The national standard for rechargeable batteries refers to the standard of technical specifications and safety requirements for rechargeable batteries formulated in a specific country or region. These standards usually include battery capacity, voltage, charging speed, cycle life, safety performance and other requirements.
The development of national standards aims to ensure the quality and safety of rechargeable batteries, protect the rights and interests of users, and promote the healthy development of the rechargeable battery industry. Different countries and regions may have different national standards for rechargeable batteries, such as GB\/T 18287-2013 standard in China and UL 2054 standard in the United States.
The standard charge is 1\/10 of the battery's capacity. The 550MAH is charged with 55MA of current. The voltage limit is 3V stop. Otherwise it will overcharge. It should be 2 nickel-metal hydride batteries in series 1.2V×2. The charging time can be known by monitoring the voltage with a voltmeter.