OPPO has developed "flash charging" technology to drive the industry's standard for fast charging, installed on its Find7 smartphone. Evaluations were conducted by outside agencies to compare the OPPO Find7's "4x" VOOC fast charge technology to the Mi 4 smartphone’s fast charging technology. The conclusion is that the OPPO Find7's flash charge is indeed faster than the Mi 4’s fast charge technology; to completely recharge its battery, the Find7 took 1 hour and 20 minutes, while the Mi 4 took 2 hours and 30 minutes. The Mi 4 currently uses Qualcomm’s Quick Charge 2.0 fast charge technology.

How to achieve fast charge?

The so-called “fast charge” refers to the increased input voltage. Normal 5V chargers can give way to voltage up to 9V, 1A of the same current, with the charging power nearly doubled. The original 5V 1A may have to charge 2 hours, while a 9V may only take one hour.

Bump Technology staff said that using O2Micro’s boost controller (Boost) enables them to support battery voltage of 8.4V. In the case of the same current, the power can be doubled. "In fact, in our large, single-string battery charging current, we use two strings of high voltage batteries under the same power to charge the improved battery. However, two strings are a problem as USB 5V cannot give two charging strings. Under normal circumstances, one cannot have two groups of USB 5V charging the battery. If done using fast charge technology, one would still need a 9 to 12V high-voltage charger.”

"Fast charge told us that quick charging is one differentiating factor for OPPO," the booth staff said. "Voltage is 5V; this technology is designed to increase the current from your adapter USB cable to the phone."

But this has resulted in another problem. The USB interface cannot have a current requirement above 1.5A. If you restrict the current, the only way to achieve the fast charge function is to increase the voltage. Charging using the highest spec adapter goes to 20V, and the power coming from the highest can reach 65W. The advantage is that the future of an adapter to the phone, tablet, laptop, and other devices can be done with a charging adapter.

Wireless fast charge?

The industry is generally worried that fast-charging battery technology will cause damage to the battery. The staff said that the key here is batteries. Using traditional batteries will definitely cause losses. New batteries solve this issue through different formulationsand processes. In addition, the power management system determines if the connection meets the fast-charging standard. If not, it will be automatically switched to the traditional small current charging mode.”

In addition to wired fast charging, the wireless charging technology is becoming more and more popular, and is also beginning to support high current charging. But the reps also said that they are not optimistic about wireless fast charging field. One concern is the strong appeal of USB organization; the future will gradually unify around a USB interface. Additionally, the charging efficiency is not high, loosely coupled with strong radiation. Some reports say that Xiaomi will use the next generation of mobile phones or bump technology to provide fast charging solutions, which is something to watch out for in the future.