Batteries don’t last forever. As you charge and discharge your battery, it degrades and over time, you get less battery life from a full charge. Eventually, the battery—or the device—needs to be replaced.

Battery Capacity Decreases Over Time

A battery doesn’t just go from good one day to bad the next. Instead, batteries slowly degrade over time. This capacity decrease is a gradual process—happening over many charge cycles—and you won’t necessarily notice until you realize you used to get a few more hours of battery power from a charge.

You can help prolong your battery’s life and keep its capacity up by properly caring for your battery. But you can’t avoid battery degradation forever. If you replace devices often—say a new phone every couple of years—you may never notice. Or, you may notice but the problem won’t get bad enough to do anything about before it’s time to replace your device again. But for devices like laptops, which you’re likely to keep for longer, you may have to replace your battery at some point.

Some devices will even warn you when it’s getting time to replace your battery. For other devices, you can often find third-party apps that let you check up on your battery’s health.

How to View a Device’s Battery Health

Unfortunately, many devices don’t display battery health warnings ahead of time. You’ll either notice a problem yourself or the battery will simply fail. Even devices that do include some kind of warning often don’t give you much advance notice. It pays to check up on battery health yourself once in a while.

Here’s how to find battery health information on some common operating systems and devices:

• Windows Laptops: We recommend NirSoft’s BatteryInfoView to find a Windows laptop’s battery health, but there are other utilities you can use instead.
• MacBooks: Hold down the Option key and click the battery icon on the menu bar. You’ll see a “Condition:” line displayed here.
• iPhones and iPads: You can actually ask Apple support to tell you your iPhone or iPad’s battery health
• Android Phones: Unfortunately, most Android users are out of luck. Some older phones would show battery health information if you opened the dialer and typed *#*#4636#*#*, but this doesn’t seem to work on modern phones.

For other devices, search for the type of device and “battery health” to get instructions.

When It’s Time to Replace a Battery

Whatever your device says about the health of its battery, the rest is up to you. If your battery reports it’s at 40 percent of its original capacity, but you’re still happy with how much battery life you get, there’s not much need to pay for a replacement until it declines to a point where it becomes bothersome.

How to Replace a Battery

If you have a smartphone, tablet, laptop, or another device with a removable battery, replacement is easy. You just need to purchase a replacement battery designed specifically for your device, power down your device, and then replace the current battery with the new one. This gives your device a fresh battery with maximum capacity.

However, devices these days are often made so that you can’t access the battery yourself—at least not easily or without voiding your warranty. Instead, you’ll need to have the manufacturer replace the battery for you. For example, you can take an old iPhone, iPad, or MacBook to an Apple Store and pay a fee to have Apple employees open your device and replace the battery for you. Check if your manufacturer offers this service.

Of course, even on devices without an easily accessible battery, if you’re so inclined and don’t mind the associated risks, you always have the option of doing it yourself. You could  open up your device, get a replacement battery, and try to seal it back up again. We don’t necessarily recommend this, though. Too many modern devices have batteries and other components that are glued together and not designed to be opened.

The battery health status your device reports can help you decide whether it’s time to replace your battery, but the decision is ultimately up to you. If your battery feels okay to you, then you don’t need to do a thing right now. Better to put that money toward a future device replacement. If the battery is no longer performing adequately and you’re not interested in replacing your device, then it’s time for a replacement.

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