Easily Upgrade from Fuel-Powered to Electric Boats

With growing environmental awareness and rapid advancements in new energy technologies, retrofitting traditional fuel-powered boats into electric vessels has become an industry trend. As a leading provider of marine electrification solutions, ExploMar offers modular, high-performance electric outboard systems—delivering efficient and convenient retrofit solutions. This guide details the process to help users complete upgrades smoothly.

Step 1: Assessing Power Demand

Before retrofitting, calculate your power needs based on actual use cases to ensure battery capacity matches requirements:

• Recreational use: Record typical daily cruising distances and add 20% safety margin. If fast-charging facilities are available at the marina, smaller battery packs may be selected for cost efficiency.
• Commercial use: Consider route distance, payload, cruising speed, and charging infrastructure. ExploMar’s technical team can provide accurate power demand assessments.

Battery consumption reference:
60 kWh ≈ 40 L gasoline; 90 kWh ≈ 60 L gasoline
Each outboard supports up to 2 or 3 battery packs in parallel.

Step 2: Boat Compatibility Check

Three key assessments are required before retrofitting:

1. Battery compartment space: Ensure the original fuel tank area can accommodate battery packs and meet load-bearing requirements, or you can retrofit the space to fit the battery packs.
2. Outboard installation position: The transom tilt angle must remain within 15° ± 2° and withstand thrust from the electric propulsion system.
3. Waterproofing: Proper drainage is essential to prevent water accumulation affecting electrical safety.

Note: Boats originally equipped with outboards mainly require battery compartment evaluation.

Step 3: System Installation

1. Tools & Materials

Lifting equipment (≥500 kg load rating)
Ø20 mm rubber cooling hoses
Special lubricants and coolant
Waterproof sealant and accessories

2. Outboard Installation Shaft length selection (transom–waterline distance):

<50 cm → S Series (20″)
50–70 cm → M Series (25″)
70 cm → L Series (30″)
Install it with supplied waterproof fasteners. Reinforcement plates are recommended for stress distribution. ExploMar systems are simpler to be installed than traditional ICE outboards.

3. Battery System Integration

Install packs in the fuel tank compartment, ensuring:
Balanced weight distribution
IP67 protection for the battery chamber
Proper center of gravity alignment
≥20 cm clearance for wiring channels
Secure with anti-loosening bolts

Cooling options:
Plate heat exchanger (optional)
Dual seawater circulation system (high-spec, optional)

4. Electrical System Connection

（1）HMI installation:

• When installing the 12-inch waterproof touchscreen, ensure the bracket is securely fixed to the boat structure using stainless, corrosion-resistant screws.
• The digital steering wheel must be calibrated to the neutral position, and steering limit settings should be configured after installation.
• The electronic throttle must be installed with smooth, unobstructed travel, and the emergency stop lanyard function must be tested and verified.

（2）Wiring:

• High-voltage harnesses (in orangecolor) must be secured throughout with dedicated clamps to prevent contact with the hull.
• Low-voltage control harnesses (in black) must be kept at least 100 mm away from high-voltage harnesses to avoid interference.
• All keyed connectors must “click” into place to confirm locking and be sealed with waterproof adhesive.

 （3）Cooling System Connection

• Before installation, check all rubber hoses for cracks or aged.
• Connection sequence: Battery → PDU → Radiator → Water Pump → Battery (forming a closed loop).

Note: After filling the system with coolant, use the display to manually start the pump’s air-purge operation until the coolant level stabilizes and the pump runs smoothly.

QC checks:

Allow cable slack to absorb vibration
HV cable bend radius ≥ 5× cable diameter
Verify coolant flow sensor ≥5 L/min before first start

Safety warnings:
Disconnect MSD main switch & wear insulated gloves before HV work
Cooling system pressure ≤0.5 MPa; never disconnect hoses under load
All electrical connections must be double-checked before powering on

Step 4: Commissioning & Acceptance

Pre-checks:
Verify HV/LV wiring integrity
Coolant level
Reducer lubrication

Functional tests:
LV power-on self-check (no error codes)
HV trial run
Low-speed sea trial
Steering/trim/tiltcheck
Charging system verification

Benefits after retrofit:
Noise reduced by 90% (≤55 dB)
Zero fuel consumption & emissions
Energy cost savings of 60–70%
Simplified maintenance (no fuel system servicing)

Step 5: Operation & Maintenance

• 3 full charge–discharge cycles for new battery packs
• Inspect fastener torque every 90 days

Safety measures:
High-speed operation locked out when the propeller is dry
Fast-charging requires to active cooling system
Steering auto-centers when outboard is tilted

Step 6: Service & Support

Users can access support via:
ExploMar official website
Authorized service network (on-site retrofitting available)
Standard retrofits can be usually completed within 24 hours. For complex projects, ExploMar certified service providers are recommended.