How to Choose an Electric Outboard for Your Boat
Pick an electric outboard by matching its power to your boat's size and weight, then choose a battery big enough for the distance you need to cover. For an inflatable or small tender, a 500 W to 1 kW motor with a built-in battery (ePropulsion eLite or Spirit 1.0) is usually enough. Sailboats and heavier tenders up to a few tons suit 3 to 6 kW motors on a 48V battery (ePropulsion Navy or Pod Evo, Elco EP-9.9 or EP-14). Small powerboats that need to run faster call for the 96V ePropulsion X Series.
kW vs HP: what the power ratings mean
Electric outboards are rated in kilowatts. Makers also quote an equivalent gas horsepower, but that figure is a comparison, not a unit conversion. ePropulsion says its HP figures are a theoretical equivalent based on thrust and performance. By definition, 1 kW is 1.34 hp. Even so, ePropulsion rates its 1 kW Spirit as equivalent to a 3 HP gas outboard and its 6 kW Navy 6.0 Evo as equivalent to 9.9 HP. Elco compares its 4.8 kW EP-9.9 to a 9.9 HP gas motor. When comparing brands, look at kW, static thrust (where it is listed) and the maker's test data, not just the HP label.
Comparison table
Specifications are taken from ePropulsion and Elco published data.
| Model | Power | Gas HP equivalent | Voltage / battery | Motor weight | Control | Hydrogeneration |
|---|---|---|---|---|---|---|
| ePropulsion eLite | 500 W (750 W Sport mode) | 1.5 HP | Built-in 378 Wh, 25.2V | 6.7 kg / 14.7 lb | Tiller | Not listed |
| ePropulsion Spirit 1.0 Plus | 1 kW | 3 HP | Removable 1276 Wh pack that floats | 11.3 kg + 8.7 kg battery | Tiller | No |
| ePropulsion Spirit 1.0 Evo | 1 kW | 3 HP | Removable 1276 Wh pack that floats | 10.6 kg + 8.7 kg battery | Tiller or remote | Yes |
| ePropulsion Navy 3.0 Evo | 3 kW | 6 HP | 48V (39-60V), E-Series battery | 24.3-27.5 kg | Tiller or remote | Yes |
| ePropulsion Navy 6.0 Evo | 6 kW | 9.9 HP | 48V (39-60V), E-Series battery | 28.5-29.5 kg | Tiller or remote | Yes |
| ePropulsion Pod Drive 1.0 / 3.0 / 6.0 Evo | 1 / 3 / 6 kW | 3 / 6 / 9.9 HP | 48V (39-60V) | 6.2 / 15.3 / 31 kg | Remote | Yes |
| Elco EP-9.9 | 4.8 kW continuous | 9.9 HP | 48V (40-59V), owner-supplied bank | 65 lb | Tiller or remote | Not listed |
| Elco EP-14 | 6.2 kW continuous | 14 HP | 48V (40-59V), owner-supplied bank | 85 lb | Tiller or remote | Not listed |
| ePropulsion X12 / X20 / X40 | 12 / 20 / 40 kW | Not listed | 96V | 48-106 kg | Digital helm with electric steering | Not listed |
Battery voltage and capacity
Battery voltage is set by the motor. The eLite and Spirit carry their own lithium packs, so there is no separate bank to plan. The Navy and Pod drives run on 48V. ePropulsion recommends its E-Series LiFePO4 batteries, such as the E60 (3,072 Wh, 33 kg) and the E163 (8,345 Wh, 76 kg), both rated at 51.2V. ePropulsion's manual says the E-Series is tested to IP67. Elco motors also run on 48V, but the owner supplies the bank, and Elco suggests 90-120 Ah for the EP-9.9. The X Series runs on 96V.
For battery chemistry and bank sizing, see our marine battery guide.
Range and runtime math
Runtime in hours = usable battery watt-hours ÷ motor power draw in watts. Range = runtime × speed. Because power rises steeply with speed, slowing down extends range far more than adding battery does. ePropulsion's own test data shows this clearly:
- Spirit 1.0 (1276 Wh): 1,000 W gives 6.2 mph for 1 h 15 min, about 7.8 miles. 250 W gives 4.4 mph for 5 hours, about 22 miles. The math checks out: 1276 Wh ÷ 250 W ≈ 5.1 hours.
- Navy 6.0 Evo: 6,000 W gives 15 mph for 1 h 30 min (22.5 miles). 1,000 W gives 5 mph for 9 hours (45 miles).
- eLite (378 Wh): full power (500 W) gives about 45 minutes and 3.5 miles. Half power (250 W) gives about 1 h 30 min and 5.6 miles.
These figures come from light test boats in calm water: a 12 ft aluminum boat for the Spirit and Navy, and an 8 ft dinghy for the eLite. A loaded sailboat, a current or a chop will use more energy, so plan trips with a reserve. Sailboats gain little from more power once they near hull speed, which is why 3 to 6 kW moves many cruising sailboats well. Solar can top up the battery between trips. Our solar sizing guide covers the numbers, and the Spirit has a matching solar charger.
Shaft length
Measure the transom from the top of the mounting surface down to the bottom of the hull. ePropulsion's guidance:
- Spirit 1.0: Extra Short for 30-40 cm (11.8-15.7 in), Short for 40-50 cm (15.7-19.7 in), Long for over 50 cm (19.7 in).
- Navy Evo: Short for 40-50 cm, Long for over 50 cm.
- eLite: the shaft adjusts in four steps, from 282.5 to 401 mm on the standard model and from 432.5 to 551 mm on the long-shaft model.
