The fastest boat electric motor: myths and reality

Finding the fastest boat electric motor often turns into chasing the numbers that manufacturers put in their booklets. However, real speed on the water depends not so much on the marking on the hull, but on a combination of factors, including the voltage of the system, the screw group and the aerodynamics of the vessel. Many anglers mistakenly believe that buying a model with maximum traction power automatically guarantees high speed, but this is not always the case.

Modern technologies have allowed to create units capable of accelerating light aluminum boats and PVC boats to 15-20 kilometers per hour, which was previously considered the lot of gasoline analogues. nominalBut also the efficiency of converting battery energy into propeller rotation, and in this article, we'll look at which models really deserve the title of speed and what to look at when choosing.

It's important to understand that speed in the context of electric power is closely related to the capacity of the batteries used. Even the most powerful motor will not show record results if the power source is not able to deliver the necessary current without a voltage drawdown. Lithium-Iron Phosphate (LiFePO4) batteries.

Technical specifications affecting speed

To achieve maximum speed, the voltage of the power system is paramount. Standard 12-volt motors are limited in power, so the fastest models almost always run from 24 or 36 volts. Increased voltage allows you to reduce current at the same power, which reduces the heating of the windings and increases the heating of the windings. Engine efficiency.

The second critical factor is propeller design. The rotor design is often optimized to save charge or noise, not speed records. Replacing the rotor with a large-step model or a modified blade geometry can give you up to 15-20% speed gain without replacing the motor itself.

⚠️ Warning: Installing a propeller with increased pitch on a weak battery can cause a deep discharge and failure of the BMS controller.

The electric motor, which can easily accelerate a light single PVC boat, will operate at the limit of its capabilities on a heavy metal flat-bottomed boat without reaching passport speed. Hydrodynamic resistance The hull part of the vessel plays a crucial role in the final measurements of the speedometer.

Market Leaders Overview: Minn Kota and Ghost

The company remains the undisputed leader in the segment of high-speed electric motors for many years. Minn KotaTheir flagship series, such as Ulterra and RiptideThey are equipped with digitally controlled engines that provide a smooth set of speeds and high maximum return. GhostIt was developed in collaboration with Mercury Marine engineers.

Series engines Ghost They are positioned as the quietest and most powerful in their class, and with their new engine architecture and improved cooling system, they can run at high speeds for long periods without overheating, making them ideal candidates for the fastest sports fishing unit.

• 🚀 High energy conversion efficiency allows you to keep the maximum speed longer.
• 🔇 The unique noise reduction system makes the engine almost silent even at full speeds.
• ⚙️ The digital control system accurately doses the power, preventing voltage surges.

And it's also worth noting that these motors are integrated with modern cartplotters and anchor systems, and that you can precisely control your speed through the cartridge. Head-Up Display Or a mobile application allows the angler to choose the optimal mode of movement, saving charge during the transition and developing maximum speed if necessary.

Comparison of thrust and real speed on water

You can often find tables that show thrust in pounds (lbs) and estimated speed, but these are reference data. The real picture depends on how the motor behaves under load. Some models with high declared thrust quickly "land" in speed when the headwind or current.

The table below compares popular high-thrust models and their approximate speed figures on a 4.2-meter boat with one operator:

Motor model	Traction (lbs)	Voltage (B)	Max. speed (km/h)
Minn Kota Ghost 110	110	36	14-16
Haswing Cayman B 12V	55	12	6-7
Watersnake ASP T24	24	12	4-5
Minn Kota Terrova 80	80	24	10-12

And as you can see from the data, going from 12 to 24 or 36 volts is a tremendous performance boost, and a 55-pound 12-volt engine will never overtake an 80-ft 24-volt engine, despite the lower thrust figure in the second model. totality systems.

Also, you should consider that manufacturers often specify the maximum speed in ideal laboratory conditions. In real water, especially with an overgrown screw or a non-perfect transom, the performance will be lower. Regular cleaning of the lower unit and screw helps maintain the declared specifications.

⚠️ Warning: Exceeding the recommended size of the screw may cause the stator windings to burn due to increased resistance to rotation.

Why does speed fall with time?

Over time, the neodymium magnets in the engine may lose some of their properties, and the bearings wear out, increasing friction, a natural degradation process that reduces the maximum speed of the motor by 5-10% after several seasons of active use.

