The New Track of Fast Charging and Wireless Charging, With Countless Possibilities to Be Presented

The Contradiction Between Battery Capacity and Mobile Phone Power Consumption

The energy density of lithium batteries in the mobile phones has reached its physical limit in the technical bottleneck period. The mobile phone battery started from the Ni-Cr battery equipped with Motorola's first mobile phone in 1973, which is the first appearance of the mobile phone and has a milestone significance. The battery of that mobile phone was half the size of the mobile phone, and the endurance capacity was only half an hour, but the charging time was as long as ten hours. Ten years later, mobile phone Ni-Cr batteries were replaced by NiMH batteries, completing the first update. Until the early 1990s, lithium batteries were officially put into commercial use, which have been developed for forty years. Human beings have devoted all their efforts to the development of lithium battery technology. The battery capacity of mobile phones has been greatly improved from the initial stage, but due to the physical characteristics of lithium batteries and the size of the phone, heat dissipation performance, and cos, the overall growth rate of mobile phone capacity is relatively slow at this stage.

The power consumption of mobile phones continues to increase. Nowadays, to meet the needs of different consumers, the functions of smartphones are increasing, and the scale and speed of power consumption of mobile phones are constantly improving, which puts forward higher requirements for the battery life of mobile phones. Among them, the main components of mobile phone power consumption are the CPU/GPU, screen, mobile data, and sensor/BT/GPS.

As the main tool for content output and human-computer interaction, the smartphone screen occupies the largest part of the power consumption of the whole machine. The main power consumption parts are the backlight and touch sensor, in which power consumption is increasing year by year with the increase of screen pixels and screen brightness. The high energy consumption brought by the high resolution of the screen is mainly due to the increase in the calculation of the pixels that are doubled by the GPU.

The Above Contradictions Give Birth to Fast Charging Solutions

Fast charger speeds up the charging of the mobile phone, which shortens the charging time of the mobile phone by adjusting the voltage and current value when the mobile phone is charging. Traditional fast charger solutions include high voltage with low current and low voltage with high current.

The high voltage with low current achieves the conversion from high voltage with low current to battery terminal low voltage with high current by two steps of the charging head and the battery terminal, in which the related hardware does not need to be customized, and the cost is low, but its voltage reduction efficiency is not high, with large power consumption; low voltage with high current is one that the battery section can withstand directly after the first step-down of the charging, and its charging efficiency is high, only heating at the charging head, but showing the characteristics of high cost and poor compatibility.

Fast Charging Market Capacity Continues to Expand

Wired chargers, as a standard accessory, are bundled with smart terminal equipment whose market continues to grow around the world, which means that more than one wired charger for every smart terminal equipment sold is sold at the same time. Due to factors such as loss, the ratio of shipments of wired chargers to smart terminal equipment is greater than 1 to 1. Fast charger is one of the main solutions for mobile phone power consumption and endurance capacity, in which the market scale continues to grow. The scale market of the fast charger in 2017 was 246 million US dollars, accounting for 20.20%, and it is expected to reach 391 million US dollars in 2022.

Power, Portability, And Safety Are the Three Major Pursuits of Fast Charging Technology in the Future

Under the trend of fast charging, mobile phone brands and third-party charging brands have launched fast chargers with higher power, safer, and more portable.

In June last year, Anker launched the "PowerPort Atom PD2 GaN charger", which is a high voltage with high current, using GaN switches; in September of the same year, Huawei launched the "20W SCP fast charge charger", also the high voltage with high current, which uses charge to lower voltage and monitor smartly.

In July of this year, OPPO launched the "SuperVOOC Flash Charger" with a power of 125 watts, which uses 6C series double cells, parallel three electricity, and pumps to achieve greater power technology, and uses 14 temperature sensors and 5 levels of safety. Safer effects are achieved by protection mechanisms. In the same month, Xiaomi launched a high-voltage and high-current "120W second charging charger", and VIVO also launched a high-voltage and high-current "Super Flashcharge" with a power of 120W.

It can be seen that fast charging technology is not limited to the two traditional solutions. The high-voltage with high-current solution will become the mainstream solution for fast charging in the future; GaN switches can be suitable for high-frequency, high-power working environments, which are smaller, faster, and more efficient and expected to be an important component of the charging scheme.

Wireless Charging Is Another Solution to the Above Contradiction

Wireless Charging Technology is one that uses electromagnetic induction or other AC induction principles for power transmission. There are four main technologies that can realize wireless charging, including electromagnetic induction, magnetic resonance, microwave, and electric field coupling, among which, electromagnetic induction technology has become the most widely used technology due to the advantages of low difficulty, early start, and mature industry development. In 2017, it already accounted for 85% of the entire wireless charging market and nearly 100% in the low-power charging market such as mobile phones.

The two technologies of fast charging and wireless charging show their unique advantages in different aspects and have become an important means to solve the battery life of mobile phones. Some manufacturers have launched wireless fast charging at this stage, the overall market is not large. If the two solutions can be perfectly combined, it will be a breakthrough in charging methods. We believe that wireless fast charging will gradually become popular in the future. It may not be impossible for devices to achieve autonomous adjustment of the charging mode in appropriate scenarios.