huh, it IS possible to change the transmitter battery mid cycle without putting in a new sensor. i forgot to change mine until just before it died. just requires waiting for the machine to catch up, hitting 'reconnect' and telling it no, you did not insert a new sensor.... and it's back on track. the trick is replacing the battery and getting it back on the sensor in under a minute. which, considering the fractured state of my transmitter battery compartment, was a little scary. now i just have to remember to call them tomorrow and ask about the status of replacements.