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Authenticated Apple devices can charge at up to 2100mA x 5V. Apple-non-fast-charging and non-Apple devices are relegated to much slower 500mA x 5V charging. Thus, while my OnePlus One phone itself supports a 5V charging current of up to 2000mA, it is not possible to charge at higher than 500mA.

Does a method exist to increase the available "Extra Operating Current (mA)" from 0 to the max value possible? I am interested in both OSX and Android related solutions.

Related but not helpful post here.

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I can confirm that for my MacBook Pro, charge current is increased above 500mA when using a POWER ONLY cable.

My understanding is that if the phone is connected via a POWER & DATA cable, the 'consumer' negotiates with the host for how much current is passed over the cable. When the negotiation asking for higher current is not successful, the available current is reduced to the standard (USB 2.0 defined) 500mA amount at 5V.

In the case of the POWER ONLY cable, no negotiation can take place and thus, the maximum usable current is provided by the host to the client or 'power consumer'.

Some observations...

  • When running on battery power (±80% state of charge), my early 2015 13" MacBook Pro (2x USB 3.0 ports) was able to charge my OnePlus One (±60% state of charge) at a maximum current of about 1750mA.

  • No change in charging current was observed when the laptop was connected to the mains or powered by the internal battery.

  • No change in charging current was observed when switching from one USB port to the other.

  • During the phone's charging process, keeping the screen ON resulted in an average charge current of about 700mA. When the screen was kept OFF, the average charge current increased to about 1750mA as previously mentioned.

  • As the phone battery reached a higher state of charge, the charge current was gradually reduced. At 67% state of charge, the maximum current was 1650mA. Note that this is consistent with the general behavior of lithium ion batteries. The battery controller will reduce the charge current in order to reduce the stress the battery's chemistry experiences during repeated cycling.

  • According to another answer, using a thunderbolt-powered USB hub in combination with a POWER & DATA cable seems to achieve higher charging currents as well. This, however, requires an additional dongle which is a solution I did not prefer.

  • The following is taken from an answer to Why is charging from computer using USB slower than using an outlet?

    The reason your android device draws less power from your USB connection than from a wall adapter is because of the USB specification. This can be side-stepped by shorting the data wires in in the USB cable, which will switch the phone or tablet into wall mode where it can draw the full available current. The amount of current available will vary considerably from PC to PC.

    The reason the specification exists in the first place is that the voltage to the computer's USB ports is usually supplied via the motherboard by a single loop connection which services all of the USB ports at once. Being only a few microns thick, this circuit is not able to deliver the same current as a dedicated charging wire. It is highly improbable that you will 'burn out your motherboard' by trying to draw the full available current through this circuit (although it is theoretically possible if your computer was a total P.O.S. to begin with). What is more likely to happen is that you will exceed the manufacturer's design specification, thereby denying sufficient power to any other USB devices you have connected, and/or other internal circuits which can cause the PC to crash. This is the very same reason it is recommended you use powered USB hubs.

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  • Not true. It is not SAFE to just pass the maximum current possible when there is NO NEGOTIATION between host and device. It's the opposite. Max 500 mA is offered as per USB2+ specs if no negotiation happens. What allows >0.5A and sometimes even different voltages than 5V, IS NEGOTIATION. Different devices have different protocols to do this, for example Apple and Android have different ways to ask for "fast charge". So the solution is usually a USB firmware feature or an OS USB driver's feature. See for example motherboard manufacturer apps that enable this even after rebooting.
    – Paul-Sebastian Manole
    Commented Jun 2, 2021 at 10:52
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Andreas Spiess, the YouTuber with the Swiss accent, has a great explanation/demonstration of how QC chargers use USB data lines to tell a charger/host to change voltage thereby increasing or decreasing charge current, enabling balance between charging speed and battery health.

In USB-C as specified in version 1.3 this functionality migrated to a dedicated serial line. Apple, having often followed their own path, should now be falling into line with official specifications.

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  • While this didn't answer the question at hand, the video is super useful for diving into the plethora of information on this topic. Thank you for sharing :-)
    – Martin
    Commented Apr 30, 2020 at 11:32
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Sorry for that. You can't.

Apple has pretty much built a lot of standards on its own, and Apple devices communicate in their own way. So your Mac is happy to recognize an iPhone or iPad, but never an Android phone.

Maybe get a good charger for your OnePlus One?

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  • Yes, that is what I have assumed to be the default but if the limitation is software-based, it should be possible to reverse engineer and override. The reason for the question is that when I don't have my charger with me, I use my macbook as a battery pack.
    – Martin
    Commented Oct 5, 2018 at 9:24
  • @Martin Even if the limitation is software-based, given Apple's close-source on everything, it's unlikely to be "cracked".
    – iBug
    Commented Oct 5, 2018 at 9:26
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IMHO theoretically it should be possible because usually power delivery via USB means that source and drain mutual agree on the maximum power consumption.

But what happens if drain (the phone) just ignores the agreement (or does not agree at all) and just consumes the power? AFAIK the OSX computer will deliver it, because usually the power is just available and I never heard of any computer that actually measures the power consumption on the USB port (if somebody has different info on that topic just correct me). You just have to make sure to use the correct USB port because otherwise you may damage the port if the phone tries to consume more power than the USB port physically can provide.

There you may want to try special USB cables (or an adapter) that only connect the power lines but not the data lines. Using such a cable the Android device may think that it is connected to a power plug instead of a computer and uses a higher charging rate. Depending on the phone charging type the USB data cables may need a certain resistor connected to ground or +5V - this is the way some phone identify special fast charger.

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  • Thanks for this comment. I tried your suggestion out and can confirm that the way to get around the 'negotiation' of power to be delivered while having the ability to transfer data is to use a 'power-only' cable.
    – Martin
    Commented Oct 7, 2018 at 10:23
  • @Martin: If my answer solved your problem please accept it enable the check mark on it's left side and/or upvote it.
    – Robert
    Commented Oct 7, 2018 at 14:53
  • Thanks for the answer. It led to me to learning more about the problem and therefore, I wrote up an answer which I think is more comprehensive than what you have provided. If I could accept two answers, I would also enable the check mark on yours. Have a great day.
    – Martin
    Commented Oct 9, 2018 at 14:58

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