This sign refers to the support of lightning fast charging function, the minimum is to support 5v2a fast charging, if the charging head marked 9v2a, it is to support the dual engine fast charging function.
If the one Plus mobile phone is charged with flash charge, there is a lightning icon and a blue breathing light, which represents flash charge.
The lightning symbol is a nickname for flash charging. Lightning is a flash charge. A lightning bolt in the battery. It's just a normal charge.
There is a special icon, which usually looks like a double lightning bolt