Author: Bruce Loxton

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Solving the Power Problem with Catamarans – No Genset

Catamaran at night no genset
Catamaran with 3kW solar replenishing lithium batteries

Frugal, Moderate or Bold Energy User?

A 50-55ft Catamaran with 2 people will use 10-20kWh of energy per day. This may be a combination of gas and electric. If it’s all electric as the trend is with induction cooktops and combination air fryer/ oven, then it may be closer to 20kWh of electrical energy per day.

3kW of solar in the aft region of the boat free from general sailing shadows will yield 15 -18kWh in good weather in summer.

The challenge is the 20% of the time when solar yield is poor. Fortunately when the yield is poor, the skipper may be relocating with the engines running. It’s during this time, there is opportunity to capture a ton of replenishment power. 

The Secret is Rate of Replenishment Power

Charging at 10kW from the engine gives 5kWh every half hour. Running from two engines gives double that. That means in one hour engine time, on both engines you have recovered 18-20kWh. Thats the same as you would get from solar in perfect weather all day! So run the water maker, spa heater, all electric cooking and electric pizza oven. We have you covered.
Hybrid Alternator and catamaran no genset

Maximum Power is 23kW from Two Units

Charging at 10kW from the engine gives 5kWh every half hour. Running from two engines gives double that. That means in one hour engine time, on both engines you have recovered 18-20kWh. Thats the same as you would get from solar in perfect weather all day! So run the water maker, spa heater, all electric cooking and electric pizza oven. We have you covered.

Bidirectional Motor Generator

This is no ordinary alternator. If you are familiar with EV’s, their motors are synchronous with AC to DC inverter drives and run in regen mode.

This hybrid unit is based on a permanent magnet generator. However for precise control over a wide range of speeds, some field excitation is introduced.

In a brushed 48V alternator,  a direct current (DC) flows through field windings on the rotor, creating the necessary magnetic field.

In this unit, permanent magnets and electromagnetic field windings are combined to generate the magnetic field. The permanent magnets provide a constant baseline magnetic flux, while the field windings, located on the stator (and NOT the rotor), allow for dynamic adjustment of the magnetic field. This design often eliminates the need for brushes and the digital inverter control changes the excitation and power output very precisely.

Hybrid Synchronous alternator with high power

Comparison of BMG Technology with Alternator + Wakespeed.

 FeatureHybrid 48V 300A Peak Permanent Magnet Alternator with Scotty AI (HESA)Traditional 48V 130A Alternator with Wakespeed 500 remote field control.Winner
 “Alternator” TypeHybrid Excitation Synchronous Generator
(permanent magnets + hairpin windings)		Field-excited rotor onlyBMG
Rotor Design16 permanent magnets
+ excitation windings		Field windings onlyBMG
Power Density1.65 kW/kg (advanced hairpin)Lower due to round-wire windingBMG
IP Level

Brushless Motor: IP25.

Waterproof Inverter: IP6K9K

Generally Brushed

IP23 or lower

BMG
Dual Stator DesignDual three-phase, 30° shiftedSingle three-phaseBMG
Ripple Current ReductionSignificant (30° phase shift)Higher rippleBMG
Noise Vibration Harshness PerformanceOptimized (low ripple and torque smoothness)Higher NVHBMG
EfficiencyHigher (permanent magnets + hairpin winding)Lower (field-excited losses)BMG
Fault ToleranceDual stator allows operation in partial failureSingle stator, no redundancyBMG
 Peak Generator Power12 kW6.2 kWBMG
Peak Efficiency≥85%60–70%BMG
Power at Idle
(engine ~600RPM)		3.0kW300-500W TypicallyBMG
Continuous Power Hot≥5.5~7.0kW kW5~7.0 kWBMG
Maximum Speed18,000 RPM~8,000–10,000 RPMBMG
Operating Temperature-40°C to 105°C-20°C to 80°CBMG
Lifetime Expected10 years, 300,000 km, 8,000 hrs5–7 years, 150,000–200,000 kmBMG
 

12V and 48V Isolation

Negative side Earth isolated

YesNoBMG
Integration with Factory 12V or 24V AlternatorFull Integration for added power as solar backup at idleNoneBMG

Diagnostics and Protection

Of Load Dumps

Inverter/motor diagnostics,
100% load dump protection		Limited and depends on BatteryBMG

ISO 26262 ASIL B

Automotive Safety Standard

CompliantNot compliantBMG
Insulation GradeGrade H (180°C)Grade F (155°C)BMG
Hybrid synchronous alternator maxim output power
Scotty AI V3 and the Hybrid Alternator or BMG
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Electric Boats – Request for Quote – GC Boat Builder

Safiery released RFQ for Gold Coast Boat Builders considering electric propulsion for recreational boats

Project aims to position Gold Coast as leader in electric boat propulsion.

Zero Cost Electric Propulsion

Solar Charging at Home on the Dock will set the cost to charge to ZERO.
Virtually ZERO maintenance cost.

Fully Redundant Lithium Batteries

2 Independent Trains - Peace of Mind

SOLID STATE TECHNOLOGY

Proven System Integration

Partnering with Bosch Engineering, these electric boats will have automotive proven system integration between the power system and the 400V Lithium Battery.

Safiery will develop and supply.

  • Twin Solid State Lithium Battery Trains at 71kWh each.
  • Solid State Lithium is high density as used in EV’s at a minimum of 330Wh/kg (Safiery Core Product for Future)
  • Power Distribution Unit with each train that operates independently.
  • Safiery Monitoring of each and every sell for Minimum cell Voltage, Max Cell Voltage and Mn/Max Cell Temperature.
  • Energy Flow Software on wrap screen> Time to Go (Safiery Core Product for Future)
  • 230V on board (Safiery Core Product)
  • Electric BBQ, hot water, espresso, air-fryer
  • STARSHIP digital Switching and monitoring (Safiery Core Product)
  • Waterless Toilet (Safiery Core Product for Future)

Bosch will supply

  • Motors
  • Inverter
  • EDCU
  • Charger
  • Display Software
  • EDSP Pack
  • Global Support