In order to make the lunch box have better heat preservation effect, the box cover can also be designed as double-layer, and the middle is filled with heat preservation material as the heat preservation layer.
The power of the heating wire at the bottom of the box is generally 8-15 watts, and the battery adopts two 2-volt rechargeable batteries. The shape of the lunch box is similar to the usual lunch box, and the size is slightly larger. It can be made into different specifications and models.
The shell, bladder and cover of the lunch box can be made of common plastic products or metal products, such as aluminum, stainless steel, etc.
When using, charge the battery with 220 V commercial power through a separate charger at night, generally 6-8 hours. Before going out, put the hot rice, vegetables and soup into the corresponding space of the lunch box, cover the sealed cover on the vegetables and soup grid, and then cover the box. Turn on the heating switch, the battery will start to work and heat the lunch box slowly. Because there is a heat preservation layer outside the box and an electric heating wire for heating, the food can be kept in a certain temperature range. If it overheats, it will cut off the power supply automatically under the action of relay. When the temperature in the box is lower than a certain temperature, the relay will be automatically connected to continue heating and insulation. Generally, if you use a 10 watt heating wire and two 2-volt batteries, you can keep the temperature for 6-7 hours.
