Samsung Galaxy S7 and the Galaxy S7 Edge has got massive batteries this time. They have 3000 mAh and 3600 mAh non-removable Li-Po batteries respectively. This large battery is capable enough to power the Galaxy S7 for more than a day under normal usage. Basically the power rating of the Galaxy S7's battery is 3.85V which can power any USB storage device like flash drive, OTG drive, some external hard drives like the latest Samsung Portable SSD T3 which weighs only 51 grams. Galaxy S7 fully supports OTG function and you can even connect a USB mouse, keyboard or a PS4 or XBOX ONE controller.

The good news is that you can charge your Galaxy S6, S5 or S4 with your http://androidtabletgadgets.blogspot.com /2016/03/how-to-install-flash-player-on-samsung-galaxy-s7.html" target="_blank">Galaxy S7 or S7 Edge by just inter connecting them with cables. You can also move data by this method. See the image below.

Requirements

You should have at least one of the below mentioned USB storage or peripheral devices.

USB Storage: Any pen drive, flash drive or SanDisk OTG drive for android.
External Hard Drive: Portable SSD T3 or SSD T1 (250 GB, 1 TB or 2 TB)
Peripheral Devices: Keyboards, wired/wireless Mouse or game controllers.
USB OTG connector supplied by Samsung.

How To Connect USB Storage Devices To Galaxy S7

Take the USB OTG cable or use the adapter that came with your phone.
Plug in the storage device in the bigger USB port.
Connect the smaller port to your phone.
On connecting a notification will appear on your phone.
Now you can use any file manager app to copy or move files to and fro.
If you are using a Portable SSD T3 then you will need the official app for it that you have to install it on your phone. I will discuss about it later.
You can connect a keyboard, game controller and a mouse similarly.
For connecting a wireless mouse you should connect the USB nano-receiver to the OTG cable.
Switch ON the wireless mouse and it will work.

Note: I haven't tested a wireless keyboard and mouse combo with a common USB transceiver. But since the wireless devices are battery powered then the keyboard and mouse combo will also work. With this combo you can use a mouse and keyboard simultaneously on your Galaxy S7 or Galaxy S7 Edge.

Use Your Galaxy S7 As a Power Bank

With such a massive battery you can use your Galaxy S7 and S7 Edge as a Power Bank for charging other android smartphones. Since the micro USB port of S7 is not of Type-C, still you can charge your other smartphones. For this purpose you will need a normal data cable and an OTG cable/adapter. See the image below for connection.