Why it matters for phone repair
Battery cycles are the primary driver of battery health decline. Every cycle causes permanent, irreversible capacity loss. Understanding cycle count helps evaluate how much life a second-hand phone has left.
How it works
Lithium-ion batteries degrade structurally with each cycle. Apple rates iPhone batteries to retain 80% capacity at 500 cycles. Singapore’s heat means real-world degradation often happens faster.
Shareable fact: Charging from 50% to 100% twice counts as only one cycle — a cycle is measured in total discharge equivalent, not charge sessions.
Real example
A second-hand iPhone 13 shows 81% battery health. A technician checks the cycle count: 680 cycles. At 500 cycles Apple rates 80% — at 680 this battery is well past its rated lifespan. The 81% reading is misleading. A replacement brings it to 100%.
Common mistakes
- Draining to 0% regularly. Deep discharges stress lithium-ion cells more. Keep charge between 20–80%.
- Ignoring cycle count when buying second-hand. Health percentage alone can be misleading without cycle count context.
- Thinking charging habits don’t matter. Fast charging and overnight charging at 100% increase degradation per cycle.
Related terms
- Battery Health — the cumulative result of charge cycles over time
- Charging Port — a damaged port affects how efficiently cycles complete
- Power IC — the chip that manages charge cycles and power distribution
Further reading
BreakFixNow replaces phone batteries in 30–45 minutes. 90-day warranty, no fix no fee.
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