Carryvolt: Power Bank Check

Carryvolt is for the moment at the security tray, when someone asks how many watt-hours your power bank has and all you can see is "20000mAh" in tiny grey print. Photograph the label and Carryvolt reads it right there on your iPhone. Apple's on-device text recognition picks out the mAh, the cell voltage and the watt-hour figure if the maker printed one, and does the conversion when it didn't. You get the number staff actually check, in a size you can read. Your bag is a list of luggage tags: the power bank you always carry, the slim magnetic pack, the camera spares, the laptop. Each one shows its watt-hours and whether it is cleared, needs the airline's blessing, or cannot fly at all. Rule cards hold the limits. The built-in card follows the worldwide baseline that came into force in March 2026 — two power banks per passenger, nothing above 100 Wh without approval, nothing above 160 Wh at all, kept in the cabin and within reach, and no recharging a bank in flight. A second card covers the stricter carriers that allow only one. If your airline publishes something different, write your own card in a minute. Before a trip, tick the batteries that are coming and Carryvolt prints a battery pass: a verdict for each one, what to sort out before you leave, a packing checklist, and an optional reminder the evening before to charge everything and move it out of the hold bag. Share the list as plain text if someone else is packing. Range answers the other half of the question. Tell it what you need to keep alive and how long you are away from a socket, and it weighs that against the banks you are allowed to bring, including the energy lost on the way from cell to phone. If you are short, it tells you how big a bank would cover it — and whether that size would still be allowed. A few things Carryvolt is honest about. It cannot charge anything faster, test a battery or measure what is inside one; it reads what is printed and applies published limits. It is not an airline, an airport or a regulator, and carriers are free to be stricter than the baseline, so the rule cards carry the date they were summarised and links to the official pages. There is no account, no tracking and no server: your bag, trips and cards live on your iPhone only, and label photos are read and discarded, never stored or uploaded. For travel information only. Always confirm the current rules with your airline before you fly.