Measurements
Battery Health Check — Read Your Real Battery Status
Live read of your laptop or phone's battery from the browser. Charging state, level, and time estimates — no install.
Battery level
— %
State
—
Time to full
—
Time to empty
—
Updates live as your device's charge state changes. Wait 30–60 seconds for time estimates to settle after plugging in or unplugging.
This browser doesn't expose the Battery Status API. Safari and Firefox disabled it for privacy. Use the manual calculator below — or open this page in Chrome / Edge for live readings.
Manual: cycle count → expected health
Find your battery's cycle count in OS settings (macOS: System Settings → Battery → Battery Health → Info; Windows: powercfg /batteryreport in Command Prompt; iOS: Settings → Battery → Battery Health).
Estimated remaining capacity
100 %
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Frequently asked questions
Why doesn't this work in my browser?
The Battery Status API is supported in Chromium browsers (Chrome, Edge, Opera, Brave) and most Android browsers. Apple removed it from Safari for privacy reasons (battery state can fingerprint a device); Firefox also disabled it. On unsupported browsers we show a manual entry fallback so you can still calculate the most useful metrics.
How accurate is the time-to-full / time-to-empty?
Within a few minutes once charging or discharging has stabilised. The first reading after plugging in or unplugging is unreliable because the OS hasn't measured a steady draw rate yet — wait 30-60 seconds for the number to settle. Heavy load (gaming, video calls) can change the rate dramatically, in which case the estimate adjusts as conditions change.
What's a good battery health number for a laptop?
Modern laptops show 'maximum capacity' as a percentage of original. New: 100%. After a year of normal use: 92-96%. After 3 years: 80-88%. Below 80% is when most manufacturers consider replacement worthwhile — battery life will noticeably suffer. Apple displays this number directly in System Settings → Battery → Battery Health on macOS.
Why is my phone showing higher battery wear than my laptop?
Phones get charged 1-2x daily; laptops often weeks between full cycles. Cycle count is the strongest predictor of battery wear, and phones rack up cycles fast. Lithium batteries are also stressed more by being kept at 100% (which phones often are when on the bedside charger overnight) and by fast charging — both of which phones do more aggressively than laptops.
Can I improve battery health?
You can't reverse wear, but you can slow future wear: (1) keep charge between 20-80% when possible — full discharge and 100% charges are the most stressful states; (2) avoid heat (charging in direct sun or on a soft bed traps heat); (3) use slower chargers when not in a rush — fast charging generates more heat. Many modern devices have an 'optimised charging' mode that learns your routine and delays charging past 80% until you actually need it.
Should I replace a battery at 80% capacity?
It depends on usage. If your runtime feels short for what you do — your laptop dies after 4 hours instead of 8 — then yes, replacing makes sense. If your routine never demands long battery life (always near power), 80% is still fine. Apple Mac batteries are often replaceable for $100-200 at the Apple Store; PCs vary by model. Phones with sealed batteries are usually about $80-100 for an authorised replacement.
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