iPhone 4S will not charge faster
I tested the iPhone 4S. I can't confirm the iPhone 5 (I don't have one) but I'm almost certain it isn't any different.
I used this USB Power Meter I got on Amazon.com
http://www.amazon.com/Centech-USB-Power-Meter/dp/B00DAR4ITE
I also double checked by splitting open a cable and using a digital multimeter (ammeter.)
iPhone 4S draws 0.93 amps when rapid charging (screen off) and 1.03 amps (screen on.) That's 5 watts (at 5 volts USB.) It does so on the 10 watt iPad 2 charger, 5 watt iPhone charger, as well as 11 other 3rd party adapters including a 15 watt adapter.
iPad 2 draws about 1.98 amps rapid charging with the screen on and 1.87 amps rapid charging (at 5 V) with the screen off.
So I can say without a doubt, an iPhone 4S will never charge any faster with any adapter over 5 watts than it will with the 5 watt adapter. Again, I can't say for 100% certain that the iPhone 5 is the same but other evidence I've seen indicates it is the same.
The iPhone limits itself to using only 1 amp during rapid charging. That's all there is to it.
Also note that some super cheap 3rd party cables, especially super long ones will restrict power flow to less than 1 amp (5 watts.) So stick with MFI certified, name brand, or genuine apple cables or you could see slower charging on all adapters.
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Well, the actual current draw is limited by the device (Phone), not the charger, unless the draw is greater than the charger can provide.
If the iPhone can draw 6w instead of the 5w in the specs. then it would charge faster with an iPad charger. All one has to do is test. I have both chargers but I don't have any interest at this point.
Agreed.
And as I mention in my previous post the iPhone will actually spike up to 1.05 amps even from from the 1 amp charger when initially connected and quickly (within a few seconds) settle to 1.03 amps with the screen on while charging. It uses about 0.93 just rapid charging with the screen off.
So one might see a rounding up to 6 W as the iPhone pulls just slightly over 5 W depending on how they measure the power draw.
If they used a watt's up like they did in the youtube video, then they may be seeing overhead of the actual adapter converting the power to DC which might be just enough to bump it to 6 W when it's actually delivering 5 W to the phone.
I measured the actual amperage on the 5 V USB power line. I did over 50 tests with different cables and adapters with the same exact results every time.
Pretty much end of discussion.