Aerial view of REACH at Caterpillar IslaThe REACH at Portland Wooden Boat Festiv8HP ETEK adapted to 25HP Tohatsu powerhe
OwnerMyles Twete
Owner's Other EVs1920 Milburn Light Electric Model 27L
1911 Hupp-Yeats
2011 THINK City
LocationPortland, Oregon United States map
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Vehicle1988 Sam McKinney barge cruiser
26' wooden scow barge cruiser
Plywood, epoxy&glass construction
MotorBriggs and Stratton Etek Permanent Magnet DC
8HP at 48 Volt; Capable of delivering 14HP
for short intervals
Drivetrain1980's 25HP 2-stroke M25B Tohatsu outboard
long-shaft converted in 2003 to electric;
Standard outboard nom. 2:1 ratio.
ControllerAlltrax AXE4834
with EZ-GO Inductive Throttle Sensor
Batteries10 other THINK Enerdel 3kwh, 12S4P (31 - 48v), 31.00 Volt, Lithium-Ion
All 10 modules connected in parallel, for
nom. 700ah capacity, 42v, 30kwh
Each battery is composed of 2 Enerdel Vigor-
type 12S2P 42v/35ah modules and 2 Enerdel
RLEC BMS boards w/CAN interface.
System Voltage42 Volts
Charger Vicor Megapac 48v power supply
Megapac loaded with up to 6 Modupac 48v/4a
modules. Multiple Megapacs can be
connected in parallel also...limit is the
power source---can only draw about 30amps
or so if using 2kw genset (1.6kw max
continuous) while underway. Shoreside,
limit is similar at about 1.8kw
HeaterOlympian 3100 BTU catalytic propane heater
DC/DC ConverterGeneral Electric Rated for 36v to 12v, still using it for 31-48v in
30 Amp (36v rating) to 12 Volt
InstrumentationXantrex Link10 E-meter with RS232
Top Speed8 MPH (12 KPH)
7kts at 48v/200a for short bursts...6kts max
continuous at about 5kw.
Accelerationquick enough...probably 0-6knots in 20-
Range66 Miles (106 Kilometers)
60 n-mi at 5kts, 12hrs w/2.5kw
Watt Hours/Mile480 Wh/Mile
Approx speed vs power:
7kt: 10kw
6kt: 5kw
5kt: 2.5kw
4kt: 1.3kw
Seating Capacity16 adults
Curb Weight4,000 Pounds (1,818 Kilograms)
Conversion Time3-6mos operational, ongoing improvements for
first 3years thru 2006. Conversion to
lithium ~ 2013.
Conversion Cost$3000 for electrification...not including
the Honda genset. Big cost: boat slip rent.
Converting to lithium has cost about
Additional FeaturesHonda EU2000i 1.6kw continuous ultraquiet genset used for long
cruises (greater than 50mi). I have cruised 90miles round trip
with this unit up and down the Columbia river. Used approx.
9gallons of fuel on trip, for approx. 10miles/gallon fuel
efficiency at approx. 3.5 knots average. Since going with
lithium storage, won't need to bring the genset along unless
doing more than 55-mile run....

Swinging a 12x12x3 brass prop in a 14" Propguard nozzle
May 2023: More optimization is possible.

Prop: Going to 14x11x3 prop would likely increase efficiency
significantly. Currently watching developments and prices/options
for toroidal props as applied to boat propulsion.

Motor: After 20 years, still using Briggs&Stratton ETEK brushmotor.
Brushes were worn out on 3 brush sets and replacements were long
gone until 2022 when they appeared at ThunderStruck Motors (where I
bought the ETEK originally) as new items. So I bought 3 more for now, no new motor for me. The ETEK brush motor
probably runs at 85-90% efficiency and is easily air cooled.
Certainly a brushless replacement can be purchased that meets
performance goals and boosts efficiency to 90-93%, but the
improvement/cost just doesn't seem justified.

code by jerry