Well done for remembering P = V × I from GCSE Physics. (y)
Proprietary charging for the Oppo family. I use this exact charger for my Realme which I bought from Amazon Spain a while ago.
Why? It's there a dodgy chip situation?
I didn't know.. I'm gonna look at every charger now :) cheers
You'd want the OnePlus WarpCharge 30W chargers for the newer devices up until the OP8 series and the Nord. The new OP9 ones I believe use a 60W charger so they'll be different. I think this charger is good up until the OnePlus 3 until the OnePlus 6T. I believe 30W was from the OP7 range This charger will still give some degree of faster charging to newer OP devices, but just not the full potential. I've still got an old brick lying around from my OP3, and it shows with the bolt when I charge it on my OnePlus 8 Pro. But should always aim for the correct charger for your phone's make and model imo.