Glossary › Laptop Repair › Battery Cycle Count
What is Battery Cycle Count?
Battery cycle count is the number of full charges a laptop battery has been through. One cycle is 100% of the battery’s capacity used, whether in one go or spread over several days. It is the clearest single measure of how worn a battery is.
How a cycle is counted
Using half the battery today and half tomorrow adds up to one cycle, not two. Topping up from 80% to 100% every day uses a fifth of a cycle each time. So the count rises with how much you use the battery, not how often you plug in.
What the number means
Most laptop batteries are designed to keep a useful share of their capacity for a few hundred cycles, and some, including recent MacBooks, are rated for about 1,000. Past its rated count, a battery still works but holds noticeably less. Age and heat wear a battery too, so an old battery with a low count can still be tired.
How to check it
On Windows, open Command Prompt, type powercfg /batteryreport and open the report it saves. It shows the cycle count, and the full charge capacity next to the original design capacity. On a Mac, open System Information and look under Power.
When to replace the battery
Replace it when the full charge capacity has fallen to roughly two thirds of the design capacity, when the laptop shuts down with charge still showing, or at any sign of a swollen battery.
Related terms
Swollen BatteryDC JackUSB-C Power Delivery