Calculating the battery power needed for an electric boat involves a few steps and depends on factors like your motor’s power, desired running time, and voltage system. Here’s a step-by-step guide to help you determine the right battery size for your electric boat:
Step 1: Determine Motor Power Consumption (in Watts or Amps)
Electric boat motors are typically rated in Watts or Horsepower (HP):
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1 HP ≈ 746 Watts
If your motor rating is in Amps, you can calculate power (Watts) with:
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Watts = Volts × Amps
Step 2: Estimate Daily Usage (Runtime in Hours)
How many hours do you plan to run the motor per day? This is your runtime.
Step 3: Calculate Energy Requirement (Watt-hours)
Multiply the power consumption by the runtime to get energy use:
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Energy Needed (Wh) = Power (W) × Runtime (h)
Step 4: Determine Battery Voltage
Decide your boat’s battery system voltage (e.g., 12V, 24V, 48V). Many electric boats use 24V or 48V systems for efficiency.
Step 5: Calculate Required Battery Capacity (Amp-hours)
Use the energy need to find the battery capacity:
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Battery Capacity (Ah) = Energy Needed (Wh) ÷ Battery Voltage (V)
Example Calculation
Let’s say:
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Motor power: 2000 Watts (2 kW)
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Runtime: 3 hours/day
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Voltage: 48V system
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Energy Needed = 2000W × 3h = 6000Wh
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Battery Capacity = 6000Wh ÷ 48V = 125Ah
So, you'd need at least 48V 125Ah battery capacity.
Add a Safety Margin
It’s recommended to add 20–30% extra capacity to account for wind, current, or extra usage:
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125Ah × 1.3 ≈ 162.5Ah, round up to 160Ah or 170Ah.
Other Considerations
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Battery type: LiFePO4 batteries offer higher energy density, longer life, and better performance than lead-acid.
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Weight and space: Important for small boats.
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Charging time: Ensure your charging setup matches your usage.
Post time: Mar-24-2025
