In response to the problem that large number of problems shown on the mobile devices such as overheating, aging and spontaneous combustion during 2015-2016, which caused by the fast charging function, this project aims to explore the reasons and design a new type of charging brick.

Research
By reviewing papers it‘s learned that fast charging causes problems for two main reasons:
- Rapid charging drives the occurrence of internal side reactions in the battery, the chemicals on the battery are destroyed, the reversibility of the battery decreases, and therefore the battery capacity continues to decrease.
- At the same time in the process of fast charging, the charging chip will generate a huge amount of heat, due to the limitations of the phone space, most of the heat in a short period of time is difficult to get effective evacuation in the small space of the phone, the accumulation of heat will not only affect the efficiency of the phone charging and the chemical properties of the lithium battery, while the heat dissipation will also accelerate the aging of other electronic components, thus causing danger.
However, the commercially available fast charging brick at that time could not provide the feature of free choice for users to switch to slow charging in leisure time when fast charging was not needed, thus reducing the danger.
Therefore, this project focuses on designing and building a circuit to control fast and slow charging and creating a prototype circuit board.
Board



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