Torqeedo Electronics

Several years ago, I decided to decrease my carbon footprint and replaced my gasoline-powered Mercury outboard with an electric outboard - - a Torqeedo.  The Torqeedo is powered by a battery bank that has 24 DC volts.  To accomplish this, I wired two group-27 12-volt batteries together in a series to generate the needed 24 DC volts. 

There was plenty of room in the fuel locker located under the portside cockpit seat.

The installation went as planned... including the hard-wiring in of a smart charger to keep the battery bank ready and fully charged.
The only drawback to the system is that while there is enough amps in the battery bank to motor from Bayview to Sandpoint (~30 nm) at about 3 knots, to go any faster will draw down the batteries quite quickly.  And, the faster I want to go, the faster the batteries are drawn down.  So, a couple years ago, I decided to put a second battery bank in the boat...  but, where to put two more batteries was a tough decision.  I finally decided to put the new battery bank (again two group-27 batteries and smart charger) under the cockpit sole.  There was enough room for a custom-made battery box and for the smart charger.

The second battery bank has been just what I needed.  And, no more worries about running out of "juice" on a long motor.

Last summer I added a "Off-1-Both-2" battery switch and a battery monitor that shows both the amount of charge (volts) and the amp draw for the battery bank being used.  Both of these are mounted on the inside of the transom. 
I could not be happier.

This is the schematic view of the whole system... not to scale...  The next decision is whether to try to figure out a solar charging system for days when I won't be able to plug into shore power to recharge... or if I should invest in a small Honda gen-set.
All-in-all, I am quite pleased with the Torqeedo and the whole outboard system that I now have.  It is quiet, and has no gas fumes.  Plus the outboard itself only weighs about 40 lbs. So, it easy to take off the bracket and put inside the boat for winter storage... and back on next spring.