authorized service center using Apple Support.

Apple will test your battery and let you know if it needs replacing. If you’ve followed the instructions for checking your cycle count and battery health above, you’ll probably already know the outcome of this testing. If you have a 15-inch MacBook Pro manufactured between 2015 and 2017, you may be eligible for a battery replacement due to a recall.

It’s worth checking the Apple Service Programs website to see if your Mac is listed for a free battery replacement or affected by any other issues. If your MacBook isn’t covered by your original warranty or a service program, Apple can still replace the battery. This is the easiest way forward if you want your battery replaced, but it’s also the most costly.

You can check how much a battery replacement will cost using the Mac Repair & Service website. Expect to pay around $199 for a new battery, including parts and labor. In many cases, Apple will be able to fit a new battery on the same day, or you can use an authorized service center or mail-in service if visiting a retail location isn’t possible.

By going to Apple, you guarantee that only genuine Apple parts will be used. Alternatively, you can go to a third-party (unauthorized) service center nearby and have them replace the battery for you. This is likely to be cheaper but you may end up with third-party components (the quality of which can vary).

Finally, you can always replace the battery yourself at home. You can buy everything you need to do this (including the battery) on websites like iFixit or Other World Computing. Kits can cost from as little as $60 to around $100 and come with everything you need.

You’ll also find links to guides on iFixit’s website or YouTube demonstrating how to perform the replacement. Replacing a battery is considered a fairly advanced fix, so if you’re worried about things going wrong it might be worth getting someone else to do it. That said, if it’s an old MacBook you’re happy to risk and you’re keen to hone your repair skills, a battery replacement might make a perfect Sunday afternoon activity.

Keep Your MacBook Battery in Great Condition

There are a few basic practices you can employ to keep your MacBook battery in good condition. This includes making use of optimized charging, keeping the charge level between 40 and 80%, and avoiding extreme temperatures.

Do you have a 14 or 16-inch MacBook Pro from 2021, MacBook Air from 2022, or later? You can fast charge your MacBook with the right power adapter and cable.