Are they self canceling :o
Yes. From their site (the FAQ):
"If there is no on/off switch, how can I be sure I won’t waste the battery?
If the signal is not blinking, they’re already off! The gloves wake up from their off state whenever they detect that the contact pads are pressed together.
If I throw the gloves in my backpack and the contact pads get stuck pressed together, won’t that drain the battery?
The gloves will automatically shut themselves off after a set period of time of being on to prevent the battery from draining in situations like these."