electric Seawind 1000 XL2

[aybabtme]

Hey there. This is sort of a report on my experience so far with a DIY conversion to electric.

• 2012 Seawind 1000 XL2
• Original: 2x Yamaha 9.9HP
• Repower: 2x ePropulsion Evo Pod 6.0
• Battery: 1p16s of CATL 280Ah LFP
• BMS: REC 16Q BMS

For a few months now I've been enjoying the electric conversion of my Seawind 1000 XL2 from 2x9.9HP yamahas to 2x6kW ePropulsion Pod 6.0 drives. The pods are currently used as glorified extra-long shaft outboards, with custom legs while I'm prototyping and testing which leg length is ideal (I have a 28in one and a 36in one!).

So far I really enjoy it. The engines are always available when I need them, require no maintenance, no nothing. If I need them, I put them down and use them. They start 100% of the time.

I use them to get in and out of harbors, and then I lift them up and sail. I got new fangled sails, and upwind, downwind lightwind sails. I use them all the time.

Still working on adding a whole lot more solar than the punny 200W I got on an arch. Design phase.

Here's a very roughly made watt-to-SOG graph I made one afternoon of going back and forth in a channel, in mild conditions (5 to 15kts of wind, upwind and downwind).




The legs on which the Pod 6.0 are attached are currently prototypes and definitely not the final product. I'm not sure yet how I'll design the ultimate leg, but for now I wanted to learn about the critical dimensions and whether deeper or shallower would be best. So far the 28in depth is better. More data needed for conclusive results. The installation looks like:






The controller is very clean, and it's much easier to maneuver with precision using this than the old crappy cables-and-slow-to-respond-gasoline-engine setup:

[ChrisJHC]

Nice!

It would be good if you could include an estimate of cost as well.

[aybabtme]

About 22k$, but this includes everything:

- 2x3000 Victron multiplus II
- Battery, BMS,
- Cerbo GX
- Cabling, bus bars, breakers
- Controller, display, drive units
- Electric tilt and trim
- Shipping for everything

But doesn't include my labor.

[CatLove]

Interesting project. A couple of questions :
-How did you implement the electric tilt and trim ?
- how well does regen work?
- is the ePropulsion system able to integrate with NMEA2k , or any other method to talk to an MFD ?
- what sort of range or better yet, what discharge rate do you get at various power levels? Do you have to rely on ePropulsion's estimates and how accurate are they compared with the Victron current monitoring ?


I am very interested in something similar for my catamaran. I have 2 3kW outboards and am looking into adding more solar, converting to LiFePO etc . I am working to develop an interface to integrate with my B&G MFD's

[aybabtme]

For tilt and trim, I used two CMC PT-35 Tilt and Trim.

Regen is still a work in progress. ePropulsion only enables it on their proprietary batteries, but you can get the binary format if you sign an NDA, apparently. I'm in the process of reverse engineering their binary format to avoid signing that NDA. https://github.com/aybabtme/eprop-re

It doesn't integrate with N2K which is another reason I want to reverse engineer their protocol. Ultimately I want all this stuff to bridge over each other, and publish to a timeseries database so I can make Grafana dashboards.

The discharge rate observed at the battery is pretty much the same as that measured by the outboards. At 12,000W it was pulling about 250A. I don't recall any worthwhile difference between the BMS shunt measurements and the outboards. There was some voltage drop but nothing that would change my calculations significantly.

I'm not sure about range yet, but I ran 12,000W for a bit more than an hour while tied up, which is what I wanted (1h autonomy at full power). Happy that it worked as designed.

[toolbar]

Following with lots of interest. I have two Yammies 9.9 in my new (old) boat. I was planning to replace them with a system just like yours before I realized, that they were just 2 years old.

I will probably use them for a few more years until they start having problems.

I hope that you manage to reengineer the wire protocol. Especially with a light multihull that sails well in light winds the regen-feature looks like a great feature on paper.

Paul

[toolbar]

@aybabtme: just for reference - do you remember your old cruising and max-throttle speeds with the two old 9.9s?

[smj]

Originally Posted by toolbar

Following with lots of interest. I have two Yammies 9.9 in my new (old) boat. I was planning to replace them with a system just like yours before I realized, that they were just 2 years old.



