I think most of these installations have a large genset to charge the
batteries (besides being able to do so under sail--although reducing your
speed). This replaces 2 heavy auxilliary engines and 1 diesel genset. That
would reduce maintenance, but you do lose back-up reliability.
Not sure how much the battery capacity is, but a much higher voltage is
utilised for the drive motors.

wrote in message
. net...

http://www.cata-lagoon.com/420_pres_uk.php

Does this make a lot of sense ?

I like the idea of using the propellers to charge the
batteries while under sail but the extra batteries make
the boat heavy (heavier than a Beneteau 473) and can
only run the motors for 2 hours.

Are there other production sailboats built this way ?