Wireless charging technology in portable energy storage devices

Wireless charging technology in portable energy storage devices

The wireless charging function in portable energy storage power supplies is usually achieved by integrating a wireless charging transmitter, which follows specific wireless charging standards, such as Qi standard, and transmits energy through the generation and reception of electromagnetic fields. This technology allows compatible devices to charge without a physical connection, simply placing the device in the wireless charging area of the energy storage power supply.
There are currently two commonly used wireless charging technologies, one is electromagnetic induction wireless charging, which is also the most common wireless charging method, using Faraday's electromagnetic induction principle. In portable energy storage devices, there is a transmitting coil (usually integrated inside the energy storage device) that generates a changing magnetic field when current passes through this coil.
There is also a receiving coil on the back of the receiving device. When the receiving coil approaches the transmitting coil, the changing magnetic field will induce the generation of electromotive force in the receiving coil, thereby generating current and charging the device's battery.
As for magnetic resonance technology, it is more advanced, allowing charging to occur over larger distances and more flexible positional relationships. This technology is also based on electromagnetic induction, but incorporates the concept of resonance. In the system, both the transmitter and receiver are tuned to the same resonance frequency. When the transmitting coil oscillates at a specific frequency, it not only directly induces current in adjacent coils, but also can transfer energy to distant receiving coils tuned to the same frequency through resonance in the magnetic field in the air.
This method can achieve wireless charging over long distances while reducing the requirement for precise alignment of charging positions, making it suitable for portable energy storage devices to provide a more flexible charging experience for multiple devices in the surrounding environment.
Of course, in terms of technology, wireless charging in portable energy storage devices also needs to adapt to larger power outputs to meet the charging needs of different devices, maintain efficient and stable charging performance in outdoor environments, and support multiple devices and charging protocols to ensure wide compatibility.

Selection of wireless charging chips

Generally speaking, to achieve wireless charging, there needs to be a transmitter, which is a charger. The transmitter generates an alternating magnetic field through AC or DC electricity, which can oscillate at a certain frequency in space. After the receiver, which is a portable energy storage device, approaches, the alternating magnetic field generated by the transmitter generates current in the coil of the receiver through electromagnetic induction.
And this process requires the assistance of wireless charging chips. For wireless charging chips applied in energy storage devices, they need to have functions such as energy conversion, protocol support, power output, efficiency optimization, and also need to have characteristics such as integration, safety, intelligence, compatibility, and multifunctional integration.
At present, there are also many wireless charging chips in the market that can be applied in portable energy storage devices, such as TI's BQ25123, which supports an output power of 3W and is suitable for wireless charging applications that comply with Rezence standards. It integrates digital control and communication functions to achieve efficient power management.
The BQ25970, also from TI, has a higher power output and can support up to 6.74W, making it suitable for devices compatible with Rezence and PMA (Power Matters Alliance) standards.
The CY8C95000 chip provided by Cypress supports up to 5W of wireless charging power, suitable for devices that meet Qi standards. It has optimized power management and rich integration features, making it equally suitable for portable energy storage products. In addition, NXP's T5795 supports 5W output power and is suitable for wireless charging solutions that comply with Qi standards.
If you want a higher power, there is also STWBC-WA developed by ST, which supports up to 15W output power and is suitable for various standards, including Qi standards. AOS's AOC5917 can also support an output power of 15W.
Many domestic enterprises have also launched corresponding solutions, such as Jinxin Micro, Yingjixin, Yichong Wireless, VIP Innovation, Dixin Gravity, Zhirong Technology, Nanxin, etc.
These domestic wireless charging chips have different power levels and functions, which can meet the diverse needs of energy storage devices. With the advancement of technology and the growth of market demand, it is expected that more innovative wireless charging solutions will be developed.
It should be noted that currently, the applicability of wireless charging technology in portable energy storage devices needs to be comprehensively considered based on specific application needs, cost budgets, technical specifications, and market trends. With the advancement of technology and standardization, wireless charging may become a more practical and widely accepted feature of energy storage devices in the future.

Summary

Currently, wireless charging chips typically possess efficient power management capabilities, good thermal management characteristics, and compatibility with various international standards. When choosing a wireless charging chip, factors to consider include output power, efficiency, size, cost, and whether it meets specific market standards. With the continuous development of the portable energy storage market, these chips are also constantly evolving to meet more efficient and convenient user needs.