QUOTE(RDoe @ Jun 25 2017, 08:31 PM)
Interesting... Should it be charged at 1A?
Care to explain how the difference is like, as I've only thought that 1A is slower and 2A means I don't have to wait too long. Which one would you recommend, 1A or 2A?

i think the most basic is, let say iPhone 7 with 1960mAh battery
1960mAh * 5V / 1000 = 9.8Wh
using stock charger output 5V/1A = 5W
9.8Wh / 5W = 1.96 hours to fully charge
*there will be overhead, energy loss due to heat and etc..., dont expect it to be less than theory above

normally 80% efficiency is quite good
if you using higher Amp charger, let say iPhone 7 draw 1.5A@5V
that will be 9.8Wh / 7.5 = 1.3hours
there are lots other android device can be charge at 9V/1~3A, but not iPhone, just not yet

huawei new phone can charge at 5Amp, but don think it is 9V/12V, the current draw will be too much to handle the heat i believe
but still have to bear in mind, most device charge from 0 to around 80% at peak current, after that may slow down... to reach 100%, so the hours calculated above just for reference
some additional note for device charging is all about how your device
draw current, if your device can only draw 5W, if you use higher output charger will not helps, same here it WILL NOT harm your device due to your device will ONLY draw the current it needs