May I allow a couple of facts to get in the way of all these stories about receiver packs and what they power? Thank you...
Most people use about 3000 to 4000 mAh from their main packs. Using the 4k figure to make the maths easy, that's about 500mAh per minute. At which rate, if the receiver pack were providing anything other than power for speedo, receiver, servo and PT, then it would last all of 30 seconds for a 250mAh pack. Since they last at least eight minutes...
As for the speedo re-charging the receiver pack, that is going to be a little on the difficult side. The speedo is a three-phase controller with BL, not a single phase controller. Unless it had a converter in it, there isn't any way a three phase supply can charge a battery. Since the converter would occupy as much space as the current three phase controller, speedos would be a lot bigger. Since they aren't...
What BD have done is to provide a plug for the incoming power to give life to all the electrics in the car bar the motor. This is no different to using the power from the main battery, which is how all the other speedos do it. The difference seems to be that BD will allow this power to come from either source, or maybe it just adds the receiver pack to the incoming cell and its regulator will take inputs up to 12v (2S + 1S) as the Tekin can.
Sorry that these facts may blow quite a few posts out of the water. I wait for the flaming to begin, but honestly chaps, these are the facts. HTH