The effect of the type of screw on speed indicators

The propeller is the only element that comes into direct contact with water and creates thrust. It's critical to get the propeller to speed at the right pitch. The propeller's pitch determines how far the boat will theoretically go in one turn.

Standard propellers that come with motors usually have a pitch designed for medium loads and economical travel. To achieve maximum speed, you often need to install a speed screw that has steeper blades. However, such a propeller consumes more energy and requires more powerful power. feed-in.

• 🌊 Small pitch screws provide better acceleration and traction at low speeds, but limit the "maximum speed".
• 🏎️ Large pitch propellers allow high speed but require more energy to start.
• ⚖️ Balancing the screw is mandatory: the imbalance will cause a vibration that will dampen the speed and destroy the lower unit.

Composite screws are lighter and often more aerodynamic than plastic screws, but are inferior to steel screws in strength. However, for electric motors, where there is no powerful torque of the ICE, steel screws are rarely used because of the risk of damage to the gearbox on impact.

Experimentally, it was found that replacing the standard propeller with a model with a step increased by 1 inch can add 1-2 km / h to the maximum speed if the engine power reserve allows.

The role of batteries in achieving maximum

The fastest boat electric motor is powerless without the right power base. Lead acid batteries (AGM, GEL) experience a significant voltage drawdown when speed is dialed, which leads to the fact that the engine does not receive the declared power and can not reach maximum speed.

Lithium-iron-phosphate batteries (LiFePO4They are capable of delivering high current discharge with little or no voltage loss at the terminals, which is why the powerful motor + LiFePO4 battery is the only solution for speed-driven people.

In addition to battery chemistry, its capacity and current output are important. For motors with a thrust of 80 lbs and above, it is recommended to use batteries with a capacity of at least 100 Ah at a voltage of 24 V or 36 V. The use of thin wires is also unacceptable - the cable cross section must correspond to the cable section. maximum current The engine consumption, otherwise the loss will be a significant part of the power.

⚠️ Note: When using lithium batteries, make sure that the built-in BMS controller supports the discharge current consumed by your motor at full speed.

You also need to consider the temperature regime. In the cold, the capacity of any battery drops, which is especially critical for lithium. If you plan to run at high speeds in the cold season, the battery should be insulated or kept warm until it goes out into the water.

Practical tips for high speed operation

Operating an electric motor at extreme speeds requires certain safety and technical regulations. Unlike gasoline engines, electric traction does not have the same inertia, but the jerk at start can be sharp. Always start at low speeds, gradually increasing the speed.

Control the temperature of the lower unit. If you run at maximum speeds for long periods of time, the windings of the engine and the gearbox heat up. Although modern motors have overheating protection, it's better to take breaks to let the system cool down. gearbox and wire insulation.

Keep in mind safety. High speed on a boat without a rigid hull (PVC) can be dangerous when faced with a wave or obstacle. Always use a safety cable (chek), which will stop the engine in the event of a person falling overboard.

• 🛡️ Check the condition of the lower unit regularly for cracks after high-speed runs.
• 🔋 Watch the charge indicator: at high speed, the discharge occurs very quickly.
• 🌊 Avoid driving at full speed in shallow water or grassy areas.

Remember, an electric motor is a complex appliance. Getting water inside a lower unit through the coils at high speeds (when back pressure is created) can lead to short circuits. Regular maintenance of the coils and replacement of the lubricant is a mandatory procedure.

Can I install an electric motor on a glidessing boat?

Yes, you can, but to go to the planing will require a very powerful engine (from 3-4 hp in equivalent) and a light boat. Most electric motors are designed for displacement mode, but some models are able to briefly bring light boats to the plane.

How often should you change the lubricant in the gearbox when driving actively?

When operating at high speeds and frequent loads, it is recommended to change the lubricant in the gearbox at least once a season or every 50 motor hours, checking it for metal shavings.

Do electric motors lose power in the heat?

Yes, when windings overheat (above 60-70 degrees), electronics can artificially limit power for protection, which reduces the maximum speed. Effective water cooling usually copes with this, but in fine warm water, the risk is higher.

Which screw to choose for maximum speed in shallow water?

For shallow water it is better to use screws with a protective casing or special shallow screws, which are less susceptible to overgrowth, but their pitch is usually smaller, which may limit the final speed.