OPPO: Faster Charging Doesn't Affect Battery Lifespan, Charging Cycles Do

Battery life is a major component of any smartphone nowadays; if your phone's battery can't last a whole day, you might be left without any means of communication when it dies. As important as a large battery is, being able to get the battery fully charged in the shortest amount of time is equally as important. That 15 minutes you have to charge the phone before you head out might be the difference between your phone going flat in the middle of the day or lasting till you get home. That's where OPPO’s VOOC Flash Charge technology innovation comes in.

Jeff Zhang, Chief Scientist of OPPO VOOC Flash Charge

We spoke to Jeff Zhang, Chief Scientist of OPPO VOOC Flash Charge Technology, to get a better understanding of fast charging and what the technology might hold for us moving forward.

What are the other considerations to achieve fast charging?

redit: OPPO

The motivation of OPPO’s innovation on VOOC Flash Charge technology is to create the best all-round charging experience for our users. To create this best all-round experience, factors such as efficiency, overheating, safety, portability and compatibility all need to be considered, from which, other aspects such as potential use cases, design and form factors are assessed in depth.

Is there a limit to how fast we can charge?

OPPO is constantly pushing boundaries on how fast we can charge through research and innovation. In July 2020, OPPO introduced the 125W SuperVOOC, once again setting new records for charging speed with its ability to charge a 4000mAh battery to 41% in five minutes and fully charge it in just 20 minutes. OPPO also launched the 65W AirVOOC wireless Flash Charge technology in July 2020, which enables a 4000mAh battery to be charged to 25% in five minutes, with a full charge in just 30 minutes.

Building on to your question on how fast we can go – the more pertinent question of today is how far can we go. Following this vision, OPPO launched a new project this year – The Flash Initiative – that bring our proprietary VOOC technology to automobiles, public spaces, and chips inside a wide variety of technologies, to allow people to charge any device, anytime, anywhere and everywhere.

How does OPPO achieve safe fast charging without generating too much heat?

Safety is one of the most important considerations for OPPO when developing our VOOC Flash Charge technology. VOOC’s direct charging architecture enables the power to be directly transmitted to the battery without any voltage conversion, which reduces the amount of heat generated by voltage conversion and improves charging efficiency. OPPO has also introduced a five-fold safety protection system to enhance safety in VOOC Flash Charge technology and has been exploring how new materials, AI algorithms, charging architectures and other factors can be used to ensure safe fast charging.

Credit: OPPO

The fuse with lower impedance contained in the Flash Charge has a five-fold safety protection system that is able to immediately blow if there is an electric current overload or other abnormality. This protects the battery by physically isolating it from the electricity supply. The upgraded fuse design has lower internal resistance and improved performance, helping to further improve the safety of the charging system.

OPPO’s proprietary Battery Safety Detection Chip with embedded AI algorithms is also able to detect and act accordingly if the batteries suffer external damage by recognising voltage drops in real-time based on a range of scenarios. If the voltage drop is deemed to have been caused by damage to the battery, the phone will warn the user and initiate additional safety measures to prevent further hazards.

A series bi-cell battery design allows the same power to be delivered while lowering the electrical current and reducing heat generation. The internal series bi-cell design takes this concept a step further by combining these dual battery cells in the same structure, therefore taking up less space while still delivering the same safety performance.

Does increasing fast charging shorten battery life?

In general, battery life deteriorates with increased charging cycles regardless of the charging speed. Through years of research and innovation, OPPO has developed a technique capable of measuring and tracking the electrical potential of negative electrodes in real-time. Using this technique, OPPO can control the negative electrode potential within a reasonable range, thus intelligently keeping the maximum charging current within a safe range. Through this method, we can reduce the generation of “dead lithium” and ensure all lithium ions flow to negative electrodes from the positive side, meaning better battery life and charging speeds.

Through this technique, OPPO has also developed a brand-new smart charging technology that provides a charging experience that can better balance charging speed and battery life. By being able to determine battery conditions in real-time, the technology can automatically adjust charging power based on what is needed, providing an intelligently customised charging experience for users.

For example, upon recognising overnight charging, the technology will automatically turn to “relax” mode, helping extend battery life without compromising charging speed. While ensuring the speed of 65W SuperVOOC and full charge and discharge of the battery, it is also able to maintain 80% of its original capacity after as many as 1,500 charge cycles.

When can we see the acclaimed 65W AirVOOC released, and are there difficulties in producing it?

The technology is ready for commercialisation. We will keep you posted if there is any update.

Are there any health concerns when using wireless charging?

While we will continue to seek greater breakthroughs in the area of charging, users can be assured that OPPO’s existing systems and technologies that are in use today are adequate to ensure safe charging for our consumers. We do not foresee any health concerns related to the use of wireless charging.

In the midst of a climate crisis, why focus on wireless charging, a technology known to consume more energy due to heat loss?

OPPO’s goal is to make VOOC Flash Charge technology truly ubiquitous on a global scale, creating an all-round charging experience in all kinds of real-life scenarios. The development of wireless charging technology is to meet users’ abundant needs. Wireless Flash Charge, otherwise known as the AirVOOC, is wire-free and reduces the strain on the cable, making the charger easily portable, and saves the preparation time for charging as compared to conventional wired charging. Users will be able to choose charging methods — wired or wireless — based on what is most suitable for that scenario.

Are there plans for a more sustainable way to charge our phones in the future for OPPO?

Yes, removing the electrolytic capacitor from the charging system is OPPO’s attempt to provide a more sustainable way of charging. With this approach, the power quality is improved exceptionally, which minimises the harmonic distortion in the power system during charging and further reduces the electricity pollution. Moreover, chargers have become more compact and lightweight, making "high power, small size" chargers available for our users.

Credit: OPPO

We've seen fast-charging evolve over the years, from a measly 20W to 65W and even prototypes of 125W fast charging technologies. As always, necessity is the mother of invention. We're definitely looking forward to seeing even faster charging speeds from OPPO in the near future.

---

Written by Fitri Aiyub