I will probably use them for a few more years until they start having problems.



I hope that you manage to reengineer the wire protocol. Especially with a light multihull that sails well in light winds the regen-feature looks like a great feature on paper.



Paul

A boat like yours sold about a year ago with I believe twin Oceanvolt electric motors installed. From what I hear this didn’t work out for the new owner and he built sleds and installed twin Yamaha 9.9’s to take the place of the electric.

[CatLove]

Originally Posted by smj

A boat like yours sold about a year ago with I believe twin Oceanvolt electric motors installed. From what I hear this didn’t work out for the new owner and he built sleds and installed twin Yamaha 9.9’s to take the place of the electric.

TRT1200 is a lightweight performance boat. Oceanvolt motors use saildrives and need large capacity batteries and the whole setup tends to be more like having inboard diesels , which may not be a best fit for a cat like the TRT.



I'm installing the 2 electric outboards but am keeping the central pod with the 30hp Yamaha . Sort of a poor man's hybrid . A few kW of electric is ok for benign conditions but for those rare occasions when things go bad or if extended motoring is needed the 30hp is a must that's why it stays.


Some reasons I chose outboards rather than pods - I don't want to haul out for pod repairs/maintenance. Pulling up an outboard is so much easier. If I end up disliking these outboards I can always replace them with other types, be it electric or gas. No holes in the boat to deal with and they don't take any room inside either.

[CatLove]

Originally Posted by aybabtme

For tilt and trim, I used two CMC PT-35 Tilt and Trim.

Regen is still a work in progress. ePropulsion only enables it on their proprietary batteries, but you can get the binary format if you sign an NDA, apparently. I'm in the process of reverse engineering their binary format to avoid signing that NDA. https://github.com/aybabtme/eprop-re

It doesn't integrate with N2K which is another reason I want to reverse engineer their protocol. Ultimately I want all this stuff to bridge over each other, and publish to a timeseries database so I can make Grafana dashboards.

The discharge rate observed at the battery is pretty much the same as that measured by the outboards. At 12,000W it was pulling about 250A. I don't recall any worthwhile difference between the BMS shunt measurements and the outboards. There was some voltage drop but nothing that would change my calculations significantly.

I'm not sure about range yet, but I ran 12,000W for a bit more than an hour while tied up, which is what I wanted (1h autonomy at full power). Happy that it worked as designed.

Reverse engineering the protocol in order to enable regen is the highest importance. Reverse engineering the protocol to integrate with N2k is great but without regen is worthless. Grafana I couldn't care less, there are many options to display data including history so inventing a better mousetrap is low on my list.


However I suspect enabling regen is not just a matter of issuing some protocol commands to the motor. Motor and battery must talk constantly in order to decide charging parameters, which are battery dependent, charging current and voltage changes over time with battery SOC, temp , motor RPM and temp etc.

It may be that this is a distributed system where the motor is not a complete and standalone charger and some charger functionality is integrated with the Epropulsion battery . In that case simply enabling regen in the motor wouldn't be able to charge a regular LiFePO battery .

It may very well happen that there has to be some additional hardware between motor and non Epropulsion battery to do the charging .

[aybabtme]

Torqeedo allows charging third party batteries and I hear that ePropulsion too from the flip of a boolean flag, if using the right messages. In any case my BMS talks over CAN and shares allowed currents and a pleatora of stuff, and the electric drives over UART. Whatever parameters the original battery shares, I'm fairly confident I can emulate, translate, or hard code. I'm not anticipating this to be as hard as you portray it to be, once the binary protocol is cracked.

There isn't additional hardware, I disassembled the things and traced the cables, connectors, traces and chips involved on both sides. The control is programmed in the throttle display, which is part of the UART network. The outboard is the master node, the throttle and battery are slaves.

[smj]

Originally Posted by CatLove

TRT1200 is a lightweight performance boat. Oceanvolt motors use saildrives and need large capacity batteries and the whole setup tends to be more like having inboard diesels , which may not be a best fit for a cat like the TRT.



I'm installing the 2 electric outboards but am keeping the central pod with the 30hp Yamaha . Sort of a poor man's hybrid . A few kW of electric is ok for benign conditions but for those rare occasions when things go bad or if extended motoring is needed the 30hp is a must that's why it stays.


