I have some info from an email conversation with the man (Jochen) behind the Torcman 685 motor that is used in Torqeedo 4.0.
He stated that the rewinded Torcman 685 is no more efficent than 75% at 4KW output. At good midrange (1.5KW) it peaked at 85%.
That means the Torqeedo 4.0 has to dissipate approx 1333W at 4KW full blast, consuming 5333W from the battery bank.
I wonder if Torqeedo 4.0 has some kind of time limit recomendations for the use of full power?
The Torcman 685 is an outrunner and they are even more difficult to cool as the windings sit far away from the water cooled casing.
A few years back ago I found some statements at various forums from a couple of guys that had burnt their Torqeedo's.
Some guy burnt the electronic controller, another guy the motor.....maybe they are safer today?
At 2:12 in the Torqeedo 4.0 video at youtube it can be seen consuming 5459W when going at planning speeds with approx 4KW output.http://www.youtube.com/watch?v=2gIACjevcRw
This confirmes the inefficiency of the electric motor used by Torqeedo.
They should develop a motor of their own that was at least 95% efficient at top speeds......that is the minimum
efficiency I'd expect from their highly priced outboards if I was to be interested in a deal.