Elco recommends its long shaft for transoms of 15 inches or more. On sailboats with a high transom or an outboard bracket, the longer shaft helps keep the propeller in the water when the boat pitches.
Tiller vs remote control
A tiller suits tenders and small boats where you sit at the stern. A remote throttle suits boats with a helm or cockpit steering. The eLite and Spirit 1.0 Plus are tiller-only. The Spirit 1.0 Evo and Navy Evo accept either the Evo tiller (Navy tiller handle) or remote controls: top mount (Navy remote control), side mount or dual throttle for twin installations. Pod drives are remote-only, because the motor is fixed under the hull. Elco offers tiller or Livorsi remote throttles. The X Series uses the X Series digital helm, with electric steering and power trim/tilt built in.
Regeneration (hydrogeneration)
Under sail, a hydrogenerating motor uses water flow to turn the propeller and recharge the battery. The Spirit 1.0 Evo, Navy Evo and Pod Drive Evo models support it, and the Spirit 1.0 Plus does not. ePropulsion's Pod Drive manual lists the conditions: the throttle at zero, the battery below 90%, the boat holding more than 6 km/h for 4 seconds, and an ePropulsion battery connected. Elco's outboard pages don't mention regeneration. For inboard repowers, the Electric Yacht QuietTorque 10.0sd saildrive offers adjustable regeneration and is recommended for boats up to 34 ft and 12,000 lb.
Weight and portability
If the motor has to come off the boat, weight decides a lot. The eLite weighs 6.7 kg without its bracket. The Spirit splits into a 10.6-11.3 kg motor and an 8.7 kg battery, so each piece is easy to carry, and the battery floats if dropped. The Navy (24-30 kg) and Elco (65-85 lb) motors usually stay mounted, and their 48V batteries are permanent installations. The X Series (48-106 kg) is a fixed powerboat engine.
Saltwater use
eMarine lists the eLite for use on lakes or in saltwater. All of these motors need the same basic care in salt water. Rinse with fresh water after use, tilt the motor out of the water when the boat is moored, and check the sacrificial anodes. Replacement anodes such as the Spirit clamp base anode and the Navy 6.0 Evo anode are stocked. Keep battery connectors dry and capped.
Which motor for which boat
- Inflatable dinghy or small tender: the eLite for short runs to shore (ePropulsion tested it on an 8 ft dinghy). The Spirit 1.0 suits longer runs or bigger tenders.
- Daysailer or small sailboat: a long-shaft Spirit 1.0 Evo, which adds hydrogeneration, or a Pod Drive 1.0 Evo mounted under the hull.
- Cruising sailboat, heavy tender or RIB: the Navy 3.0 or 6.0 Evo on an E-Series bank. ePropulsion lists the Navy for boats including yacht tenders, RIBs and yachts up to 5 tons. Pod Drive 3.0 Evo or Pod Drive 6.0 Evo models suit sailboats that want the drive under the hull.
- Jon boat, pontoon or small lake boat: the Elco EP-9.9 or EP-14. Elco suggests the EP-9.9 for jon boats, pontoons and sailboats up to about 25 ft and 2,500 lb.
- Small powerboat: the ePropulsion X12, X20 or X40 on a 96V system.
Torqeedo: Torqeedo publishes Ultralight (1-3 HP), Travel (2-5 HP) and Cruise (6-25 HP) outboard lines. eMarine currently stocks a few Torqeedo parts for existing owners, such as the magnetic key and the 1901-00 propeller for Travel 401, 801 and 503 models.
Browse all electric drives, or shop by brand: ePropulsion and Elco.
Questions & Answers
What size electric outboard do I need for a 10 ft inflatable?
For one or two people, a 500 W eLite or a 1 kW Spirit 1.0 is typical. The eLite is lighter and has a built-in battery. The Spirit's 1276 Wh battery has more than three times the eLite's 378 Wh, which gives far more range.
How far can an electric outboard go on one charge?
It depends mainly on speed. In ePropulsion's tests, the Spirit 1.0 covered about 7.8 miles at full power and about 22 miles at 250 W (4.4 mph). The Navy 6.0 Evo went 22.5 miles at full power and 45 miles at 1,000 W. Divide your battery watt-hours by the power you plan to run at to estimate runtime.
Is ePropulsion better than Torqeedo?
Both make tiller and remote electric outboards, so the right choice depends on the model and your boat. ePropulsion's Evo models offer hydrogeneration while sailing, and its Spirit battery floats. eMarine sells ePropulsion motors and batteries and carries Torqeedo spare parts.
Can I use an electric outboard in saltwater?
Yes. Rinse it with fresh water after use, tilt it up when moored, and replace the sacrificial anodes when they wear. Keep the battery connections dry.
What battery do I need for a 48V electric outboard like the Navy 6.0?
A 48V nominal lithium bank. ePropulsion recommends its E-Series LiFePO4 batteries (E60, E100, E163), which communicate with the motor and are required for hydrogeneration. Size the bank by multiplying your planned power draw by the runtime you need.
Can an electric outboard charge itself while sailing?
Some can. ePropulsion's Spirit 1.0 Evo, Navy Evo and Pod Drive Evo models have hydrogeneration, which recharges the battery while the boat sails. The Pod Drive manual says charging starts when the throttle is at zero, the boat holds more than about 6 km/h, and the ePropulsion battery is below 90%. The Spirit 1.0 Plus and Elco outboards don't list this feature.
If the battery cannot sit next to a Navy or Elco motor, a pre-terminated battery cable extension kit adds 10 ft of #2 cable.
Prefer a clear transom? Compare outboards, inboards and pod drives such as the 48V ePropulsion Pod Drive 3.0 EVO.