Glossary
Battery cycles
One full discharge-charge cycle. Lithium-ion batteries degrade with each cycle; modern cells retain 80% of original capacity after 500–1,000 cycles in normal use.
A "cycle" is one full discharge equivalent — two half-discharges count as one cycle, not two. Manufacturers rate cells in cycles to 80% capacity (the industry standard end-of-life threshold).
Typical ratings
- Smartphones — 800–1,000 cycles. iPhone 15+ raised the target to 1,000.
- Laptops — 1,000 cycles.
- Wireless earbuds — 500 cycles (case battery shorter).
- EVs — 2,000+ cycles.
What shortens cycle life
- Heat. Charging hot or storing hot accelerates degradation.
- High state of charge. Long-term storage at 100% is hardest on the cell.
- Fast charging. Modest impact at modern thermal management; bigger impact on cheap chargers.
The longevity-friendly habit: charge to 80%, discharge to 20%, avoid heat. Most modern phones offer an "Optimized Charging" mode that approximates this.
Where this matters
Categories that use battery cycles
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