Ideas for powering Devo12?

I was just thinking about my FRSky module sitting doing nothing, and I had an idea (like others have had) to install the module in my devo12. Problem is the devo12 runs off of a 1S pack and only runs around 3.8v

So what can I do to make the devo12 run off of a 2S pack?

I was thinking if I use a BEC at about 4v I could power the devo12 off the BEC and power the FRSky module straight off the 2S.

My concern is that when the 2S starts to get low, I won't be able to see that in the devo12 display because it would always show 4v (or whatever the BEC puts out).

The other thing is that I don't really want to modify the devo12 case in any way. I'd have to at least drill a small hole to get the telemetry data out of the case up to the little screen.

Anyway, if anyone has any ideas of how to safely power the Devo12 from a 2S please let me know.

Do the module really need 2S? There are dc-dc converters which can step up the voltage from 1S, if the module does not need too much current. Take a look at Maxim MAX756 or this module: http://www.ebay.de/itm/LM2577-DC-DC-Converter-Adjustable-Power-Step-Up-Boost-Module-LM2577S-/271168568739 .

I read around at hobbyking and found, that the module will need 6V, 130mA. There are some files linked at the module's page, one of them is this: Dx8 Mod by jj604 . The guy uses an usb converter - looks like a smart solution.