The modern water-motor community is increasingly discussing the transition to electric traction, and requests for boat-powered electric motor 20 hp They're becoming more and more common, and they're not just quiet trolling motors, they're full-fledged propulsion systems that can glid medium-sized PVC boats or steer boats confidently through calm water, but in the pursuit of sustainability and silence, many people are forgetting the nuances behind the 20 horsepower figure in the electric world.
Unlike gasoline, where power is a fixed characteristic of an internal combustion engine, it's more complicated in electrics, and it's where battery voltage, current strength and engine efficiency come to the fore. boat-powered electric motor 20 hpYou will have to choose a complex battery system, often requiring 48 or even 96 volts, which is often a stumbling block for beginners who dream of silently sliding through the water.
In this article, we will discuss in detail what is hidden behind the 20 hp marking in electric tractors, how to correctly calculate autonomy and whether it is worth the effort. We will look at the real traction indicators, operating features and compare them with traditional internal combustion engines, so you can make an informed decision about the modernization of your boat.
Real power: electric kilowatts vs. horsepower
The first thing that a customer faces is unit conversion, so if a gasoline engine gives out its 20 hp per shaft at certain speeds, then an electric motor is a powertrain. boat-powered electric motor 20 hp To get the equivalent of 20 hp (about 14.7 kW) per shaft, taking into account the efficiency of the electric motor (usually 80-85%), you will need to bring to the motor about 17-18 kW of electric power, these are huge currents that dictate their conditions for wiring and switching.
Many manufacturers use marketing tricks, indicating the "peak" power that the motor can only produce for a short time, or convert the power consumed from the socket to horsepower without taking into account losses. boat-powered electric motor 20 hp It's important to understand that electric thrust has a different torque curve: maximum torque is available immediately from zero rpm, making acceleration more sharp, but maximum speed is often limited by the design of the screw and voltage.
⚠️ Attention: Not all claimed 20 hp in electric motors are honest. Often manufacturers report power equivalent to propeller thrust rather than power per shaft. Always check your technical data sheet and look for the "Rated Power" in kilowatts.
Also, consider the voltage drop under load. If your battery jar is not able to deliver the required current without a drawdown, the actual power on the screw will be much lower than claimed. BMS system Battery Management System can simply turn off power when overloaded, which can be critical on water.
- ⚡ The nominal power of the motor should be at least 15-16 kW for honest 20 hp.
- 🔋 The voltage of the system is usually between 48V and 96V for such power.
- 🌊 The efficiency of the screw also affects the final thrust, electricity is not converted into motion with 100% efficiency.
Battery System: The Heart of Your Electric Motor
The choice of energy source is 70 percent of the success of an electrification project. boat-powered electric motor 20 hp It's been running for at least one hour at full capacity, you're going to need about 15-20 kWh. If you use lead-acid batteries (GEL or AGM), it's going to weigh more than 500-600 kilograms, making the boat unstable and dangerous.LiFePO4) assembly.
Modern. LiFePO4 The 20 kWh assembly will weigh about 180-200 kg, which is already comparable to the weight of a gasoline engine plus a full tank of fuel, but the cost of this solution will be 3-4 times higher than the engine itself. It is also important to provide a system of balancing cells and water protection, since lithium does not forgive errors in operation.
Special attention should be paid to connectors and cables. Currents in a 48V system at 15 kW reach 300 Amps or more. Conventional car terminals will melt in seconds. Anderson SB large-series IP67 Cable products must be flexible, with a cross section of at least 50-70 mm2, to minimize losses and heating.
Comparison with gasoline analogues: economics and ecology
When we talk about boat-powered electric motor 20 hpA gasoline engine of this capacity consumes about 6-8 liters of fuel per hour at full gas, an electric analog will eat about 15-18 kWh of energy. If you charge from a home grid, the cost of a kilometer of electricity will be 5-7 times lower than gasoline, but this is true only if you have access to cheap electricity.
In terms of service, the train wins by a huge margin, there's no oil, no filters, no candles, no timing belts, and no need to change the pump water. Boat electric motor All it takes is lubricating the bearings (and not all models) and checking the seals, and the lack of vibrations and exhaust fumes makes fishing or cruising with family much more comfortable.
| Parameter | Gasoline 20 hp. | Electric 20 hp (LiFePO4) | Comments |
|---|---|---|---|
| Weight of kit | ~45 kg (motor) + 20 kg (bak) | ~30 kg (motor) + 200 kg (battery) | Electric is much heavier due to battery |
| Range (full gas) | ~40-50 km | ~20-25 km (with a battery of 20 kWh) | Gasoline is still energy intensive |
| Cost of an hour's work | ~500-700 rubles. | ~100-150 rubles. | Electricity is cheaper when charging from the grid |
| Noise and vibration | High. | Minimum | The main plus of the trains |
| Term of service | 1,000-1500 motor-hours | 3000-5000 hours (for motor) | The battery will have to be changed before the engine. |
But there are downsides to electrification that the vendors keep quiet about: battery degradation over time and dependence on infrastructure, and if you go far away from civilization and drain the batteries, you can get back on gasoline by refueling in any garage, and you need a generator or solar panels to charge in days.
