How to Test Your Laptop Battery

If you suspect the issue with your device is coming from your battery, there are easy and handy ways to test the battery and confirm your suspicions.

Your PC turns on But the Autonomy Is Low

Before performing any diagnostics, when Windows detects a damaged battery, it will inform you directly of its condition and notify you that it needs to be changed.

However, if Windows does not give you an error message but you have lost autonomy, you can check the actual capacity of your battery by downloading HWInfo 64 which will give you the theoretical capacity of your battery as well as the current capacity.

After downloading and opening the ZIP file, you have to click on "HWiNFO64.exe". If a Windows prompt asks if you allow HWiNFO64.exe to run, click "Allow"
Then select "Sensors-only" check box and click on "RUN". Allow a few moments for HWiNFO load.

Once HWiNFO64 is open, it will show you all of the available information about your computer including information regarding your battery.

In our example, the initial capacity of the battery, when new, was 62Wh. HWiNFO indicates a capacity of 38.56Wh at 100% charge.

Our battery is therefore at ( 38.56 / 62 * 100 = ) 62.6% of its initial capacity. Since, the battery has lost (100 - 62.6 = ) 37.4% of its capacity, it will need to be charged more often.

Depending on the model of your laptop, HWiNFO will show you directly the result of this calculation and tell you the "Wear Level", in this example 37.4%, indicating that the battery lost 37.4% of its original capacity. Simply, if originally our battery gave us 3 hours of autonomy per full charge, it would now allow only 1hour and 52 minutes.

Your Laptop Does Not Turn On

If your laptop does not start after you have completely drained the battery, it may have caused a short circuit in the motherboard.
To verify that the problem is your battery, just remove the battery and try to start the laptop with just the power chord. If it restarts without a battery (plugged into the AC outlet), then the battery is out of order.