I was skimming through some Fairphone-Zendesk-Pages and there were at least two things, which caught my attention.
The first one is this:
Correct me if I’m wrong, but I thought proper English would be “What operating system (OS) does the Fairphone 2 run on?”
The second thing is in the topic Manually install Fairphone OS for the Fairphone 2. In approach 4 (“Flash the binary images from a computer”) it says:
[…]
3. Power off the device and take the battery out;
4. Boot the Fairphone 2 into the bootloader […]
[…]
5. Connect the Fairphone 2 to your computer;
[…]
This order of actions implies that one should firstly take out the battery, secondly boot the phone and thirdly connect it to the computer. Since I don’t see how this could make sense without a battery, I’d say the phone has to be connected to the computer before it can be booted into the bootloader. (Hence, 4 and 5 need to be swapped.)