Quote Originally Posted by Andy from Sandy View Post
This is not long enough IMO and unless you are running the engine at a moderate to high speed will not get enough heat into the engine. I think you will be better served just leaving until you can get out and ride.

I can find no evidence of that.

AFAIK what it does do unlike a trickle charger is stop charging completely and monitor the voltage of the battery. When voltage drops to a set point it starts to charge. This is why it is called a tender and not a charger.
15 mins isn't long enough, I agree. Bike should be run till engine is good and hot. Usually about 30+ mins, with the engine going through a variety of revs in its range.