Background Effective January 1, 2009, the latest version of the Technical Instructions for the Safe Transport of Dangerous Goods by Air issued by the International Civil Aviation Organization (ICAO) added UN serial numbers for dangerous goods, and lithium batteries will be classified as lithium-ion batteries (UN 3090 and UN 3091) and lithium metal batteries (UN 3480 and UN 3481). The regulation states that lithium batteries cannot be transported by air if they do not come with a test report or certificate of approval based on UN38.3.

The demand for energy in countries around the world continues to increase, but due to the unstable nature of renewable energy, solar photovoltaics, wind turbines, and energy storage equipment must be widely installed. This has become an emerging high-tech industry and has been listed by the government as one of the six core strategic industries. In November 2022, the world's largest single-phase energy storage power station supplied by BYD Energy Storage was successfully put into commercial operation on the west coast of the United States, which became hot news in the industry. The independent energy storage power station is provided by BYD Energy Storage, a 1500V grid-level energy storage product BYD Cube T28, with an energy storage capacity of nearly 1.7GWh. Large-scale enterprises continue to join the energy storage track, and technology is advancing by leaps and bounds. How to develop energy storage systems to higher voltage levels, larger system scales, and higher safety and stability has become the focus of competition among various companies.

Hydrogen energy, as an important way of efficient and clean production and utilization of electric energy, is steadily advancing in my country, and its application scenarios continue to expand. In the "Action Plan for Carbon Peaking Before 2030" issued by the State Council, 11 items involve the field of hydrogen energy, which points out the way in many aspects such as transportation application, technological research and development and innovation. In 2021, hydrogen energy will grow rapidly in the field of commercial vehicles, especially heavy trucks, and more than 1,000 hydrogen energy vehicles will be demonstrated in the Beijing Winter Olympics, basically all of which are passenger vehicles, covering buses and group shuttles.

Zero-volt load means that the electronic load can output a rated full current at a very low input voltage, and the current can be as high as hundreds of amperes. The electronic load has an unavoidable minimum internal resistance due to the conduction-drain-source internal resistance of the field effect transistor, and requires a certain minimum DC input voltage (UMIN) to enable the load to absorb the full rated current. Below this minimum operating voltage, the load current will decrease linearly. Usually below 3V, the load transistor is in the saturated working range, the current control ability becomes weaker, and the dynamic response becomes worse. The power supply voltage must be greater than the minimum operating voltage of the load, and the voltage drop of wires, relays, connectors, etc. under high current needs to be considered.

From January 1, 2009, the latest effective version of the "Technical Instructions for the Safe Air Transport of Dangerous Goods" issued by the International Civil Aviation Organization (ICAO) has added the UN (United Nations) serial number of dangerous goods, and lithium batteries will be classified as Enter lithium ion batteries (UN 3090 and UN3091) and lithium metal batteries (UN3480 and UN3481). According to this regulation, if lithium batteries do not have a test report or relevant approval certificate based on UN38.3, they cannot be transported by air. The Civil Aviation Administration of China (CAAC) has issued the "Lithium Battery Air Transport Specifications" to airlines and dangerous goods-related transport units to strengthen the transport safety of lithium batteries.