What is the best battery for an electric boat motor?
More and more boats in marinas equip themselves with electric motors. This trend brings its share of questions and in particular: what is the best battery for an electric boat motor? There are many types of marine batteries, each with their advantages and disadvantages. We explain all the differences in this article so that you can choose the battery that best suits the needs of your electric outboard motor. Indeed, some owners will favor the budget while others will favor the life of the batteries. Follow this guide to understand everything in the world of electric boat motors. You should also know that a boat license may be required for electric outboard motors over 4,5 KW.
Contents of the page
Why choose an electric motor on a boat?
Before'buy an outboard motor for your boat, find out about the legislation in force in your navigation area. Indeed, some areas such as natural parks are protected and it is forbidden to use gasoline or diesel boat engines. Other reserves prohibit heat engines for more or less long periods that coincide with the reproduction cycles of the animals so as not to disturb the fauna.
In these circumstances, the choice of an electric motor for your boat is worth considering. However, you should know that electric outboard motors are not recommended for boats over 4m. They are even generally used for boats of less than 3 meters...
Indeed, despite all their advantages (silent, vibration-free, environmentally friendly, light, etc.), electric outboard motors today are still not powerful enough to meet the needs of a boat over 4m long. .
In addition, electric boat motors are much more expensive and have very limited battery life, which limits boating time.
It should therefore be noted that a electric motor on a boat should not be used if:
- your boat is over 3-4m long
- you are looking for speed,
- you navigate in areas with strong currents,
- you have to travel long distance.
In summary, if your navigation area does not prohibit internal combustion engines, choose a gasoline outboard motor for your boat instead! We've written a guide to help you choose the best engine for your boat.
What electric motor power to choose for a boat?
As we saw in the previous paragraph, you may have no choice but installing an electric outboard motor on your boat. You will therefore need to invest in an electric motor with a suitable configuration in order to have suitable power and autonomy. So you have to ask yourself how far am I going to travel? On an electric boat motor, it is the capacity of the battery that influences your autonomy and your engine power. On thermal boat engines we speak of horsepower (HP), but for electric boat engines we measure the power in kilowatt/hour (kWh) or in pounds (lbs).
The formula to remember to find the right electric outboard motor power is:
Electric outboard motor power = Power required to propel the boat to its maximum weight
Which battery to choose for an electric boat motor?
We repeat, we do not recommend a electric motor for a boat over 4m because they have a very low power and autonomy. They are ideal for 3m boats such as tenders or fishing boats.
However, if you buy an electric motor for your boat, you will need to choose suitable marine batteries. There are 3 types:
- The lithium battery: it is lighter, offers more charge cycles (+5000), has no self-discharge and can discharge to 100%. But it is also the most expensive...
- The carbon lead battery: it takes up a lot of space, it is heavy but it resists extreme cold! Indeed the lithium battery does not work well below -5°C.
- The lead/calcium battery: it is the least expensive and the most common but it self-discharges strongly, it only has a maximum of 300 charging cycles and it cannot be discharged more than 50%.
It is therefore advisable to equip yourself with lithium batteries. Even if the initial investment is higher, the lithium battery compensates with a much longer lifespan. It is the best choice for a boat electric motor.
NB: it is important to have on board your boat a means of recharging the batteries (such as solar panels or a 12 V power supply for example) and/or to have a replacement battery. This is extremely recommended for your safety but also to increase your autonomy if necessary.
What is the best brand of electric motor for a boat?
There is no classification of best electric boat motor brands. Quite simply because all the big brands are equal. They all offer excellent engines and warranties of at least 3 years.
We can nevertheless name the top 3: there is the leader Torqeedo but also Minn Kota and Motorguide.
If you can't decide between them, the number 1 criterion for choosing an electric motor for a boat is the ease of maintenance of the motor and the speed of access to spare parts.
This is all the more important as the electric motors must pass a technical inspection every year to maintain the manufacturer's warranty. Plus, you don't want to wait months for your mechanic to receive a part if your electric motor fails...
So if you are sailing close to a workshop that does not service Torqeedo electric motors, then choose the preferred brand of this marine mechanic (Minn Kota or Motorguide).
Depending on the country, some brands are more present than others. It is therefore necessary to inquire in your port to find out which brands of marine electric motors have a maintenance network nearby.
Learn more about boat motors:
Should you choose an electric or thermal boat engine?
