How to check the battery health of a refurbished laptop

On Windows, run powercfg /batteryreport and divide the full charge capacity by the design capacity. The result is the battery health. Back Market sets 80% as its floor. If your battery is below the shop's floor, claim a repair or a replacement from the shop. If you would rather buy another laptop, a refurbished one here sells from €132 (16 GB), seen 16 September 2026.

What battery health means

A laptop battery holds less energy after many charge cycles. Microsoft explains why: "The capacity of lithium-ion cells is reduced after a certain number of times the battery is charged and then discharged."

Two numbers describe this loss. Microsoft defines them: "The full charge capacity shows the Watt-hours the battery can hold on a full charge now, while the design capacity shows the Watt-hours the battery could hold when it was new." Battery health is one number divided by the other. In Microsoft's words: "The maximum capacity of a battery is the ratio of its full charge capacity against its design capacity."

An example: a battery with a design capacity of 50 Wh and a full charge capacity of 40 Wh has 80% health. Its wear is 20%.

Some shops state a floor for battery health. Back Market sets its own: "Minimum 80% battery health with 100% charge capacity." If your shop states a floor, check your laptop against it on the day it arrives.

How to check it on Windows

Windows makes a battery report with one command. Microsoft's own steps are these:

1. Select Start and type Command prompt.
2. Right-click Command prompt, choose Run as administrator, and select Yes.
3. Type the command. Microsoft says: "At the command prompt, type powercfg /batteryreport, then press Enter."
4. Find the file. Microsoft says: "The battery report will be an HTML file that’s stored in a folder on your PC. The file location will be shown in the Command Prompt window."
5. Open that folder in File Explorer and double-click the report. It opens in your web browser.
6. Microsoft names Installed battery as a section to start with. Look there for the design capacity and the full charge capacity.
7. Divide the full charge capacity by the design capacity. That is the battery health.

How to check it on macOS

On a Mac laptop, open the Apple menu and choose System Settings. Click Battery and read the line for Battery Health. Apple shows one of two states. The weak one is: "Service Recommended: The battery's ability to hold charge is less than when it was new, or the battery isn't functioning normally."

Apple also counts charge cycles, and it sets a limit for each model. Apple says: "Your battery is designed to retain up to 80% of its original charge capacity at its maximum cycle count." To see the count, hold the Option key, open the Apple menu and choose System Information. Then select Power under Hardware.

How to check it on Linux

On Linux, the upower command reads the battery. The Arch Linux wiki names it: "Alternatively, you can use the upower abstraction utility:"

1. Run upower -e to list the power devices. Find the path that contains BAT.
2. Run upower -i with that path. It shows the details of that battery.

You can also read the kernel's own files in /sys/class/power_supply/BAT0/. On some laptops the folder has a different name than BAT0. Divide energy_full by energy_full_design. Some batteries report charge_full and charge_full_design instead. The kernel documentation describes the design values as "design charge values, when battery is considered full/empty."

Vendor tools

Some laptop makers have their own battery tool.

• Lenovo Vantage. Lenovo's support site has a page with the title "Check your PC Battery Health with Lenovo Vantage". Vantage is Lenovo's own app for its laptops.
• Dell Power Manager. Dell's user guide says: "Battery health indicates the amount of charge that is available to a system." The app shows the health as a heart icon and four circles. More filled circles mean a healthier battery. Dell shows this only for Dell batteries.

On any Windows laptop, the battery report above works as well, whatever the brand.

What to do with the number

Below the shop's floor: claim the guarantee. In the EU, a laptop from a shop has the legal guarantee: "Second-hand goods that you buy from a professional seller are also covered by the minimum 2-year guarantee." The rule covers goods that differ from the offer: "Under EU rules, if the goods you buy turn out to be faulty or do not look or work as advertised, the seller must repair or replace them at no cost." Contact the shop in writing and send the battery report. Our guide are refurbished laptops worth it explains your rights in full.

Above the floor but low: think about a new battery. On some laptops the swap is simple. The Lenovo ThinkPad T480 is the classic example. Notebookcheck reports: "The T480 preserves the dual-battery approach of its predecessors, which in this case constitutes a 24 Wh internal battery paired up with an external (hot-swappable) battery of the user’s choice." The external battery is a separate part, so you can replace it on its own. Our guide is the ThinkPad T480 still good covers the rest of that laptop.

Healthy: keep it. Check the number again once a year, so you see the wear before it surprises you.

If you would rather start again with a different laptop, the 16 GB table lists every refurbished offer from the cheapest up.

Questions people ask

How do I check the battery health of a refurbished laptop?

On Windows, run powercfg /batteryreport in Command Prompt and open the report. Divide the full charge capacity by the design capacity. On a Mac, open System Settings and click Battery. On Linux, run upower -i with your battery's path.

What battery health is good for a refurbished laptop?

80% or more is a good result. Back Market states 80% as its own floor. Apple designs its Mac batteries to keep up to 80% of their capacity at the maximum cycle count.

Where does powercfg save the battery report?

It saves an HTML file in a folder on your PC. The Command Prompt window shows the full path of the file after the command runs.

Can I return a refurbished laptop with a weak battery?

In the EU, a laptop from a shop has a legal guarantee of 2 years. Some countries let the shop agree a shorter period, but the EU sets a floor: "However, it must be no shorter than 1 year." If the battery is below the floor the shop stated, contact the shop in writing and send the battery report.