Before considering this question, you need to be aware that rail transport regulations may vary from country to country or region. Be sure to check the relevant policies in advance before you travel!
In general, the small lithium batteries commonly found in portable electronic devices (such as mobile phones, tablets, laptops) can usually be carried on the train, and the national or regional railway authorities usually have no special restrictions on such batteries, but it is recommended to ensure that the battery is intact, unshorted, and carried with the device.
However, lithium batteries with a capacity beyond a certain range (such as batteries for energy storage or car batteries) are usually considered dangerous goods, and in most countries, such batteries need to go through the transport process of dangerous goods, which may not be carried by ordinary passengers, requiring the use of freight channels. However, it is difficult to generalize how much this standard is, and it needs to refer to local railway management regulations.
