albert: i would have thought it would be the other way around...the Micra is designed to use a 3v battery and boost it to the required voltage, while the Mini is designed to take 6v and step down the voltage.
The regulation circuit in the Micra is only capable of boosting the voltage, if you use a power source that is greater than the Vf of the LED, the circuit does nothing.
The R123s are 3.6v stock, or 4.2 with a modified charger.
Of course, JSB has some new and improved cells on the way, so they might well be testing these, in which case nothing ive said is relevant, because i dont know the specs of the new cells yet.
Maverick: we are talking about these: