OwnerChris
Owner's Other EV1976 Honda CB550F
LocationWashington, District of Columbia US map
Vehicle1969 Pearson 35 Sailboat
Hull #7 of this classic sailboat. Primary propulsion being sails makes an electric auxiliary very reasonable.
MotorD&D Motor Systems, Inc. Separately Excited DC
$975 300A 24-48V controller Kit from Thunderstruck.
DrivetrainSingle 15" Diameter, 13" Pitch, 3 Blade Prop driven by 40/18 reduction pulleys and 1" H series timing belt. Browning thrust bearing.
ControllerAlltrax DCX
300A. Allows reverse with the flick of a toggle switch and regeneration under sail.
Batteries8 Trojan T-105, 6.00 Volt, Lead-Acid, Flooded
220Ahrs @ 20hr rate, 185Ahrs at more reasonable 5 hour rate. Great (Large) size for house bank.
System Voltage48 Volts
Charger
Solar Bimini of (3)x205W 24V solar modules in parallel into solar charge controller. Batteries are charged in 24V mode only.
HeaterElectric space heaters when at shore. Heading to tropics when not!
DC/DC Converter TBD.
24V to 13.8V for 12V aux battery charging to run existing 12V systems. Lighting and inverter will be powered on 24V. As things need replacement, they will be replaced with 24V equipment.
InstrumentationCycle Analyst
Top Speed7 MPH (11 KPH)
In calm water with no wind. This will not power off a lee shore! The boat will need to be sailed to safety in that situation and I will have nice storm sails for that purpose.

Plenty of diesels clog up during rough weather when the tanks get shaken around. Bad news if you can't sail away!
AccelerationIrrelevant, but sufficient.
RangeAll to 50% DOD:
6 knots for 25 minutes. (48V only)
5 knots for 40 minutes. (48V only)
4 knots for 2 hours. (24V)
3 knots for 3.5 hours. (24V)
Solar motor sailing @ 4knots all day.
Watt Hours/Mile600 Wh/Mile
@4 kts: 100A @ 24V continuous.
Seating Capacity20. Sleeps 4 though. Plan to cruise with only 2.
Curb Weight13,500 Pounds (6,136 Kilograms)
Approximate weight will remain the same due to removal of diesel engine, fuel tank, etc. Balance should be improved.
Conversion TimePlanned 200hours over winter break, mostly removing diesel and cleaning 40 years of oil mess.
Conversion CostTBD.
Additional FeaturesBy designing to minimum marina needs and neglecting the desire to match the existing diesel power or range, the system cost and complexity are reduced 10x. This system is designed around the batteries and PV necessary for anchoring out for an extended time.

System is a 2 speed design, with 24V and 48V modes. A DPDT switch puts the (2) 24V battery banks in parallel (24V) or series (48V). Doing this allows several advantages.

The 24V mode can be designed to daily use in calm weather, anchoring out, better solar charging (parallel vs. series modules for shading losses), cheaper electronics, and more efficient battery use anchored out (24V equipment skips DC-DC converter losses).

48V mode should provide plenty of thrust for windy marina maneuvers. This is a ~5-10 minute mode and the battery banks will be equalized when put back in 24V mode (house loads will unbalance pack in this mode).

I may add a 9.9hp high thrust outboard to the transom later to push longer distances on the ICW and canals.
Sailboats should be sailed! I'd love to go without an engine, but asking people to tow me into every marina goes against the whole independence thing that attracted me to the lifestyle. This electrical system should be a nice compromise.

Project begins early November once my sailing season comes to a close.

code by jerry