Lithium-ion battery

Ewincher is equipped with a removable 25.2V Lithium-ion battery.

Its capacity is 3 000 mAh and 75.6 Wh, producing 450W of electric power.

Running time: at least 1 day of navigation for boats up to 45 feet.

Charging time: 1h30 with 12V or 220V.

Pack batterie


  • How much battery autonomy is there?
  • Do you need 1 or 2 batteries?
  • How are they recharged?
  • What technology is used?
  • What is the battery life?
  • Some maintenance advice.


EWINCHER's running time varies mainly according to its use and the size of your boat. Examples of use with 1 battery on a Dufour 405:

  • With 10 to 15 knots of wind: hoist the main sail 3 times; then tack 40 times using only the Ewincher to manoeuvre the genoa.
  • Or hoist an 85 kg crew member to the top of the mast 3 times (mast height: 14.5 m).

Removable battery: choosing between 1 or 2 batteries?

Generally, one battery is sufficient for more than one day's navigation on boats under 45 feet. So, a second battery is not necessary in this case. For larger boats, a second battery can be advisable according to its use. In case of doubt, do not hesitate to contact us.


  • Charging time: 1h30. Recharging can be done both on board (12 V DC cigarette lighter socket) from the service batteries or from the shore power supply (110-220VAC).
  • Consumption on the 12VDC service batteries for full recharging (6 Ah), which is 1.5 to 2% of the capacity of a medium battery pack (370 Ah).


  • The battery is comprised of high-quality lithium-ion cells; these are the same cells (LG brand) found in top range electric cars currently on the market.
  • Its nominal voltage is 25.2V (operates between 29.4V and 22.5V). Selecting high battery voltage is essential in order to ensure the necessary power and torque required for more difficult manoeuvres. Batteries on standard portable electric tools have a nominal voltage of 18VDC. This is not sufficient for the most demanding manoeuvres (Here is more detail about the stress test realised on drill-drivers).


There are 2 ways to anticipate your battery lifespan:

1st factor: your Li-Ion is composed of cells that will deteriorate over time, irrespective of their use. This "natural" deterioration process reduces the battery's capacity after 3 years, as a general rule. In most cases, the battery will need changing after the 4th year.

2nd factor: The lifespan test that we have conducted on Ewincher batteries show that a loss of capacity only appears after 300 full charge and discharge cycles.
Let us take the example of battery use on a 40-footer. During one day of navigation, you will consume 1/2 battery charge at the most. This means that your battery will provide at least 600 days of navigation before its capacity begins to decrease.


After a day of navigation, even if your battery is not empty, it is preferable to recharge it. In this way, it will be 100% operational for its next use, and that is the best way to preserve it.
During the wintering period, recharge your battery fully and stow it in a dry place.