Learn When to Replace your Windows Laptop Battery

If you have tried all the tricks to reduce battery usage like dimming your screen, closing apps and turning off unused antennae, but your laptop's battery still can not hold a charge or dies after few minutes, it might be time to replace the battery.

A battery's capacity (the amount of energy it can hold) depletes over time. Eventually, your once high-endurance laptop might only last a couple hours or minutes. Same goes for phones and tablets.

On Windows, the best way to find out if it's time to replace your battery is to generate a battery report.

This command also shows you some detailed information about your laptop's battery, including its design capacity and the last full charge. With this data you can calculate how much (percentage-wise) your battery has deteriorated over time.

How to generate a battery report in Windows

For Windows 7

1. Click Start button and type cmd in Search programs and files box
2. Right click on cmd.exe listed at the top of the Start menu and click Run as administrator
3. Next type powercfg -energy in the command prompt and press Enter
   
   powercfg will enable a trace for 60 seconds. If you want to use it for more information than just the battery details, make sure no other processes are running during that time

After 60seconds, powercfg will generate a report (in html format) which shows errors, warnings etc. Since we directed the command prompt to your desktop, the report will be placed on your desktop as energy-report.html. 

Just open the report in your web browser & scroll down to the Battery Information section. There's a lot to learn from the battery report, like your battery's capacity history (how it's depleted over time) and analysis for the last three charge cycles. But for our purposes, the most important metric is 

Design Capacity versus Full Charge Capacity

Design Capacity is how much power your laptop could hold when you unboxed it. Full Charge Capacity is how much it can hold now. For instance, my laptop's Design Capacity is 62,160 mWh while the Full Charge Capacity is now 32,880 mWh. 

For me, the depletion is almost half and still tolerable. So it means my battery only last half the original installed power. But if your Full Charge Capacity is drastically lower than the Design Capacity, you might want to find out if it's possible to replace the battery. 

For Windows 8 & 10

Microsoft added a hidden “Battery Report” feature to Windows in Windows 8 and 10.

This feature is built into the PowerCfg command. You can also use PowerCfg to generate an “Energy Report,” which will give you recommendations for ways you can reduce your computer’s energy usage and extend its battery life.

1. Search for command prompt in Search programs and files box
2. Right click on command prompt or cmd.exe listed at the top of the Start menu and click Run as administrator 
3. Next type powercfg /batteryreport in the command prompt and press Enter

The command will save a battery report to your user account’s directory. That’s at C:\Users\NAME\battery report.html. Head to your user directory in a File Explorer window and double-click the file to open it.