External drive on iOS 13: This Accessory requires too much power

With the newest version of Apple’s mobile operating system, iOS 13, you can now easily connect external hard drives (e.g. USB thumbdrive, keyboard, mouse) and manage files directly from your iPad or iPhone.

If you are using an adapter cable to connect a USB hard drive to your iOS device, you may be greeted with either of the following error messages:

Cannot Use Accessory

USB Flash Drive: This accessory requires too much power


Cannot Use Device

The connected device requires too much power

Why do I see this error message?

This error message is shown because your external device you are trying to connect requires power in order to function properly. The Lightening or USB-C port on your iPhone or iPad only will make a limited amount of power available to external devices. The error means that the external device you are trying to connect requires mores power than your Apple device can give: the maximum is 100mAh.

This is a simple Lightening to USB from Apple. It will only allow you to connect simple devices to your iPhone or iPad.


If the error message keeps popping up on your device, you may try to perform some actions first in order to resolve the issue.

Best thing to do is to first disconnect all cables that are plugged in. Plug in the adapter cable again, then connect the external device. Make sure each cable is connected firmly so that there is no weak or interrupted connection.

Another option you may try is to reboot your iPhone/iPad/iPod, both with and without the adapter cable connected.

A third option is to make sure your Apple device is fully charged.

Alternative options

Try another device

If you are still having trouble with the error pop-up, there are still some options to try out. First, you may check if the same error is shown on another iOS device.

Or, try another external device. Another USB thumb drive or external hard drive may work perfectly.

The last option here is to try a totally different device: more concretely, a very ‘simple’ device such as a keyboard. If the keyboard (which is a simple device and doesn’t need much power generally speaking) is working fine, it is likely you should keep reading.

Use a an adapter with a power supply

The last option remaining and your best option you have is to use a OTG adapter that has an additional power supply port available. This means that there are two ports in total: a data transfer port for your external device, and a power port (which will both provide additional power to the external device, and it will charge your iOS device).

Lightening to USB 3 adapter from Apple. Not only does it allow for faster transfer speeds, it will also allow you to connect external devices that require a lot of power (notably external hard drives).j

Thanks to the external power source, the external device you connect can now draw up to 500mAh, which is 5 times as much without extra power source.


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36 thoughts on “External drive on iOS 13: This Accessory requires too much power

  1. Pingback: Transfer video files from Windows computer to iPad without iTunes | Thomas' Miniblog
  2. What a disappointment! I’ve just tried four different USB memory sticks (including quality, branded Sony and Sandisk drives and a USB 2.0 device) with a powered USB adaptor (the “best option”) and all of them have returned the message “this accessory requires too much power”. I even made sure that the powered adaptor was charging the iPad first. I’m using a 2017 iPad Pro 9.7”, for this.

    I’ve heard rumours that USB adaptors from 3rd party manufacturers (this one was bought on eBay) are sometimes not fully compatible but, before I go to the expense of an Apple-branded adaptor, I’d like to be sure that I’ll get a better result from doing that. What are other people’s experiences?

    1. Hello,

      I just upgraded my iPad Mini 5 to 13.1.1 and receive the “not enough power” error message, even when using a genuine Apple USB adapter with the auxiliary power capability. So you can assume that buying the genuine article is not going to solve this problem, at least until Apple releases a fix (if that’s even possible).

      1. Using Apple’s powered USB 3 Camera Adapter, it works like a charm. Need to check your usb charger because no all chargers can power your device and the USB drive at the same time. You need more than 1A (5W) Charging Adapter.

    2. The same. Standard Apple branded Lightning to USB adapter won’t work with anything, just gives that error message. No way will I buy the powered one having wasted $40 already.
      Utter garbage

    3. Hello Stephane. Have bought the Apple adapter and still no luck reading anything – keyboard and usb flash drive. But……works perfectly on my iPhone. I’m going crazy with this. Have you found a solution ?

  3. Furious…iPad Pro second gen. usb lightning camera adapter. iPadOS. SAN disk cruzer blade requires too much power error despite being powered through lightning port. What a bunch of total crap

  4. I purchased the original Apple ‘Lightning to USB 3 adapter’ and have it powered by an iPad charger. The result is that I no longer get the error messages but whatever I stick into it is apparently not recognised as nothing happens. What do I miss here?

  5. Ok, I had the same issue. Found a work around. I have a generic ebay USB Lightning adapter with USB, SD and MicroSD.
    The “trick” I found was to attach the lightning power to the device and have it plugged in, then attach a non-powered USB hub to the USB port. Plug in your USB device (usb keys, keyboard etc) and for me it worked.

    Hope this helps someone.

      1. I read once that the iPad doesn’t simple provide “x” amount of power (100 mA, is it?), but it provides that amount of power *per port* in an attached USB hub. So, if you connect a 5-port USB hub (non-powered), the iPad will provide 5×100 = 500 mA to the entire hub. Then, if you connect a Sandisk USB stick to the hub, there is enough juice to power it.

