Foreign residents traveling within or from Japan will face new restrictions on mobile batteries starting April 24th, as the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) implements safety measures following multiple incidents of batteries catching fire or emitting smoke on aircraft. According to NHK, the new regulations prohibit passengers from using mobile batteries during flights and limit carry-on allowances to two units per person. The restrictions apply to all domestic and international flights departing from Japanese airports, affecting business travelers, tourists, and residents alike who regularly rely on portable chargers for their devices. The decision comes after a concerning increase in incidents involving mobile batteries aboard aircraft. While the exact number of incidents has not been disclosed, the ministry deemed the frequency serious enough to warrant immediate regulatory action. Lithium-ion batteries, commonly used in mobile battery packs, pose fire risks when damaged, improperly manufactured, or exposed to extreme conditions—hazards that are particularly dangerous in the confined environment of an aircraft cabin. Under the new rules, passengers may still bring mobile batteries in their carry-on luggage but are strictly prohibited from using them during flight. This means travelers cannot charge their smartphones, tablets, or other devices using portable battery packs while in the air. The two-unit limit per passenger represents a significant restriction for those accustomed to carrying multiple chargers for extended trips or business purposes. It's important to note that mobile batteries have long been prohibited in checked luggage on Japanese flights due to fire safety concerns. The new regulations tighten existing rules by addressing in-flight usage, which authorities now consider a preventable risk factor. Passengers who violate these rules may face penalties, though specific enforcement measures have not yet been detailed by the ministry. For expats and foreign travelers, these changes require careful preparation before flying. Business travelers who frequently work during flights will need to ensure their devices are fully charged before boarding or rely on aircraft power outlets where available. Many modern aircraft operated by Japanese carriers like ANA and Japan Airlines offer USB ports or power outlets at seats, particularly in premium cabins and on newer aircraft models, though availability varies by aircraft type and route. The two-battery limit may pose challenges for travelers on long-haul international flights or those carrying multiple devices for work. Photography enthusiasts, remote workers, and digital nomads who typically travel with several battery packs will need to prioritize which units to bring and consider alternative charging solutions at their destinations. Passengers should also be aware that these regulations apply specifically to standalone mobile battery packs. Devices with built-in batteries, such as smartphones, laptops, and tablets, remain usable during flight in accordance with existing airline policies regarding electronic device usage. However, the batteries within these devices must meet standard safety requirements and capacity limits already in place for air travel. The ministry has not announced whether these measures are temporary or permanent, suggesting they will remain in effect for the foreseeable future. Airlines operating in Japan are expected to update their safety briefings and informational materials to reflect the new rules, and airport security may conduct additional checks to ensure compliance. For foreign residents planning domestic or international travel from Japan, the key is preparation. Charge all devices fully before departure, pack only essential mobile batteries within the two-unit limit, and familiarize yourself with your airline's in-seat power availability. While these restrictions may cause inconvenience, they reflect Japan's characteristically cautious approach to public safety—an approach that has contributed to the country's excellent aviation safety record. Travelers with questions about specific battery models or capacity limits should contact their airline directly before their flight date to ensure compliance with both the new Japanese regulations and international aviation safety standards.