Safe and powerful batteries for the marine environment

Marine electric batteries – safe, powerful & waterproof

The ePropulsion range of marine electric batteries are designed for high performance and the harsh marine environment. These LiFePO4 electric outboard batteries and eSeries batteries offer cleaner power and are incredibly energy efficient.

The power range goes from 1 kWh to 144 kWh output (when used in parallel) to complement ePropulsion’s industry leading electric motors. All ePropulsion batteries can be charged at the same time as discharging power, with solar or hybrid generated power.

Spirit electric outboard battery

ePropulsion E Series batteries

epropulsion E80 4069 wh battery
Maintenance free

Plug, play and charge


80% less weight than acid or agm battery


Waterproof and shockproof

Space saving

75% less volume than acid or agm battery


Inherently safe chemistry. BMS protection


Recycling and redistribution is easy

E Series batteries

The high performance E Series batteries will power any ePropulsion outboard or POD motor, as well as other brands of 48V systems for marine propulsion, domestic or solar systems. All ePropulsion batteries are recyclable.

The batteries are designed for a long lifespan. Even when used daily over many years, you can expect a life of 3000 cycles to 80% of the original capacity.

The built in Battery Management System means that the cells will only discharge to a maximum safe level to protect and extend the battery life. When not in use, the batteries will ‘hibernate’ and discharge themselves, so there is no need for any manual discharging.  Up to 16 eSeries batteries of the same model can be connected in parallel to an ePropulsion motor and additional rechargers are available.

epropulsion E40 2048wh battery electric outboard
E40 – E Series battery 2kWh
epropulsion E80 4069 wh battery
E80 – E Series battery 4kWh


Why choose lithium iron phosphate batteries?


Read the blog

E175 – E Series battery 9kWh

E Series marine electric batteries – tech spec

2048 Wh LiFePO4* battery

4096 Wh LiFePO4* battery
8960 Wh LiFePO4* battery
WaterproofnessRobust waterproof shell (IP67 rated)
LongevityReliable battery management system - protects battery life
Battery lifeLong life span 3000 cycles at 80% DoD (depth of discharge)
Battery capacity2048 Wh4096 Wh8960 Wh
Rated voltage51.2V
Max continuous discharge current40A80A150A
Charging time: 110V charger2 hours 4 hours9 hours - one charger
4.5 hours - two chargers in parallel
Charging time: 220V charger2 hours3 hours6 hours - one charger
3 hours - two chargers in parallel
Rechargingmains, 12 volt, solar, wind, auxillary etc
Recharging with Hydro generationYesYesYes
Dimensions42 x 39 x 20.7cm
16.5” × 15.4” × 8.2”
55.5 × 44 × 21.2 cm
21.9” × 17.3” × 8.4”
50 × 51.5 × 26 cm
19.7” × 20.3” × 10.2”
Weight28 kg / 61.7 lbs48 kg / 105.8 lbs87 kg / 191.8 lbs
Series connectionN/AN/AN/A
Parallel connectionUp to 16 battery packs

All the E-Series batteries are LiFePO4 (Lithium Ion Phosphate). This makes them 30% lighter, but enables around 50% more usable capacity than standard AGM lead-acid batteries.

LiFePO4 batteries have a longer life of up to 3000 cycles. A typical AGM battery can only achieve 300 to 500 cycles.

Spirit integrated battery specification

Electric marine batteries for outboards

Battery Capacity: 1276 Wh – extensive capacity
Battery weight: 8.7kg

Rechargeable: 12 volt auxiliary output or solar panel
Regenerative charging: Yes – with Spirit 1.0 Evo
Charging time:
   Standard 8.5 hours
   Fast Charger 3.5 hours

Battery life: 500 cycles @ 80% DOD
Waterproof: IP67
Recyclable: Yes
Buoyant: will float if you drop it overboard
E series battery compatible

Change to electric powered outboards – clean efficient performance

All ePropulsion electric marine batteries are designed for maximum efficiency, performance and safety.

The affordable lithium E Series batteries are compact and energy dense and weigh 75% less than the equivalent lead acid battery. They are designed to achieve the most efficient unit price on the market, as low as $0.46 per WattHour.

Multiple E Series batteries of the same size can be connected in parallel, to increase power output. Each model has a different battery management system and cell configuration, hence only the same model can be connected in parallel.

The Spirit 1.0 Plus and 1.0 Evo electric outboard motors can be connected to the E Series batteries for longer range use, instead of using the integrated electric outboard battery.

It is possible to use a 3rd party lead acid battery with the ePropulsion range, although the ePropulsion motor will not be able to access real time battery status.

Comparison of E Series with AGM battery

The charts show a run time of an ePropulsion Navy 3.0 outboard at full throttle.

E 80 battery

ePropulsion electric motor battery E80 E Series
Run time at full throttle
81 minutes
4.8 kg
Cost per Wh
Retail RRP

4 x 12 volt 130 AH AGM batteries

Run time at full throttle
58 minutes
150 kg
Cost per usable Wh

Live test of ePropulsion E Series battery

Testing was done in a 26ft sailing yacht with a displacement of approximately 2 tons.

Set up with an ePropulsion 3kW motor and one E-175 series battery with a capacity of 9kWh.

750 W 4 knots
48 NM (nautical miles)
1000 W 4.5 knots
41 NM
1500 W 5 knots
30 NM
3000 W 6 knots
18 NM
Swallow yacht using ePropulsion electric motor