On Mon, 15 Nov 2010 13:33:33 -0800, Mark Borgerson
wrote:

At least I think I arrived at the proper conclusion----that
you only need to use about 133 Watts continuously to require
quite a large alternator to recharge your house bank in
4 hours. In tropical waters, you might reach that load on
refrigeration alone---particularly if you want ice in
your cocktails! ;-)

There are lots of good reasons for having a large alternator but it is
almost impossible to fully recharge your house bank in 4 hours if it
has been drawn down to any great extent. With any luck you can get
through the bulk stage however to the 80 or 90% level.