TL;DR: we do believe in electric propulsion systems – but this one did not work for us (and we tried hard for 3 years)

We are not fans of diesel engines – we like to run them only when necessary to get in and out of the marina (or in and out of an anchorage.)

Fix the engine or install an electric motor?

We always prefer to keep what is already in place, unfortunately too many things were wrong on our diesel engine. At some point we had to stop the work on repairing it: the quote from the mechanics got higher than the cost of an electric drive – so we started thinking about it.

There were large flaws on the engine that required immediate action (packing gland leaking like crazy, smoke) and also mid-term plan items (corroded P-bracket, heat-exchanger and turbocharger, etc.) Also, it was clear that a lot of the regular maintenance had never been done over the past 15 years (most rubber hoses had to be checked/replaced) and there were electrical issues on the control panel.

Since the boat was not ready to sail yet, we decided to go for an electric drive installation.

Our reasons

• Skills: while I can do the basic maintenance on a diesel engine (oil change, impeller change, injectors purging, fuel system troubleshooting, etc.) I am much more confident with electric motors and electronics.
• Weight: electric motors are light (few tens of Kg) and I can handle the parts alone. Our diesel engine with its gearbox was 280+ Kg.
• Batteries: we went for a large propulsion battery bank (30 KWh) and it also became our main energy source, feeding our 240 VAC and 12 VDC circuits on demand.
• Genset: our boat came with a 4 KW diesel genset in quite good conditions (and also lacking proper maintenance). Previously, the genset was only used to have 240 VAC on board and charge the 12 VDC batteries. Now it can be used to it’s full potential and feed directly the propulsion battery bank.
• Noise: the genset is very silent – barely audible from outside, while the diesel engine makes a lot of noise and fumes and is a nightmare in the aft cabins.

30 months of installation and testing

During winter 2022, after looking at many possibilities on the market for electric propulsion, we decided on a 48 VDC system. There is a large range of appliances (chargers, inverters, solar MPPT, etc.) designed for 48 VDC, this is not the case for 96 VDC systems.

At the time, the maximum power for a 48 VDC system was 15 KW. We found the same limit across most manufacturers. In 2025, you can even find 20 kW motors (still 48 VDC).

• OceanVolt : too expensive for us, we’re not youtubers, lol. Their ServoProp is fantastic, but it really needs tons of space inside (controller with water cooling, ServoProp control box, etc.)
• Bellmarine: nice and sensible offer of electric saildrives, but it was difficult to move on with our local dealer.
• Kräutler: very nice offer too, including saildrive legs made out of bronze. Expensive too, but most importantly they would not want to sell to individuals.
• Rim Drive Technology: they were the only company selling rim driven pods (the motor and propeller are one single part that is installed below the hull, freeing space inside.) Easy installation and no need to cool the motor!

I quickly got in contact with Rim Drive Technology and we went for their new 15 kW POD that they had just released in late 2022. On March 31^st 2023, we received a big wooden box with 3 large batteries, a POD and many parts and cables!

We have been hard at work on this installation (and the rest of the boat works!) – keep in mind that we are 500 Km away from the boat and we only go there once every couple of month.

Making room!

A lot of works were needed to accommodate the new battery bank (in place of the diesel engine), and to remove auxiliary parts like the exhaust (literally sandwiched between the engine bed and the hull), etc.

We had planned to have this done by local shops, unfortunately mechanics refused to take this jobs because they only accept to do such a job if they are also contracted for the installation. Unfortunately, they refused to install an electric drive.

Once we got the engine out, we contacted a local shop to prepare the whole locker for the batteries and accessories, but the yard made it hard for us to move the boat (i.e. there was a conflict between the yard and the repair shop). So we did the works ourselves.

Inside works…

Outside works…

Installing the batteries

The battery locker (previously the engine room) got cleaned up and painted ; then supports for the batteries where added, on 3 levels. We tried to install as low as possible (but keeping a safe distance in case of water ingress) and leaving room at the top where hot air will accumulate.

Plugging in parts together

The first parts we plugged in were the batteries (the three are connected in parallel) and a VictronEnergy inverter/charger/solar charger (all in one), with a main switch and a fuse. This is now the central part of the 240 VAC system. Shore power (or the genset) goes though it, it provides stable 240 VAC for the boat (from the 240 VAC input or from the batteries).

