Torqeedo on a Wharram 31'

[PanuV]

The 9.9 hp 2-stroke on our Wharram Tiki 31 is dying. There would be a practically new Torqeedo 1103 cs (1100 W) for sale in my hometown. I like the idea of electric propulsion, but I don't know anything about it. Any experience?

Someone said that two 1000W electric engines would easily move a heavy displacement monohull at steady 4 kn. Therefore a light and very narrow Tiki (3000 lbs?) wouldn't be too much for one engine.

Our needs would be:
- getting in and out of a marina also in windy conditions (this the main priority)
- motoring 2-10 nm when having a schedule and no wind
- crossing busy shipping lanes also without wind
- archipelago sailing, weekend sailing, 1-2 day offshore passages (no need for motoring on passages)
- we dont have tides nor currents (lake & Baltic Sea)

I'm a bit sceptic, but I'd be interested to learn more.

[boatman61]

Do you have recharging facilities on board or would you carry spare batteries.

[PanuV]

So far we don't have recharging facilities, but we are going to install solar panels.

So far (a new boat) we've just recharged our only battery (for lights, gps, charging phones etc.) when required. Going electric would have to change that.

[StuM]

1100W is only about 1.5HP.
How fast does your Wharram go at idle revs on your 9.9 Yamaha
That's about what you would get from the Torquedo, especially when it is weighed down with the necessary batteries and solar panels.


(Having spent a month cruising on a Tiki 31 with a 9.9 outboard, I'd expect around 2.5 knots in reasonable conditions with 1100W. In heavy weather, you will not be going anywhere.)


How big a battery bank and how many Watts of solar are you going to put on the Tiki? To go your anticipated 10 miles, you are going to need around 4000WH of storage and you need enough solar to replace that.

[PanuV]

StuM, your questions are pretty much answers to mine, regarding the solar and the battery bank - as I said, I know nothing about the issue.

2.5 kn in reasonable conditions sounds like something I anticipated. That would be enough for entering marina, but I might find it frustrating when motoring a distance. It is something I'd like to avoid, but it is not always possible. The skipper is retired and doesn't motor, I have to sail to schedule sometimes.

I don't think we would use any engine in heavy weather. The 9.9 hp outboard is quite useless when it is very windy or the waves are steep.

[PanuV]

Actually the skipper/builder of the boat might be happy with just a sculling oar.

However our berth is located in a cove that is closed by a power line with clearance only near the shores. I wouldn't want to scull into the cove under the power line in bad weather.

[Redreuben]

Forget it. Unless you have money to burn.
In which case you wouldn’t be sailing a Wharram.
Electric drive is ideologically noble but at the coal face it doesn’t have the goods.
Maybe if your sailing is marina based but out in the wild ?
Nuh.

[deepthought]

We tried torgeedo on a 28ft cat before 2x of there 4kw models was a nightmere both dealing with torgeedo and the drives them self. Almost lost the boat.



The photos I attached are from new engines.

[Franziska]

Might be worth considering a conversion of the 9.9 by removing the power head and replacing it with an electric motor.

There are a few youtube folks who have done this.

If one of our 9.9 would die we would convert it and keep the other one.

Use electric whenever possible and run the petrol engine when necessary or over longer distance.

Would obviously necessitate solar charging and if possible LiFePo4 cells.
We built ours from cheap(ish) Chinese cells and are happy so far.
On a cat you have plenty of space for solar.
We have 1200w on the arch but could add the same again as a hard bimini and another time on the roof. So 3600w at max on a 35ft cat.
Battery size seems the main issue. I'd not anticipate to run more than a full hour electrically.

[AJ_n_Audrey]

Originally Posted by StuM

1100W is only about 1.5HP.
How fast does your Wharram go at idle revs on your 9.9 Yamaha
That's about what you would get from the Torquedo, especially when it is weighed down with the necessary batteries and solar panels.


(Having spent a month cruising on a Tiki 31 with a 9.9 outboard, I'd expect around 2.5 knots in reasonable conditions with 1100W. In heavy weather, you will not be going anywhere.)


How big a battery bank and how many Watts of solar are you going to put on the Tiki? To go your anticipated 10 miles, you are going to need around 4000WH of storage and you need enough solar to replace that.

I have a Torqeedo 1100, and I believe it generates more like 3HP. The concern I would have is if you have adverse wind or current, is 3HP enough? Also, the life of the battery is radically different depending on how hard you run it; going from memory, I think you exhaust the battery in 30 minutes at full throttle. You should read the spec sheets. I use it for my dinghy for most runs to shore, because it has more than enough power for that and it's easy to get mounted on the RIB because it can be disassembled, but I also carry a 9.9HP on the mother ship for longer runs / exploration.

[ItDepends]

There is just no way around the fact that 1100 Watts is equal to 1.5HP. That’s basic engineering and physics.

Would you feel silly asking if you should replace your 9.9HP gas outboard with a 1.5HP one??? Because that’s the actual question you are asking. I think you already know the answer to that.

[Franziska]

9.9Hp are about 7.8kw so yes that's much more than the Torqueedo in question...

[MikeHoncho]

sounds like you are trying to justify fitting a square peg into a round hole.

[purvisgs]

If you have shore power to plug into at the dock & just need to get in and out of the harbor to put the sails up, a torqueedo is probably an option. Perhaps even a good option. Not that torqueedo though.

Around ~780 watts = 1hp, so that model is like 1.5hp. Comparing electric to gas is not exact, so yes a smaller "hp" electric will probably do the job of a 'slightly' bigger gas engine in some cases, but would you put a 2hp honda on that boat? NO. Yes it could push the boat around, but what about cross winds etc?

I don't know much about the full Torqueedo model/lineup but I believe 1103 cs (s for short shaft) is a short shaft, travel model-(small detachable built-in battery I believe)- basically a dinghy motor. So I think for going torqueedo in a 30ft cat you need to step up to a bigger model, long shaft, the biggest you can find ($$$$) and then expect say upto 3-3.5 knots in flat water. With quite limited range, depending on your battery bank and charging capabilities. And no ability to motor into a chop or swell.

Yes you can (and would need to) add a larger battery pack - qty3-4 lifepo "car battery sized" setup would be a starting point- enough minimal range, or 4-6 lead acid, perhaps. There goes the weight benefit, so unless you need a good sized house bank for other reasons, & additionally want to add something like 1kw solar to even start to make a dent charging those batteries when not at the dock, -it's a downward spiral of adding more weight and cash.

Learn to work on your 9.9 (75% of the time a 'dying' outboard just needs basic work like carb cleaned) or track down a used older yamaha 9.9 high thrust 4-stroke with ex long shaft. There is no better option for your boat- period.

If buying new the 9.8 tohatsu or Suzuki could be considered as well (lightweight & sweet spot in price to quality). Other options to look out for if you're shopping used would be Tohatsu 8hp and Tohatsu 9.8 2-stroke, extra long shaft, or Yamaha 8hp 2 or 4 stroke.. Those aren't as appropriate for a heavy cat as the high thrust Yamaha 9.9 though.

[StuM]

Originally Posted by AJ_n_Audrey

I have a Torqeedo 1100, and I believe it generates more like 3HP.

Someone else who believes the EP manufacturers fairytales?
It's simple physics.
I HP = 745.7 Watts.

1100 Watts = 1.475 HP.

Don't fall for their claims of "equivalent HP". It's pure BS based on very dubious assumptions such as equating static bollard pull and torque at very low revs for a gas engine with real world performance.

Discussed at length in this thread:
https://www.cruisersforum.com/forums...ml#post3460542