I don't know about the other brand, but the tortoise never shuts down. It continues to draw around 10 milliamps (depending on supply voltage) whenever power is applied. This is what keeps the points tight against the rails. It also allows the use of series LEDs to indicate position.
10 or 20 mA will not hurt or even appreciably heat these motors. They will last a very long time under power - that's how they are designed to operate.
There is one concern: If you have a LOT of these motors, make sure that your supply can handle the total current continuously. Add at least 10 percent for a good supply and 40-50% for those cheap off shore wallwarts (they are generally overrated and will get hot / fail near listed load). IE 30 tortoises is only 30 x 20 mA at most. This is 600 Milliamps total. A 1 amp supply will be fine for such an application.
Karl
The mind is like a parachute. It works better when it's open. www.stremy.net
John
Dave
Just be glad you don't have to press "2" for English.
http://www.youtube.com/watch?v=zQ_ALEdDUB8
http://www.youtube.com/watch?v=6hqFS1GZL4s
http://s73.photobucket.com/user/steemtrayn/media/MovingcoalontheDCM.mp4.html?sort=3&o=27