what are the maximum and minimum working voltages of the Bluetooth bee?
Hi,
The operation voltage of Bluetooth bee should be only 3.3V.For more details , please refer to our garden.
If you take a very(!) close look at the chips used in the bluetooth bee and look up their specs, you might find out that all chips (basically the flash and the radio controller) are speced to work from at least 2.7 volts.
(I did so because 3.3 Volts are hard to achieve using batteries)
In fact,my BB, purchased in spring of 2012, runs fine from 2.7 to 3.6 Volts. 
It ran even at 2.4 Volts, but the flash needed for startup is not speced for this low a voltage, and if you are starting up the bee from below 2.7 Volts the flash MIGHT, in theory, be erased accidentally if you are in VERY bad luck.
But this is not official, the chips might have been changed, and your mileage may vary…