Installation and installation: technical nuances
Installation of the power system 20 hp It requires a professional approach. Unlike low-power trolling motors that can be simply screwed to a transom, it is a serious engineering challenge, not only to secure the motor itself, but also to ensure that heavy batteries are securely attached, that power cables are protected from rubbing and water ingress, and that the main fuse is installed.
☑️ Checklist for installation
Cable tracks must be laid so as to avoid the risk of damage by sharp edges of the boat hull. All connections must be soldered or pressed and protected by thermal shrinkage. For control often used remote gas pedal (RCE) or a tiller, which must also be connected by a quality signal cable, shielded from interference of the power line.
⚠️ Note: When installing lithium batteries, be sure to use a master switch with current vent, available for quick power outage in case of an emergency or fire.
It is also important to think about cooling if the batteries are packed in a sealed case. Lithium heats up at high discharge currents, and lack of ventilation can lead to overheating and shortened service life. In some cases, active cooling or heat-dissipating cells are required.
Operation in real conditions: speed and range
What can boat-powered electric motor 20 hp On a PVC boat with a length of 3.6-3.8 meters with one person on board, this power will allow you to get on plane and reach a speed of 25-30 km / h. However, the range at maximum speed will be limited to 15-20 kilometers. When the speed decreases to 10-12 km / h (cruising mode), the range increases to 40-50 km, which is already quite comparable to small-class gasoline analogues.
On heavier metal boats or Kazankas, 20 electric forces will only confidently keep the hull in displacement mode at a speed of 8-10 km / h. Full-load gleaming may not be available or require such a high energy consumption that the range will be reduced to 10 minutes.
Effect of the screw on efficiency
The choice of pitch and screw diameter is critical for an electric motor. Too much stride will create overload, too little will not allow you to develop power. For 20 hp, the optimal screws with increased diameter and pitch, specially sharpened for low torque revs, often 3-4 blade models.
Winter operation requires special attention. Lithium batteries are afraid of charge in the cold and lose capacity when discharged at low temperatures. motorboat All year round, the battery compartment should be thermally insulated, and charging should be carried out only in a warm room.
Overview of popular models and manufacturers
The market of electric motors is growing rapidly, and now you can find decent options with a capacity of about 20 hp The leaders of the segment are brands like Elco, Ep Carry, Navion Chinese models often offer better price-to-power ratios, but may be inferior in quality of materials and corrosion protection.
When choosing a specific model, pay attention to the Protection rating IP67 or IP68The motor has to withstand short-term full immersion. Also important is the type of control: there are motors with an integrated controller in lower unit, and there are motors with a remote controller, which makes it easier to maintain. The presence of a reverse and its smooth operation is another critical point for maneuvering.
When buying a no-name engine, be sure to request the possibility of a test run under load. Check whether the body of the controller is not warm after 5 minutes of operation at full gas.
Some models are equipped with built-in BMS With Bluetooth modules that allow you to monitor the residue of charge, temperature and error history directly on your smartphone, this is a very useful feature that helps you avoid a sudden stop on water due to an empty battery.
The main conclusion when choosing a model: do not chase the maximum declared power, it is better to take the engine with a margin of 20-30% of the design, so that it works in a gentle mode and less warm.
Frequently Asked Questions (FAQ)
How much does it cost to assemble a set of 20 hp?
The cost consists of the motor (from 40 to 100 thousand rubles. depending on the brand) and the battery. 20 kWh battery (LiFePO4) will cost about 250-350 thousand rubles The total amount starts from 300 thousand rubles and can reach 500 + thousand rubles. for quality components.
Can I charge this battery from a regular outlet?
It takes about 15-20 hours to charge 20 kWh with a standard 10 Amp charger, and you need to purchase powerful 20-30 Amp chargers to speed up the process, which require separate wiring in the garage.
Do I need to register an electric motor in GIMS?
Under current Russian legislation, small vessels with an engine of more than 8 kW (about 10.8 hp) are subject to registration. Since 20 hp is approximately 14.7 kW, such a vessel is a small vessel. motorboat The boat must be registered and the boat must be granted category M rights.
What happens if the motor falls into the water?
If the engine is certified IP68However, after extraction, you need to thoroughly rinse it with fresh water (especially if the water was salty) and check the sealing of the glands before the next launch.
Is the switch to solar energy for recharging realistic?
It's not going to be possible to completely switch to solar for a 20 hp engine, because the panel area on the boat is not enough, but installing flexible solar panels on the awning or roof will help compensate for self-discharge and add several kilometers of travel at long parking lots.