As long as the charger state smart charging, u can use it to fast charge right? Any brand will do?
Nope that is not true... manufacturers can put whatever terminologies they want and in the end, will not deliver the technology.
qualcomm's quick charge 2.0 is only supported by chipsets. not any tom dick and harry charger can do it.
As indicated, compatible adaptive fast charger must fulfil 2 electrical features:
1) 9V and 1.67A
2) 5V and 2.0A
If the 9V and 1.67A feature is not indicated, confirm plus chop that is not a compatible fast charger which uses quick charge 2.0.
Don't ask me why got 2 features, all i can tell you is that the technology utilises a chipset which will fast charge at 9V at first, then trickle charge it at the end at 5V. This is why initial charging phase is fast (claims to charge 0-50% in 30mins) while you will realise 90% to 100% is kinda slower...
Also, the 5V and 2A feature indicates it is compatible to all other mobile devices using microusb to charge, thus enabling cross platform compatibility..