If you accidentally check a lithium battery (such as a loose spare or a high-capacity power bank) in your hold luggage, it will likely be detected and confiscated during the 2026 X-ray screening process. Modern airport scanners are now calibrated to instantly flag the rectangular cells of lithium-ion batteries due to the risk of "thermal runaway," which can cause fires in an inaccessible cargo hold. If the bag is still landside, security may page you to return to the desk to remove it. However, if you have already cleared security, staff will typically open the bag, remove the battery, and place a notice inside for you to find upon arrival; the device is almost never returned. In extreme cases where a battery slips through and catches fire, the aircraft's Halon suppression system would deploy, but the pilot would likely make an emergency diversion to the nearest airport. To avoid this, always keep your laptop, phone, and power banks in your carry-on luggage where they can be manually monitored.