        The above has worked for me since my 3rd gen iPad running iOS 5.1.1, and it still works on my 2017 iPad Pro 12.9″ with iOS 13.6.1 — my Sandisk cruzer alone requires too much power, but when I connect it via a non-powered USB hub with 5 ports, it works fine.

        I have Western Digital portable HDD’s (1 & 2 TB) that take more than 500mA, so they don’t work in the above scenario. Does anyone know about SSD drives — do they require less power than HDD’s, and will they connect successfully via a non-powered hub? I don’t want to invest in one if it won’t work with my setup.


    1. How strange. After hours and hours of trying everything. This actually worked. The usb flash drive now shows up on my files folder. Thaaaaaank youuuuu.

  6. the other fix I have found, so far, is that it will take things off an SD card with the Lightning-SD card reader. Of course, it’s another stupid connector…

  7. Ok now I’m kind of excited. I kinda fixed it!

    I tried using the original AC adaptor with my usb3 adaptor. now it works! But kind of crazy I would need that much power for a thumb drive. The USB hub I was using wasn’t cutting it. But my iphone SE can read the same device without any assistance.

    iphone. SE.

  8. It’s just pathetic. I can connect a usb to my android phone with no trouble but for my ipad with 4x the battery size, it ‘requires too much power’.

  9. Same problem here. I have spent 45€ in the original Apple adapter. It’s crazy that we cannot connect a simple pen drive to an iPad.

      1. I solved my problem. Now when I look back through the comments, I realize my answer was already here, but I had overlooked it. Maybe someone will read this and will be spared the days of frustration I went through.
        This only applies to attaching a USB flash drive to an iPad. Many commenters here are writing about iPhones, and that is a different situation.
        So here it is: when I purchased my iPad it came with a power adapter (charger) that has an output of 5V. Then I purchased the (45€) original Apple Lightning to USB 3 Camera Adapter, and tried to attach a USB flash drive, but I got the “requires too much power” message. Most USB 2.0 or 3.0 flash drives (I found out) require 500 mA to operate. When I purchased a 12W Apple power adapter (19€) and used that one instead of the “original” 5W adapter, my problem was solved. I can read USB flash drives on my iPad. So check the output of your power adapter, even if it is the original one that came with your iPad. Hopes this helps someone!
        Someone told me that iPhones come with 12W adapters, could that be the reason that commenters (such as Zing Poppo and ChrisLL) can only connect to the iPhone, not the iPad?
        The other possibility is to find a flash drive that runs on 100 mA or less, but then you don’t need the fancy 45€ powered adapter, a regular Lightning to USB adapter will work.

    1. I have iPad Air (3rd Generation) running IOS 13.3.1 and I got the “can’t operate USB due to power requirements” hassle. My iPad was charged to 80%, I congratulated myself for having the foresight to order the Adapter with the 2 inputs (USB & lightning, for power source), but even with a Power source plugged in to the adapter, it failed. I even had a non-powered USB hub to plug in, with the target USB inserted—-I really thought THAT would do it… but nope. Back to Apple for a refund—have to blow that 50$ on something else.

      1. Might I add: had I connected my original Apple wall-plug power adapter, the process might have been successful. But…! This isn’t what I want—If I am near a wall power source and WIFI, I can play the music on my USB any # of ways. I want the USB/iPad to play music on the fly… portably. If the iPad can’t read the USB without encumbrance, there is no value in paying 50$ for an adapter.

  10. Got it sorted. The (powered) Apple adapter worked with my Iphone pro but not with my iPad Pro. I realized I didn’t use an original Apple charger. Once I changed to using the original charger (the one that came with my iPhone Pro) the issue was solved. So the lack of power message you encounter on the iPad when connecting the USB adapter will be solved when you use a wall charger with a higher output

    1. This work you’re using the lightening to usb 3 there are outputs to 1 usb port and another lightening port. Simply charge your device through the adapter then plug in your usb.
      Portable charger works too. Not the most convenient thing, but if you can’t get a refund might as well do it :/

  11. Same here, but I kinda figured out to solve the issue I have found a generic micro sd card adapter to usb, external power was not required. The first adapter was a very common one, card entrance on one side, the other usb plug. This other that work out was very different, the same usb plug worked as the micro sd entrance. Weird, but it solved the issue.

  12. Hi,

    Connecting the simple genuine Apple lightning to USB Camera adapter to USB keys gave the same error message as soon as the USB key has 32 GB or more capacity.
    Using USB keys with capacity <= 16 GB is working fine.

    IOS 13.3, iPhone SE


  13. Yes, I don’t understand either… I’ve tried a 16 and 32 GB microSD card in a lexar USB reader and both say that the devices use too much power in the USB3 charging card reader. And the whole underpowered charger isn’t true because I’ve tried the original wall plug, as well as a 15W and 60W charger also.

  14. I have iPhone and iPad Pro. Both cannot read thumb drives. However, using a SD card with a generic adapter worked fine for both. I tested SD cards of 2Gb and 16Gb. Both are seen by the iPhone and iPad and content can be accessed. So, I will simply use SD cards or TF card as they require much les power than Thumb drives.

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