Split the two bags by how often items need to be accessed, not by category of item. The personal item — which stays with the traveler under the seat — should hold anything needed during screening or in-flight: the liquids bag, a laptop, headphones, travel documents, medication.
The carry-on, which usually goes in the overhead bin once boarded, can hold everything accessed less frequently: the bulk of clothing, a toiletry bag not needed until arrival, shoes.
This split also matters for weight distribution at check-in on airlines that weigh both items — if the cabin bag is close to its limit, shifting a genuinely non-essential item into the personal item (assuming it has room) can bring the cabin bag under the limit without leaving anything behind.
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