That was when we started plugin the rest of the propulsion parts together in autumn 2023 that we realized that:

• The throttle was not in the right direction. We asked for an “anticlockwise is forward” throttle. It was indicating “reverse” on the display.
• We could not get data from one of the 3 batteries because Rim Drive had sent us one battery with a different connector. We had no cable to connect to this battery’s BMS.
• When I asked how we were supposed to connect the regen switch, I was told that Rim Drive had forgotten to install the regen firmware in the motor controller.
  • We had to return the motor controller, it’s CAN bus box, the throttle and the display
  • They returned the motor controller with an updated firmware and the same throttle. They added in the box a cable for that specific battery
  • The display got damaged during its return trip, we had to fix it by adding a new stainless steel bezel and new bolts.

I was displeased with the fact that, in 2023, some companies are still not able to update the firmware of their devices remotely, or at least make it easy for the owner to keep the devices updated.

In spring 2024, we began doing more test, before the real test in the sea:

• This is the moment all 4 CAN converters blew up. Inside each of them, the 48 VDC to 5 VDC converters burnt. The reason is still unknown. It could be a high in-rush voltage while turning the system on. It could also be defective DC/DC converters. Only a few components of the same circuit blew up, and they were all the same.
• We ran the summer tests (in the water for one hour, in the crane’s slings) without CAN bus (no display). Luckily, we could monitor the electric power directly from our VictronEnergy SmartShunt.
  • The test went well, even if I found the motor to be a bit noisy at some low rpm.

To make sure that we would not run again in this kind of situation, I included in the startup sequence of the propulsion system a dedicated VictronEnergy DC/DC converter. When we turn the key, a stable and clean 48 VDC voltage is then provided to the systems that need it.

Autumn and winter 2024 works

• Rim Drive sent us a complete and new CAN/NMEA200 setup to replace the 1st gen CAN boxes and display:
  • A new 7″ display from LxNav
  • New CAN converters boxes, directly getting power from the NMEA bus (no more DC-DC converters that can blow!)
  • A DC-DC converter (48 VDC to 12 VDC) for the NMEA bus
• We already add added a (second) dedicated DC-DC converter for the NMEA bus, so we returned their DC-DC converter.
• Rim Drive recall the POD in order to install a “saltwater improvement kit“. we add to uninstall the POD, build a box for the transport and get it shipped back to the Netherlands.
• We are still struggling to get any data out of the 3 batteries at the same time. It turns out that the LxNav display only supports 2 batteries… and that the BMS in one of the batteries is not working properly (no data).

Fast forward to spring 2025

• After a few emails with LxNav support, I am asked to upgrade the display’s firmware to get the support for 3 batteries.
• A new battery was received (with a working BMS)
  • The defective battery was send back, along with parts that were not needed:
    • the DC-DC converter (we already had 2 of them installed)
    • the 1st gen display (no longer compatible)
• The POD was received, after the installation of the “saltwater improvement kit” and some tests at Rim Drive’s facilities and was installed back in place.
• Once its firmware got updated, the LxNav now has support for 1 propulsion battery (that is the VictronEnergy SmartShunt + Digital Yacht‘s veKonvert) and the 3 batteries (that are the 3 CAN converters).
  • Unfortunately, the new LxNav firmware also expects new electrical data (new PGNs) that no NMEA device on board are able to send (not the veKonvert, and none of the CAN converter from Rim Drive Technology).
  • … so we can not configure any electric propulsion battery on the display.
  • … and without an electric propulsion battery, no electric drive can be configured.
  • All in all, the LxNav display… does not display any information from our drive and propulsion batteries.

We plugged a new Garmin TD50 display on the propulsion’s NMEA network and we finally got data visible! Although the Rim Drive’s LxNav display is still not working, we are ready for the first real tests, at sea. One of the drawbacks of this POD motor, is that it can only be run in the water: testing the propulsion setup on the dry is not possible.

First tests during summer 2025:

Our boat is launched into the sea for 15 days in July 2025. Those are the first 15 days we will spend on the boat, in the water! We quickly realize (when bumping into the pontoon) that we are not getting full power going forward, only ~10 KW. Going in reverse was fine, with the full 15 KW.

