Etek Electric Outboard Motor Project
version 2.1
Making an electric Sneakeasy a little faster
I still haven't addressed prop efficiency but I've made a few updates which include:
A custom dashboard
The dashboard is made from aluminum plate and has been engine turned. The panel markings are custom vinyl transfers. The instrumentation includes an hour meter on the left. The rectangular gauges are from the left, a voltmeter which can read each battery voltage individually by rotating the selector switch, a main voltmeter to read the remaining battery charge available, and a digital ammeter to read the current draw of the motor. The switches on the bottom are for the bilge pump, running lights, horn and the main system key switch.

A custom made pot box
The PWM controller is managed by this custom made pot box. I machined it out of aluminum billet to house the 5K potentiometer gear driven at l:3 ratio and engine turned the cover. The 3 position toggle switch mounted on the side is used to select forward and reverse

An upgrade to 48 volt controller and the installation of a reversing contactor, A finished battery compartment
The last test was conducted at 36 volts and I added two more batteries so the system is now running at 48 volts. The battery boxes have been modified and the batteries are covered by hatches which have been removed for these pictures. six batteries are behind the driver's seat and two more located under the driver's seat. The total weight of the batteries is 500 pounds. To direct the power, I'm using a rebuilt model 1206 12 - 48 volt 275 amp Curtis controller purchased from EV Parts. It originally probably saw use on a golf cart. The reversing contactor came from a forklift scrap yard and was used on an electric industrial pallet jack. It has 24 volt coils, with 300 amp contacts  Behind the clear plastic window are the main system fuses. They are rated for 225 amp and a spare element is mounted. The main system disconnect, not shown, is a 24 volt aircraft SPST relay with 300 amp contacts

We went back to the lake to see how the 48 volt system performed
The top photo shows the boat trim at low speed. The bow is in the water and with the batteries and driver aboard, she trims out well. The small size of the ETEK motor is pretty apparent in this view. The second photo shows sneakeasy at speed with the nose slightly out of the water. The batteries were topped up and a speed of 10.4 miles per hour was recorded by a Garmin GPS. The current draw was 125 amps. 
The Test Data from this trial
Weight as tested approximately 1175 pounds
Full power one person - 125 amps, 48v, 10.4 mph - 8.05 hp input

After the single person speed test 4 more passengers were added and a short cruise was undertaken. The results were:
Weight as tested approximately 1975 pounds
75 amp draw, 48 volts, 6.5 mph -4.82 hp input
Note: This was not a full throttle run just a leisurely cruise with 5 hefty passengers

Battery rating- 75 amps for 108 min.
Go to update page. I got the bigger prop made click here
email: jmrudholm@psnw.com
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