How to check your iPhone's battery health and cycle count

“Apple equips iPhones with built‑in diagnostics that let U.S. users see both the Maximum Capacity percentage and the exact charge‑cycle count, helping them gauge whether a device is still viable for resale or daily use. The Battery Health screen (or Battery Health & Charging on older models) shows a capacity estimate, warns when it falls below the 80 % threshold, and offers Optimized Battery Charging and a maximum‑charge limit on iPhone 15‑series devices to extend longevity. Knowing the cycle count—1,000 cycles for iPhone 15 and later, 500 for earlier models—lets consumers decide if a replacement battery is warranted before performance throttling kicks in. Expert Analysis: Monitoring battery health is increasingly critical as the U.S. market shifts toward longer device lifespans and stricter consumer‑rights expectations; informed buyers can negotiate better prices on used iPhones, while Apple may see reduced warranty claims if users proactively manage battery wear.”