A well-built zip on a mid-range or premium case, used a reasonable number of times a year, commonly lasts five years or more before showing real wear — zip failure at this quality level is more often caused by trapped fabric or overloading the case past its capacity than by the zip mechanism simply wearing out from age.
Budget zips are typically lighter-duty, and can show wear — a slider that no longer grips the teeth firmly, or teeth that separate under moderate pressure — within one to three years of regular use, particularly on a case that’s frequently packed close to or past its intended capacity.
Overloading is a genuine accelerant regardless of zip quality: forcing a case shut against resistance puts far more stress on the zip track than normal closing, and is one of the more preventable causes of premature zip failure on any case.
Check with your airline and read the label before you follow anything here. Lithium battery watt-hour limits, liquids allowances and lock policies differ by carrier and by country, and change over time — the figures published by the airline or security authority you are actually traveling with take precedence over anything written on this site. A power bank or spare battery is carried exactly as its manufacturer and your airline specify, never estimated. We report what is published — a watt-hour rating, a size limit, a lock's official recognition — and this site describes the equipment only: nothing here is a guarantee about what a specific checkpoint will allow on a specific day.
Last reviewed 26 August 2026