Torqeedo Lithium Batteries

Torqeedo’s POWER series lithium batteries, developed with BMW, are the optimal power source for your Torqeedo Cruise Outboard or Pod Motor. They are notably lightweight, for their power capacities.

Lithium batteries are much lighter and more compact than traditional lead acid ones, meaning that for most applications they are the only viable choice for electric boat propulsion. And Torqeedo’s Power series batteries, borrowing technology from BMW’s I-Series electric cars, are right at the top of the lithium marine battery game – particularly in terms of weight.

As an example:

• 2x Torqeedo Power 48-5000 batteries (total capacity 10kWh) would weigh 73kg
• 1x Epropulsion E-Series E175 battery (total capacity 9kWh) would weigh 87kg

Factoring in the different capacities (ie 10kWh vs 9kWh) the Torqeedo battery is about 25% lighter than the Epropulsion, on a “kilos per kilowatt” basis.

Torqeedo Power batteries are rated to have 80% of their original capacity after 3000 charging cycles. Put another way, if you were to charge and discharge them every day for eight years the capacity would only have deteriorated by about 20%! Typical lead acid batteries are rated to last about 500 cycles, but only if you don’t discharge them below 50%… if you were to use 90% of their capacity (which you can do with lithium, without a problem) then the number of cycles before you noticed deterioration would be in the 10s.

As with all batteries there’s also a slight annual loss in capacity just by existing, of about 3-4% – depending on how they’re stored, at what percentage of their capacity, etc.

For most users therefore the Torqeedo battery life, in terms of charge cycles, can be said to be at least ten years. If you were using lead acid batteries for electric boat propulsion (ie at or near their limits), it’s likely you’d need to replace them every two to three years.