The charging water bottle is filled with salt compounds. The liquid in the bag is not ordinary water, it contains conductive substances, and after the hot water bag is charged, the salt compounds will conduct electricity and heat up. Because of long-term immersion in salt compounds, the electrode may be corroded, rust, and rust into the salt compounds, the conductive liquid will turn yellow, will also reduce its resistance, the heating power of the hot water bag will increase, at this time, if the temperature controller of the electric hot water bag and non-self-resetting thermal circuit breaker fail, the heating temperature of the electrode may exceed 100 ° C. Causing the salt compounds to vaporize, which can lead to an explosion.