To check laptop battery health on Windows, run powercfg /batteryreport in Command Prompt and compare the battery’s design capacity with its full charge capacity; on a Mac, open System Settings > Battery > Battery Health. Anything above about 80% of the original capacity is healthy.
Windows: the quick way
- Press the Windows key, type cmd and open Command Prompt.
- Type
powercfg /batteryreportand press Enter. - Open the file it names (usually in your user folder, battery-report.html).
Under Installed batteries, note two numbers: – Design capacity: what the battery held when new – Full charge capacity: what it holds now
Divide the second by the first. Full walkthrough: the Windows battery report.
HP, Dell and Lenovo tools
Your laptop maker’s own app gives a simpler verdict:
| Brand | Where to look |
|---|---|
| HP | HP Support Assistant > Battery check, or press F2 at start-up for HP PC Hardware Diagnostics |
| Dell | SupportAssist or Dell Power Manager, or the battery info in the BIOS (F2 at start-up) |
| Lenovo | Lenovo Vantage > Device > Power > Battery |
These usually show a plain result such as “Good”, “Calibrate” or “Replace”.
Mac: battery condition and cycles
- Open System Settings > Battery.
- Click the (i) next to Battery Health.
You’ll see Normal or Service Recommended, and on newer Macs the maximum capacity as a percentage. For the cycle count, hold Option, click the Apple menu, choose System Information > Power. Details: MacBook battery cycle count.
Reading the numbers
| Capacity left | What it means |
|---|---|
| 90–100% | Like new |
| 80–90% | Healthy, normal wear |
| 60–80% | Worn: noticeably shorter runtime |
| Below 60% | Nearly done |
Most modern MacBooks are rated to keep 80% after 1,000 cycles. Many ex-UK laptops come in with batteries at 60–80%, so always check before buying: see our used laptop checklist.
When to replace
Replace the battery if: – Capacity is below about 60%, or it won’t last through a KPLC outage – The laptop dies suddenly at 20–30% – Windows shows “Consider replacing your battery” or the Mac says Service Recommended – The battery is swollen: the touchpad lifts, the case bulges or the laptop rocks on a table. Stop using it and get it replaced straight away; swollen batteries can catch fire.
Be careful with cheap replacements from street stalls. Fake batteries often claim high capacity but hold far less and may lack safety circuits. Ask a trusted fundi for a genuine or reputable-brand battery and a written warranty.
Until then, a few habits help: make your laptop battery last longer.
Quick answers
On Windows, run powercfg /batteryreport and compare full charge capacity with design capacity. On a Mac, go to System Settings > Battery > Battery Health.
80% or more of the original capacity is good. Below about 60%, plan to replace it.
Open HP Support Assistant and run Battery check, or use HP PC Hardware Diagnostics (F2 at start-up).
