With the increase of users' demand for mobile phone life time, mobile phone fast charging technology came into being. The rapid development of fast charging technology provides a guarantee for the diversified and practical promotion of large screen mobile phones. Since 2018, more and more smart phones have broken through the 20W mark in fast charging power and launched an impact towards higher power. What has such a complex fast charging technology improved?
The core of smart phone battery is still lithium ion. The general battery capacity is around 3000mAh. It takes 3 ~ 4 hours for an ordinary 5V / 1A charger to fill the battery. The fast charging technology can compress the time to about 1 hour, which greatly improves the efficiency. From a physical point of view, the charging power is equal to the product of voltage and current. When the battery power is certain, the power indicates the speed of charging. At present, there are three ways to shorten the charging time:
1. Constant current and increased voltage: when the current of ordinary charger is maintained at 1a, reduce the 220V voltage to 5V charger voltage, and then reduce the 5V charger voltage to 4.2V battery voltage. When the voltage is increased to 9V, the charging time can be reduced to 50% theoretically, but the disadvantage is that it will cause the charger and mobile phone to heat up and damage the battery.
2. Constant voltage and increasing current: under the condition of constant low voltage, this technology increases the total value of current by adding multiple parallel circuits. After the circuit is shunted in parallel, the sub power borne by each part of the module is not large, which can well control the heat dissipation of the circuit and avoid the hot of the mobile phone.
3. Increase of voltage and current: Although this way of increasing current and voltage at the same time can bring considerable improvement of charging speed, the heat loss and shortening the service life of the circuit are also big problems, and the technology needs to be further developed.
In a word, the selection of fast charging scheme is a comprehensive technical scheme, and the above three schemes have their own advantages and disadvantages. Ordinary consumers' pursuit of fast charging technology will provide a steady stream of R & D power to the market. In the future, engineers need to make breakthroughs in the research of new technologies, make the fast charging technology safer and more reliable, and bring a better experience to mobile phone users.
Post time: Mar-28-2022