What really tells you it’s time to replace a laptop battery?

When checking a laptop battery, which signal do you find most useful: full-charge capacity, cycle count, real-world runtime, or the capacity trend over time?

I’m launching Battery Health Lab to make Windows battery reports easier for non-technical users to understand. I’ve tried to present capacity health as useful context rather than a definitive hardware diagnosis, because runtime, temperature, calibration, and physical condition also matter.

I’d love to hear how other users decide when a laptop battery genuinely needs replacement. Your feedback may help improve the guidance shown with each result.