While at the dock, we checked the data from the VictronEnergy SmartShunt :

• Full reverse on the throttle, we have 15 kW of power
• Full forward on the throttle, we have only 10 kW of power – for some unknown reason.
  • While we could swap two of the phase wires in the motor controller and get full power forward, the throttle also had to be reversed. And we are not having full power in reverse.
  • Unfortunately, the throttle can not be reversed, so we had to mount it up-side down.
  • Rim Drive was not providing any significant help during that time.

After a few tests. there are only a few possible causes for this issue: a defective throttle or throttle cable, or an invalid motor controller configuration. Unfortunately, Rim Drive was not willing to able to help us to fix the system : they did not provide any technical information on their throttle and, globally, they do not want us to check the firmware and configuration on the parts we own. This is very frustrating.

We finally left the marina with 15 KW forward, ~10 KW in reverse and an upside-down throttle.

• The motor controller does indeed produce much more heat than anticipated (it easily reached 85°C). We had installed aluminum heat radiators on the back (on the thick integrated aluminium backing plate), but this is not enough. Water cooling is probably the way to go. Rim Drive confirmed in July 2025 that this specific controller requires solid heat management as it is known to heat up.

• After our first navigation, a quick dive revealed that one part of the POD drive went missing: the inlet ring. Nothing critical, it is just a plastic part that is bolted on, but a bit scary as a first sail.

• The drive is still making a periodic knocking sound while running (just like last summer), which does not feel right. We recorded a video and sent it to Rim Drive Technology.
• Going back to the crane on the last day proved to be challenging : with very little power in reverse – we slooooowly hit the pontoons once again – even knowing there was an issue and acting early.

We still managed to run a performance test in July. Weather conditions during this test:

• Sea state: flat / no current
• No wind
• Temperature around 24°C

Power at the shunt [KW]	RPM as reported by the POD [min-1]	Speed Over Ground [knots]	POD Temperature [°C]	Controller Temperature [°C]
1	600	1.5	29	24
2	800	2.2	30	24
3	900	3	32	25
4	1000	3.6	34	26
5	1100	4	36	28
6	1150	4.2	38	30
7	1200	4.4	40	32
8	1250	4.6	41	34
9	1300	4.7	44	36
10	1350	4.9	46	40
11	1450	5.1	48	43

The take away is that we did 3 knots at ~3 KW and 5 knots at ~10 KW. This is exactly what we expected/needed. This is a great relief after all the negative comments we got, like : “15 KW are not enough!” / “This is a security risk!“

We did not run the POD over 11 kW because the power delivery was unstable.

September 2025

Rim Drive Technology does not know what is causing the knocking sound inside the motor and is not providing any answer on the throttle/controller issue. The display issue is supposed to be fixed in an upcoming update of the CAN boxes. As of August 2025, Rim Drive Technology stopped responding and providing support.

We went back to the boat yard to turn the drive by hand, as requested by the support team, to discover that the the POD had seized. We let the POD soak in fresh water to dissolve any dry salt in it, but still no luck. The POD’s blades were stuck.

For a few weeks, Rim Drive was no longer responding to our emails or Whatsapp messages. We were left with a non-working propulsion system ; each component, that has been back to Rim Drive Technology at least once (i.e. most components!) was under warranty until the 30^th of September 2025. We contacted the official reseller in France to make sure that Rim Drive Technology was still in business. The reseller contacted Rim Drive Technology and eventually they got back to us and asked to send all components back to the Netherlands once again.

All components have been uninstalled (October 2025) and send back to Rim Drive Technology in the Netherlands (January 26), along with a formal request for refund: over the last 3 years Rim Drive Technology failed to provide us with a fully working propulsion system, and Rim Drive Technology failed to fix the system in many occasions.

June 2026

Rim Drive fixed some of the broken components (the POD drive and one cable) and confirmed there was two “known issues” – no information was provided. We are still not willing to get this propulsion system back as we do not trust it anymore and we lost all trust in Rim Drive Technology that let us sail with two critical known issues on their system.

We sent a second formal request for refund but Rim Drive Technology is not willing to refund and the CEO says Rim Drive tried to call us for weeks – but we never got a single notification of a call.