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No laptop battery lasts forever. While there are ways to optimize its lifespan, such as ditching harmful habits that may be killing your laptop battery, it's likely you'll eventually need to replace this essential component. However, the signs of a failing battery aren't always as obvious as your device sending you an alert letting you know it's time for a replacement. That's why it's helpful to familiarize yourself with some of the less obvious signs that a laptop battery might be dying.

Several of the red flags here could potentially indicate a range of technical issues. It's true, of course, that a failing battery isn't always to blame for these types of laptop problems. That said, battery trouble is often the culprit in these instances. While you should take steps to confirm the root of any of these problems, which may involve bringing your device to a professional, these are often signs that a laptop's battery is on its last legs.

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Has your device begun shutting down with no apparent warning when it's running on battery power? There are several potential causes of this issue. If it occurs when your battery nevertheless indicates it has sufficient charge to keep the laptop running, you might understandably assume that another factor is to blame. It's certainly not a bad idea to run a virus scan and confirm that a piece of malware isn't the issue.

If your scan indicates no viruses or malware, a laptop crashing without warning could be a sign of a failing battery. This may be the case even if the battery supposedly still has a charge. A functioning laptop battery should provide the device with a consistent flow of power. The laptop may shut down unexpectedly if the battery fails to do so effectively. A battery that doesn't supply consistent power is likely faulty, damaged, or dying, and it will probably need to be replaced.

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The amount of time it takes for your laptop to charge usually shouldn't vary all that much. If it takes your laptop longer to charge than normal, this might be a sign of a dying battery. Be aware that taking a long time to bring it back to full isn't the only charging issue that could be linked to battery trouble.

For example, you might notice that charging is inconsistent. Sometimes, the laptop charges reliably, while in other instances it may not. Even if the device charges up, its battery power may nevertheless drain more quickly than expected. A battery that doesn't retain its charge for as long as it used to is probably in need of a replacement.

A similar problem that can be easy to overlook if you're not actively paying attention to it is fast, seemingly random, or unexpected changes in a battery's charge. For example, maybe your battery is at 80%, then within a few minutes, it depletes to 50%, only to shoot back up suddenly after. This is yet another red flag that you should install a new battery. It's worth noting that, although it's technically possible to run a laptop without a battery by relying solely on AC power, doing so isn't recommended. For instance, a sudden cut to the power could result in the device crashing, resulting in any unsaved work being lost.

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You'll find various estimates for how long a laptop battery is supposed to last before it needs to be replaced. Some will claim a laptop battery is typically only reliable for 2 to 3 years, while others will suggest 2 to 5 years is more of a reasonable lifespan. In reality, a laptop battery can essentially be charged only a finite number of times. What this number is varies from one laptop battery model to another, but it's typically somewhere between 300 and 1000.

In any case, a laptop battery that's over 2 years of age definitely isn't getting any healthier. This doesn't necessarily mean you need to replace the battery as soon as it hits its second birthday. However, it does mean that you should start monitoring for the warning signs listed here. Be prepared to replace the battery if you notice any other issues developing.

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Most of the issues here should prompt you to start looking into replacement batteries sooner rather than later. However, this particular sign of a failing battery tells you it's time to avoid using your laptop entirely until a professional has addressed the problem. You could risk injury if you continue using your device when the battery is damaged in this capacity.

Do you notice the battery seems to be swelling? Similarly, you might notice that its housing is cracked, or the laptop looks swollen around the trackpad or keyboard areas. This could be the result of chemical processes causing the battery to release gases internally. If you continue using the device with a battery in this condition, it could theoretically catch fire or even explode. See a professional repair tech right away to fix the issue.

Keep in mind that there are certain steps you can take to prevent your battery from dying prematurely. For example, you should try not to let your battery's charge dip below 20% before hooking the laptop back up to AC power. Just remember that any laptop battery will die eventually. Monitoring for these warning signs can help you anticipate when this may be happening, giving you the chance to replace the unit before the battery fails for good.