While there are many ways you can transfer content to or from your Nexus 5, (see AirDroid or Samba Filesharing for Android) you can always attach an USB hard disk or flash drive to your phone directly.
For this, you need
- an USB OTG cable – USB On The Go – which looks like this
- You’d also need a USB Y-Cable, which looks like this:
The Y Cable is required because your Nexus 5 cannot supply the power required to run your USB device. If your USB hard disk is externally powered, you may be able to manage without the Y cable.
You also need an app that recognizes your external storage device. Total Commander is one that works, though you have to also download the separate USB device plugin. This is a 30-day trial or a 99-cent purchase.
After you install Total Commander and the USB plugin, open Total Commander, tap on the USB Stick link, and when it says “Reconnecting to USB device …”, plug in your OTG cable, the Y-spiltter and your hard disk. Plug in the free end of the Y cable to a USB power adapter, and you’ll see the contents of your device in Total Commander. You can now copy or move content to and off your phone.