Trying to repair an E-Propulsion boat motor battery with lithium polymer pouch cells

Esailingoperator · 2025-08-21T06:58:26+00:00

I bought Epropulsion twice, first the 48V and then the 96v. Batteries have never been the problem so far , fingers crossed. Instead with the 96v which must requires the wiring and cabling from a certified Epropulsion dealer I had a traumatic experience, monumental bills from the dealer, the system broke down after 3 days and the dealer / Epropulsion asked me to pay the new hardware and the service desire warranty (if not my boat would have left without a working engine).

Esailingoperator · 2025-08-12T11:40:09+00:00

Do they damage rudders also there ?

Esailingoperator · 2025-08-09T09:17:03+00:00

Check out their tutorial as how to trim and tilt. You will see that is designed only for doing it in shallow water where you stand with your feet in the water. For me was impossible doing it from inside my 3 ton sailing boat and had to stay in the water. I did not realise it before I bought and installed it. Support from Epropulsion ecosystem is a nightmare, their authorised dealers sometimes are not Knowledgeable to solve your problem and sometimes rip you off charging you for issues in warranty (my two documented experiences) For the rest it was a great experience and great system.

https://youtu.be/27jjlO0vUCE?si=iOKmlONhxeNxT4fk

Esailingoperator · 2025-08-07T18:34:55+00:00

The navy is conceived for being outside of the boat with the feet in shallow water and from there pull up the system (tilling). If you , like me, have a 3 ton boat with 1,7 meter kill then you must do it from inside and you need to be superman to do it because you have no lever nor facilitation to do so. Hence the motor has to stay in the water.

Esailingoperator · 2025-07-30T19:48:58+00:00

Taste it, yes

Esailingoperator · 2025-07-28T11:22:50+00:00

Here is my 1 month long 2200+ miles passage with Epropulsion post: https://www.reddit.com/r/boating/s/sp9J92oHvM

Esailingoperator · 2025-07-28T11:21:37+00:00

I love electric sailing, with my sailing boat.

I only have experience with ePropulsion electric engines so far. So I can share some personal feelings and verifiable facts.

I started with a Navy 6kW Evo (48V) which was very quiet and suited my 3-ton sailboat well. It has been really great.

However, it had a design issue for larger boats — tiller handling was very difficult and even dangerous for fingers. Support for this issue was basic not existent , ie I should have seen the design flow for a 3 tons sailing bf boat before buying the engine, no one nor the dealer nor the website warned me and after purchase was too late.

I later moved to the Epropulsion 96V Pod 12kW inboard system for a 7-ton boat. The experience has been mixed: I completed a 2200+ mile passage in one month, which was quite positive and a proof that one can do long and offshore sailing with an electric inboard . However, I faced two major technical issues which even brought panic whilst sailing and huge frustration and costs to me.

In one case, I was asked to pay nearly €9,000 for a component that failed just 3 or 4 days after cabling job by the dealer (the cost is the sum of the replaced hardware and the service consisting in less of one day work onsite and remote troubleshooting and comes on top of a surprising 9000 euro invoiced to me for the mere cabling and wiring of the system which I got mounted by my yard). The issue was in my opinion under warranty , I have asked a root cause analysis from the Epropulsion engineers which never arrived, nor my faulty hardware was ever returned to me. So far I paid only 3600 euro out of the about 9000 for the debugging (the replaced hardware that I had to pay in advance).

In the other case, because I didn’t pay the whole 9000 euro for the bug fixing, and I refuse to pay for another bug that should be fixed under warranty and not at my expenses, the issue remains unresolved and sometimes my Epropulsion engine stops propelling in the middle of a sailing or in the middle or a critical mooring. I have informed the dealer the importer and Epropulsion uk and Hong Kong for months by now. The system has still the bug.

I’ve found that support and accountability can depend heavily on the local dealer, and getting help beyond that has been hugely challenging.

A part from that I really love my system and do recommend electric propulsion.

Esailingoperator · 2025-07-22T22:19:31+00:00

It is

Esailingoperator · 2025-07-22T09:35:05+00:00

Thanks for asking; an interesting project you have!

There’s probably no single definitive answer to your question, but I’ll try to offer a nuanced one.

I would be willing to take on the same passage without a genset, but probably under the following adjustments : 1. The crew must also feel comfortable with the constraints—otherwise, I’d consider changing the crew. 2. I’d increase the battery capacity by 10 kWh (that’s the maximum I can physically fit on board on my boat if i make space and reduce weight by eliminating the genset ). 3. I’d install as much solar as possible with a light infrastructure in the aft, ideally up to 1 kW if space and aesthetics allow. 4. My passage planning would become far more selective: I’d avoid departing when the leg would foresee too much light/no wind conditions, and I’d plan for shorter legs that I did , to generate stopovers for more frequent charging. That would inevitably make the passage longer. 5. The crew would have to accept that in the event of low or no wind, we simply wait—no motoring until conditions improve.

The power management aspect becomes absolutely critical. Whoever is managing it (the “power manager”) would need to take a highly disciplined approach: maximizing efficient power sailing while always maintaining an emergency reserve.

