What's the difference between OPPO's VOOC flash charging and vivo's dual-engine fast charging?

OPPO's VOOC flash charging and vivo's dual-engine fast charging are both fast charging technologies. VOOC flash charging is a fast charging technology independently developed by OPPO. It has 18 patents and many authoritative certifications including Swiss IEC, which increases the fastest charging speed by 4 times and has impeccable intelligent full terminal five-level protection. VOOC flash charging is the world's first commercial fast charging scheme for mass production. Compared with other fast charging schemes, the technical threshold is higher, and VOOC flash charging requires customized adapters and batteries to be used together. OPPO has customized special adapters, batteries, data lines, circuits and interfaces, and has developed intelligent all-terminal five-level protection technology for this purpose, which is impeccable in safety.