Accu's voor elektrische buitenboordmotoren

Batteries for electric outboards

Electric outboards are becoming more and more popular and, due to continuous development, are getting better and more powerful. Your electric outboard battery can have an affect on a number of factors, including range and speed. Find out which battery is best for your electric motor, how to charge it and important tips on using batteries for outboards in this guide.

Batteries for electric outboard motors

Electric outboards are powered by batteries and rechargeable batteries, and depending on features such as an on-board computer, both can be used.

What is the right type of battery for an electric outboard?

The type of battery that should be used for an electric outboard motor depends, among other things, on the brand, type and size or power consumption of your electric motor. Key factors in choosing a battery are how long you want to run the motor, the weight of the battery and how easy it is to use. And of course, you have to make sure that the nominal voltages of motor and battery are the same.

All deep cycle battery types are suitable as power sources, such as lead-acid (consumer) batteries, AGM batteries or lithium batteries/batteries. Lithium-ion batteries have many advantages for electric motors. They're lighter, more powerful, can be charged quickly, used partially charged, are recharged effectively using solar technology and are cheaper to run in the long term. Lithium batteries for electric outboards are slightly more expensive than other types of batteries.

1 What type of battery does Torqeedo use?

Torqeedo has replaceable rechargable batteries and
high-performance lithium batteries
for their electric outboards.

2 What battery does a Temo electric motor use?

Temo outboards feature an integrated lithium-ion battery and do not require an additional battery.

3 What type of battery does Minn Kota use?

Minn Kota electric outboards can be powered by deep cycle lead-acid batteries, AGM batteries or lithium batteries, with lithium batteries being the most suitable for Minn Kota outboards.

4 What type of battery does Minn Kota 55 use?

All deep cycle lead-acid and lithium boat batteries are suitable for a Minn Kota electric outboard (trolling motor or auxiliary) such as the Minn Kota 55. The capacity of these 12 V marine batteries should be at least 110 Ah. Optimal results are achieved with lithium batteries, (LiFePO4).

Choosing the right battery for your electric outboard motor

To determine the required battery capacity.

  1. Look in the technical data of your e-outboard for the information on power consumption (watts).
  2. Determine the current (amps) required by the motor by dividing the wattage rating by the battery voltage.
  3. To calculate the amount of energy (ampere hours) required by the motor, multiply the
    pre-calculated current by the expected motor operating time (in hours).
    ATTENTION, the ampere hours (Ah) calculated here are not yet the required battery capacity! Remember that deep cycle batteries must not be completely discharged too!
  4. Next, determine the required battery capacity by multiplying the previously calculated Ah by a safety coefficient of 1.5, or better 2.

Don't forget that there are enormous differences in weight, depending on the battery type and size.

Tip: Instead of using a large and heavy battery with a very high ampere-hour rating, you can also connect two smaller batteries in parallel.

Think about the intended use of your battery. Bigger waves, stronger currents, more weight on the boat and higher speeds will require a bigger battery.

Tip: If you know that you like to be on the water for longer periods of time, go fast or your sailing times fluctuate greatly, it is best to always choose the next larger battery.

Why is it so important to get the
right battery?

Choosing the right electric outboard battery is important because you want to use it efficiently for as long as possible. The faster you go, the more energy and therefore more battery power you need. Only the right battery with sufficient capacity will get you where you want to go. If you don't want to be constantly buying a new battery for your electric outboard after a short time, you shouldn't use starter batteries, but only deep cycle battery types. Starter batteries can supply a very high current for a short time and are then immediately recharged by the alternator when the engine is running. They are therefore only discharged to a very small extent and are specially designed for this purpose. When used with electric outboards, starter batteries are discharged too deeply, which inevitably leads to premature wear and failure.

If you have any questions, please contact us. The SVB technical crew will be happy to help you.

outboard solar

How do you charge an electric outboard motor?

Electric outboard batteries must be regularly charged with charging cables or special chargers from the mains. Alternatively, a solar panel can be used to charge the battery while on the water. Get more use out of an outboard motor by carrying a spare replacement battery.

Charging times vary depending on the battery, charger, power source and discharge level. The approximate charging time for Torqeedo batteries is between 3.5 and 10.5 hours (with mains adapter). An integrated on-board computer shows you how far you can still travel. Minn Kota outboards have a battery indicator on the motor head. Battery status is also displayed on Temo electric outboards, and charging time for the integrated battery is approximately three hours.

Tip: Before storing, charge your outboard battery.

Important information on the use of outboard batteries!

Batteries must generally never be run completely flat or stored empty. Always take the time to charge your battery! The right charger also makes a difference to your battery's shelf life. It must be right for the battery, not be too weak and must have the correct charging characteristic (at least automatic switch-off or switchover to trickle charge).

To ensure that batteries are as efficient as possible and do not wear out prematurely, you should always take the manufacturer's recommended depth of discharge (DoD) into account. As a rule, you may discharge LiFe-PO4 batteries to a maximum of 80 %, deep cycle AGM or GEL batteries to 50 % and liquid lead acid batteries to 35 %. Proper care has a significant influence on the life of a battery and ensures that there is always enough power available. Make sure that your deep-cycle lead-acid battery is immediately and fully recharged or stored fully charged after each use. The main cause of premature failure of electric outboard batteries is that they are not fully recharged within 12-24 hours after use. To charge your boat batteries, use a suitable charger with an IU curve that can deliver a charging current of 10-15% of the battery's capacity.

Written by our SVB (technical) experts

Written by our SVB (technical) experts

Our team of SVB technical experts is there to give our customers professional advice on all matters relating to technology on board. Their expertise is the result of regular training and many years of experience.