Some reasons I chose outboards rather than pods - I don't want to haul out for pod repairs/maintenance. Pulling up an outboard is so much easier. If I end up disliking these outboards I can always replace them with other types, be it electric or gas. No holes in the boat to deal with and they don't take any room inside either.

We currently own a TRT1200 GT and have owned 2 Seawind 1000’s in the past, and I pretty much agree with all you say.
There have been a couple of TRT’s that have been fitted with diesels, not my cup of tea as they ad weight, drag, unnecessary holes and metal under the waterline and in my opinion are harder to maintain. But some people insist on them.
Your setup is interesting. What’s the weight gain from the electric motors and necessary items needed on your setup? I can see the electric motors being used to motor from and returning to a dock with shoreside recharging capabilities, but unsure of the added weight if it includes a massive battery bank and acres of solar.
There’s a Seawind 1000 in S Florida that I believe has 2 electric motors connected to a straight shaft and standard prop, and also 2 electric outboards that sit in the original pods.

[toolbar]

Ignoring range/capacity(!), the weight difference in weight does not seem that big.

2* Yamaha 9.9HT 90kg
2* Mechanical Throttle Control, Push/Pull cables 8kg
2* empty plastic tanks, gas tubes, 8kg
2* a bit of fuel 10kg
2* starter batteries 30kg
-> 143kg
(throw in a watt+sea generater at 9kg to get the hoped-for regen...)


2* Epropulston Evo 6, 72kg
1* 48v 280ah battery bank, 90kg
1* cables+electric control, 2kg
1* battery cable 5kg
-> 168kg

(only the major weight were researched, others are guesstimates)


I know about the TRT that reverted to burning fossils. But I wonder what the problem was.

Paul

[smj]

Originally Posted by toolbar

Ignoring range/capacity(!), the weight difference in weight does not seem that big.



2* Yamaha 9.9HT 90kg

2* Mechanical Throttle Control, Push/Pull cables 8kg

2* empty plastic tanks, gas tubes, 8kg

2* a bit of fuel 10kg

2* starter batteries 30kg

-> 143kg

(throw in a watt+sea generater at 9kg to get the hoped-for regen...)





2* Epropulston Evo 6, 72kg

1* 48v 280ah battery bank, 90kg

1* cables+electric control, 2kg

1* battery cable 5kg

-> 168kg



(only the major weight were researched, others are guesstimates)





I know about the TRT that reverted to burning fossils. But I wonder what the problem was.



Paul

Not sure what the problem was with the electric drives, he just said they were a total joke. I’ve asked and will see if I get a reply.
You asked about speed with the 2 Yamaha 9.9’s. We cruise at low to mid 6’s burning about 1 gallon per hour. Top speed probably upper 7’s. There’s a TRT in the US that says he can get 15 kts full power out of a single Honda 50hp, but I wonder what the fuel burn is…..

[CatLove]

Originally Posted by aybabtme

Torqeedo allows charging third party batteries and I hear that ePropulsion too from the flip of a boolean flag, if using the right messages. In any case my BMS talks over CAN and shares allowed currents and a pleatora of stuff, and the electric drives over UART. Whatever parameters the original battery shares, I'm fairly confident I can emulate, translate, or hard code. I'm not anticipating this to be as hard as you portray it to be, once the binary protocol is cracked.

There isn't additional hardware, I disassembled the things and traced the cables, connectors, traces and chips involved on both sides. The control is programmed in the throttle display, which is part of the UART network. The outboard is the master node, the throttle and battery are slaves.

This is very interesting. I don't have an Epropulsion battery to see what's inside .

Do you have any pictures ? The only images I could find online were on the FCC website for the throttle controls.

It's totally unclear how Epropulsion got away with only submitting the throttle control when the other wireless components have to transmit back so they should have been submitted too.


The main question is what part of the system is taking care of the battery charge profile. Is the motor doing a constant current followed by constant voltage regen charging?

Given the variable speed thru the water, it would be difficult to maintain a constant current or voltage unless there is a buck or boost (or buck/boost) switcher inside the motor to act as charger.

The battery BMS is only able to switch off when parameters are exceeded, that's why I was saying that either the motor or battery must have an extra module that acts as a DC-DC charger. A normal BMS is not acting as a constant current regulator.