Another member  posted this question and I have a related follow up question. 
I would like to eliminate the rechargeable internal battery on the TinyTV mini and wire it to an external 3 to 5v external DC power source. The external wire connection would have an ON/OFF relay .   Does this sound possible?   The reason is that the TV is to be installed in a model that I will NOT have access to once the TV is installed.  Thank you. 

Sorry if im gonna post on an old thread, and idk if this is also applicable to Tinytv mini but for my case, Tinytv 2, I just opened up the back, unplugged the battery, re-assembled, and at the moment, I have it plugged on the usb cable and turned on for the whole time I'm gonna work. If I don't update here, it means it still works.