Lithium battery for my boat
Torqeedo, ePropulsion, Victron Energy and Co
Popular lithium batteries for the boat
You can easily find the right battery type and model for your boat in the categories. "Which lithium-ion batteries are available for my boat?" - Here you will find almost all manufacturers and models available on the market for maritime applications.
You are not sure which lithium battery is the most suitable? Give us a call! We have a selection of 100 different lithium batteries from over 10 manufacturers.
Differences of the individual lithium cells - What do I have to pay attention to?
Lithium batteries are available in various sizes and capacities. You will find all variants from 0.1 kWh up to 112 kWh capacity in our shop. There are no upper limits, but the battery should be designed sensibly. Depending on your requirements, you need about 0.5 kWh of power per tonne per hour in displacement mode, and exponentially more in gliding mode.
The batteries are connected directly to the motor via cable. The closer the batteries are to the engine, the less loss is caused by cable lengths. If you have any questions about cable thickness, we will be happy to help!
The control of your electric boat engine runs as you know it, using a tiller or remote throttle and steering wheel. Depending on the control you have a display with information about speed, remaining range, current battery capacity and current/voltage.
Up to 1.8 kW, you will find electric outboard with an integrated battery. Thanks to Plug & Play the models are much more comfortable, flexible, and user-friendly. For more power, you need an external battery which is connected to the electric drive. Here we recommend any size depending on the application.
Weight of the lithium cells
Depending on cell technology or production used, lithium batteries have a different weight. As a rule, one kWh should not weigh more than 10 kg. There are lighter and heavier batteries, depending on the cell technology. .
Especially for gliding boats you should tend to the light ones, for the others the weight per kWh is often negligible. In any case, you should make sure you have a comfortable weight to carry if you have to transport the battery frequently.
Prices, brands and cell technology
The prices depend on various factors. A price per kWh of 500 € to 750 € is reasonable. In individual cases, prices above 1,000 € per kWh are also possible, which are justified by special certificates or security technologies. The quality cells from Sony or Panasonic are recommended. But also the cells from CATL, CALB or Winston are good to use.
Most lithium-ion battery packs are manufactured based on lithium iron phosphate (LiFePO4). Depending on the type of battery, different compounds in combination with yttrium or sulfur are possible. In general, batteries are very safe because they are not flammable. Besides, they also have the longest life span of all cell technologies available on the market.
Alternatively, there are NMC and NCA batteries that contain cobalt. The advantage of these batteries is a higher energy density. The disadvantage is a shorter service life and that they are flammable. Where low weight is important, these cells can be used.
Charging cycles of a lithium battery
The charging cycles can vary greatly depending on the workmanship and quality of the individual cells. The charge cycles are usually indicated by a degree of discharge. (DoD = depth of discharge) The deeper the batteries are discharged, the shorter the charge cycles. At 80% DoD, good lithium batteries (LFP) last 3000 cycles. For most batteries, this results in service life of over 10 years, depending on use. Batteries made of NCA or NCM often last for slightly fewer cycles (500 to 1000). Regardless of the number of cycles, batteries are subject to a calendrical life span, usually, you lose about 4% per year.
Monitoring and control of the battery with BMS
The BMS usually monitors the state of charge of the battery. This is shown on a small display in most cases. Other important parameters are voltage, charging and discharging currents and the temperature during charging and operation.
The most important features of the BMS are the functions for securing the single cells. The functions are deep discharge protection, overcharge protection, temperature monitoring, or fuse protection in case of short circuits. Otherwise, the battery management system provides load limitation, cell balancing, and takes over a large part of the communication.
Lithium batteries for boat engines - Which manufacturers are there?
Most boat owners are familiar with Torqeedo with the bright orange logo. Torqeedo comes from Starnberger See in Germany. Torqeedo is the market leader in the field of electric boat drives and has already delivered more than 100,000 electric motors all over the world. Torqeedo also offers the matching boat batteries.
In the leisure sector, the battery models are very popular with matching motors. Torqeedo, ePropulsion, Aquamot, RiPower, or edyn offer their battery packages. Especially the newest battery models from ePropulsion offer the best conditions with an unbeatable price-performance ratio..
Use of lithium batteries
We always recommend a complete package from one manufacturer to save additional costs and ensure functionality. Some electric motors, however, do not have their batteries, since virtually all batteries can be combined with the motor.
If you use your boat as a rental company or in the industry for commercial purposes, we recommend specially designed batteries from the premium segment. Aentron offers a special certification and is one of the only suppliers here. Often these are installed in combination with herbal products in ships.
The same applies to higher travel times (50+) per year. The lithium cells from Otherwise, Victron Energy is also a manufacturer with very high-quality components. In this case, it is recommended to use the matching battery in addition to the chargers of the market leaders.
Advantages and disadvantages of lithium compared to AGM
A big advantage is the depth of discharge and the capacity that can be used per kWh. Lithium batteries can usually be discharged to 95%. Depending on the technology, AGM batteries are damaged at 50% discharge and should not be deeply discharged.
Furthermore, a lithium battery weighs only a third of an AGM battery. Also, lithium batteries with up to 3000 cycles have a longer life compared to AGM batteries with mostly 750 cycles. LiFePO4 batteries can also be charged and discharged quickly without degrading performance. The only disadvantage is the higher price, which is significantly higher. The bottom line is that the advantages are clear for the lithium battery, especially when lifetime is taken into account.
Our recommendation is therefore lithium batteries, but AGM batteries might be more suitable for occasional use from a cost perspective.
Installation of a lithium-ion battery
Depending on how fit you are in handling batteries, we recommend ready-made solutions or at least individual components. Ready-made systems are usually easy to connect via Plug & Play. However, you can save a few euros if you do the cabling yourself or do not use a protective plug but connect the poles directly to the cable.
In the high-voltage range for motors from 15 kW upwards, the installation must necessarily be carried out by a master electrician. If possible, we rather recommend motors in the low voltage range. This also simplifies the connection of the on-board electrical system and increases safety.