Battery cycle count
A counter that increments each time a laptop battery completes a full discharge-recharge equivalent; used as a proxy for battery health and remaining lifespan.
A battery cycle is one full discharge and recharge of a laptop battery, whether all at once or accumulated over multiple smaller drains. macOS tracks the cycle count for every Apple Silicon and Intel MacBook. Apple rates current MacBook batteries to retain 80% of original capacity for up to 1,000 cycles, after which performance and runtime degrade noticeably.
Cycle count is the single best signal of remaining battery life on a MacBook. A 2-year-old MacBook with 50 cycles has barely been used; the same machine with 800 cycles is approaching replacement territory. Listings often advertise 'great battery' without disclosing the count, which buyers should always ask for.
You can check cycle count in macOS via System Settings or system_profiler SPPowerDataType. A Mac in front of you takes one minute to check. A Mac in a listing requires the seller to send a screenshot, which can be edited, or a Macfax report, which can't.
Macfax Premium reports include the current cycle count, the design capacity, and the present capacity, plus a freshness timestamp. Basic reports skip the hardware-health checks; cycle count is a Premium-only field.
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