batdog,
Read the "Parallel Operation = Reliability & Flight Time" in the link I have provided above.
There are visual and audible alarms offered by Tower:
http://www3.towerhobbies.com/cgi-bin...&I=LXHDJ2&P=RF
http://www3.towerhobbies.com/cgi-bin...&I=LXSZ87&P=RF
The second one saved one of my planes that developed an electric problem in the air, which was associated to vibrations.
Since then, I check my Voltwatch's lights while moving the sticks and with the engine running.