Display cart and its power supply system and power supply method

A power supply apparatus for a display cart comprising:

• a battery configured to supply power to an electric apparatus mounted at the display cart;
• an external power supply configured to supply power to at least one of the battery or the electric apparatus;
• and
• a capacity management system including a control device, a power delivery device, and a capacity statistic device, wherein:
• the control device is configured to determine output power of the electric apparatus;
• the capacity statistic device is configured to determine a remaining capacity in the battery, calculate a remaining power supply duration according to the output power of the electric apparatus, and send a statistic result indicating the remaining capacity and the remaining power supply duration to the control device;
• the control device is further configured to control the power delivery device to supply power to the electric apparatus according to the statistic result;
• and
• the power delivery device is configured to start or stop supplying power to the electric apparatus under control of the control device.

A power supply method for a display cart comprising:

• supplying power to an electric apparatus using a power supply apparatus of the display cart by a battery and/or an external power supply;
• supplying power to the battery by the external power supply;
• and
• detecting and managing, by a capacity management system, capacity in the battery, including:
• determining, by a control device of the capacity management system, output power of the electric apparatus;
• determining, by a capacity statistic device of the capacity management system based on the output power of the electric apparatus, a statistic result including a remaining power supply duration and a remaining capacity in the battery;
• and
• controlling, by the control device, a power delivery device of the capacity management system to start or stop supplying power to the electric apparatus according to the statistic result.