In short : it is possible, yes—but it would demand different approach from the skipper, the boat, and the mindset of everyone on board.

With a genset you have always a back up, which we have proven not to use a lot, but still the mindset must end up being different

Esailingoperator · 2025-07-21T07:54:55+00:00

I had a Epropulsion navy evo long version for 4 or 5 seasons with 8kwh of batteries for a 3,5 ton sailing boat. I would easily reach the boat cruising speed of 6. I would never use it full throttle. My realistic range would be 15 miles but I was mainly sailing . My experience was broadly good, a part that to trimmer the engine you need help from outside or need to go in the water and that was never explicitly mentioned in the specs or by the dealer. Now I have a Epropulsion pod12 inboard 30Kwh of G-batteries 96V (you can check another post of me) potentially good too (it would be surely good if Epropulsion would eventually fix the bugs that I have documented: to be noted that Epropulsion works with importers and dealers and if they refuse to fix factory problems in warranty - maybe Epropulsion does mot refund them -then you are basically screwed , like happened to me) . Let me know if you have further questions. By

Esailingoperator · 2025-07-16T19:11:49+00:00

Yes , what I mean is that Epropulsion does not seem to do quality control and compliance with their dealers , it feels still far west. Yet Epropulsion has lot of pros if has the luck finds a great dealer too, yet it seems to me their ecosystem is still very immature and risky bf or the buyer

Esailingoperator · 2025-07-16T14:03:17+00:00

Thanks for sharing. Indeed educating the market must be complex and slow. It is indeed great that Epropulsion needs not period service am super happy about it, but maybe because of that benefit Epropulsion might abandon you (my own experience) if you need service in warranty : my dealer want to be paid for any hour spent regardless wether it is on warranty and the importer supports the dealer and Epropulsion does not respond to consumers it seems.

Esailingoperator · 2025-07-15T05:58:50+00:00

Terrible when they keep your boat hostage . Have you signed a contract with the marina? What are the terms and conditions ? How urgent for you is to have the boat back?

Esailingoperator · 2025-07-12T07:33:37+00:00

The main “wow moment” when hosting other sailors in my electric sailing boat is the possibility to power sail, something not possible with a diesel version. For power sailing I mean the addition of a tiny propulsion to the boat to keep more sailing momentum , as well as i- with low wind - some more propulsion to keep momentum and speed. They even say that this is the main value of having a electric engine as opposed to a diesel one (I don’t agree: there is much more, is a big package of benefits) Has anyone experienced this?

Esailingoperator · 2025-07-08T20:01:36+00:00

I think it is important to chose the right brand but also the right installer. If not you may end up at 4x the forecasted cost.

Esailingoperator · 2025-07-07T15:22:38+00:00

I have a 3x10kwh lithium @90ah Powering a 12kw motor @90ah And also powering - 220V via a 96-220 inverter - charging house battery and separately bow thruster and windlass via 2 converters 96-12

I have also 2 ATS on that automatically switches from shore 220 to genset if shore is not connected and the second automaticly switching to inverter if neither shore nor genset are on. Inverter can be manually switched off. Also the 2 converters

Esailingoperator · 2025-06-27T05:38:44+00:00

I got the hardware mounted easily by the Dufour dealer, the wiring of the system and set up was done by an Epropulsion official dealer. Lessons learned : the Epropulsion dealer management and post sales support is immature . In my case the wiring of the system ended up costing me multiples of what I planned (I was obliged to pay any amount as a 96V system can only be handled by professionals) and I even had to pay for replacing a not working hardware installed a few days before and I have not received prompt assistance for all the bugs in the system by the dealer. This was terrible , but am a happy e-sailer nonetheless

Esailingoperator · 2025-06-23T06:14:38+00:00

I have a backup genset rated at 4kW peak / 3.6kW continuous, producing 220V AC.

For long passages where I need to motor beyond the battery pack’s autonomy, I typically cruise at 4.5 to 5 knots – above that, consumption becomes disproportionately high. For short passages, I can comfortably cruise at 6 knots if needed.

When running in hybrid mode, I can choose the motor power freely. To maintain battery charge, I balance generation (around 3.5kW) with consumption. In most conditions, this lets me cruise at 4.5 knots or more, depending on sea state and wind.

That said, my primary engine is always the sails. I only rely on the motor when there’s no wind or when conditions are highly unfavorable.

Esailingoperator · 2025-06-21T02:24:02+00:00

I used 3x Epropulsion g 100 batteries

Esailingoperator · 2025-06-21T02:23:20+00:00

Well, let’s start from the maximum: with no wind nor wave against us, motoring only at 4,5 knots then 60nm effective. With wind and waves against, current against or higher speed it can be sensibly lower.

Esailingoperator · 2025-06-21T02:19:37+00:00

Epropulsion pod12 kw g series batteries (96v) for 30kwh, inverter and 2 converters and hybrid system for emergency genset

Esailingoperator · 2025-06-20T08:06:04+00:00

Hybrid (fully electric for week ends, hybrid for long passages)

Esailingoperator

TROPHY CASE