How to Know If Your Laptop Battery Is Shot

If your laptop’s battery life has dropped from a full workday to a frantic search for outlets, you’ve probably asked yourself: repair or replace?

The answer is usually straightforward, but before spending a dime, make sure the battery is actually the culprit.

Check the Battery First 
All laptop batteries lose their ability to hold a charge over time, so start by checking the battery's health first:

On a Windows PC, open Command Prompt, type powercfg /batteryreport and press Enter. A report will be saved to your user profile's main folder. Open it and compare the original "Design Capacity" to the current "Full Charge Capacity." If it has dropped below 80%, it's time to consider a replacement.

On a Mac, go to System Settings > Battery and click the "i" info icon next to Battery Health.

If the battery health is good, your charger may be the problem. Test with another known-good charger as a damaged cable, failing power adapter or damaged charging port can mimic a dead battery.

If you use your laptop strictly as a desktop and it stays plugged in at home, you might not even need a replacement.

Is the Laptop Worth Repairing? 
If the battery really is worn out, the question isn't what a new battery costs; it's really 'is the laptop itself is worth saving'.

If the screen and keyboard are in good shape, performance is snappy and you’re otherwise happy with it, replacing the battery is generally a cost-effective decision. That's especially true given today's higher laptop prices.

There’s also a hidden cost to buying a new laptop: the hassle of setting it up. Transferring files, reinstalling software, and reconfiguring email, printers, passwords, and personal settings takes a lot of effort and time.

However, putting significant money into an aging, budget laptop that's already sluggish or short on storage may not make financial sense.

Know Your Limits & Options 
Years ago, swapping a battery meant sliding a latch and popping a new one in. Today, most laptops use internal batteries requiring you to unscrew the case, navigate delicate cables or unstick heavy adhesives.

If you decide to replace it yourself, beware of cheap, unbranded knockoffs on online marketplaces. They can trigger system errors, degrade rapidly, or pose safety hazards. Stick to original manufacturer (OEM) parts or reputable suppliers. If opening the case sounds daunting, consult a professional to complete the job safely.

The Swollen Battery Warning 
There is one critical exception: a swollen battery. If the bottom of your laptop bulges, the trackpad lifts or the device won't sit flat, stop using it immediately. Do not squeeze or press on it. A swollen lithium-ion battery is a hazard and requires prompt replacement and proper disposal.

The Bottom Line 
A fresh battery is one of the few cost-effective repairs that can breathe years of new life into an otherwise solid laptop. Check its health first, weigh the age of the machine and skip the headache of setting up a new PC if your current one still meets your needs.