T-Pain Is On A Boat: Re: [Electric Boats] Electric Risør 27

Thanks for your email Carter!

I appreciate your recommendations! I have also considered belt drive. But what about direct cogwheel drive? Maybe the most easy way? And I really have to reconsider using the parts from the Think. A 48V system with lead-batteries would probably be easier. But I do expect such a solution to more expensive than my $1000 donor car.

There is a local retailer of the HPEVS system (http://hpevs.com/) offering the AC 9 motor + controller (48V, 18kW) for about 3500 dollars. I believe the HPEVS also work with regenrative breaking - so I can use the diesel engine as a generator.

I find batteries expensive too: even chap lead acid costs at least $200/kWh - and I need at least 10kWh.

But I will do some more investigating - and maybe I could sell my Think car and make some money...

Do you have some links for solar panels at 1 dollar/W that you mentioned?

The link for your blog didnt work, strange... But I found your Arc-site: nice project;-) How many solar watts do the panels produce in the sun? Are they 1m2 panles? And how is the power demand when driving at "cruise" -speed?

I dont understand why I would like a clutch. Why not just let the electric motor turn togheter when the diesel engine is turning? And if your motor system allows it you might take the advantage of regeneration to charge your batteries...(?)

Best regards

Bendik

2014-06-17 20:46 GMT+02:00 Carter Quillen twowheelinguy@yahoo.com [electricboats] <electricboats@yahoogroups.com>:

Bendik,

I did something very similar with my boat to what you're proposing and it works pretty good. Here is a link to a picture of my driveline, www.shipofimagination.com/uploads/3/2/2/6/3226311/7908036_orig.jpg

View on www.shipofimaginati...

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The chain was a lot easier to install and less expensive but I heartily recommend a belt drive if you can work it out. Some kind of clutch would be nice too but I haven't found anything suitable yet and have to remove the chain to go back to diesel and put it back on for electric. Fortunately I almost exclusively run in electric mode and only use the diesel for emergencies, night operations, or if I'm in a hurry and the weather is bad so I don't have to switch it very often.

You can see my solar panel rig at The Flap Tracker

The Flap Tracker
The Sun Canopy Position (Panels are flat for max shade and clearance on deck)

View on shipofimagination.com

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My advice would be to stick with a straight 48V DC system and lead acid batteries, either FLA or AGM. There is plenty of hardware to choose from off the shelf that will get the job done at good pricing and 48V offers some distinct safety advantages There is a raging debate about the possible economic superiority of LiIon battery chemistry over the long haul and no question about its superior performance but it's a lot bigger investment up front. I don't think anyone is doing much with NiCads.

Good hard framed, glass glazed, monocrystaline solar with a nominal "module" efficiency of about 15% can be had for less than $1/Watt and are a very good way to go. If you can afford the new semiflexible panels for a little over $2/Watt they offer the advantage of much lighter weight and slightly higher efficiency but cost twice as much, have a much shorter warrantee and probably won't last as many years. However that remains to be seen but the hard framed panels have proven themselves for many years in the marine enviroment.

There's a lot more detail on how we built the Arc in the archives of our blog at http://www.archemediesproject.blogspot.com/. Hope you can find some inspiration there.

Capt. Carter
www.shipofimagination.com

On Tuesday, June 17, 2014 10:57 AM, "Bendik Vignes bendik.vignes@yahoo.com [electricboats]" <electricboats@yahoogroups.com> wrote:

Hi!

I live in Arendal, Norway, and I am new to this group. I dont have experience with these yahoo groups so sorry if I act a bit clumsy.

I am working on a electric propulsion boat project:
It is a 27 feet "yacht" (Risør 27) from the early seventies. Displacement hull. 3500kg
Now it has a 1964 Mercedes OM636 diesel engine. Still works OK.
I bought the boat last summer and rather quickly I started to think about conversion to electric/hybrid.

Since this is a very low budget project am looking for cheap and smart solutions...

As a "donor" a bought a 2001 Think electric car (payed about 1000 dollars). It had a charging issue, but I belive I have fixed that.
It has a 17kW Siemens 3-phase motor, Siemens simotion inverter, 19*6V, 100Ah Nicd battery (from SAFT), Actia charger, Actia BMS, a DC-DC converter and other stuff i might need... The battery, motor, controller, DC-DC are water cooled. There are quite a few people here in Norway with rather deep experience and knowledge about this car (it was made in Norway), so I believe I can get the specific technical tips about this car when I need them..

I measured the boat's "drag" by pulling it with another boat and measuring the force F with a spring weight, and the speed v with a smart phone. At 5knots, the force was 60kg*9,81N/kg, and at approx 4,5 knots the force was 40kg*9,81N/kg. Since the power P is given by P=F*v, the power at 4,5knots is about 900W. If I assume 55% propeller efficiency (is this OK?), and 80% electric to mechanical effeciency, the electric power needed is about 2kW (no wind and waves). I do expect up to ten times this power in special situations, i.e. sharp maneuvers in strong wind.

I believe it is better to leave the diesel engine: in worst case if the electric propulsion is a total failure, the boat is still usefull!

My plan is to mount a cogwheel between the diesel engine's gear box and the propeller shaft (there is not much friction when the gearbox is in neutral), and mount the electric motor just behind the diesel engine. The propeller is made for 900rpm. Gear ratio 1:3 should go fine (the motor has a max torque of 180Nm -means a current of 280A- at 1000rpm, which is about 18,8kW of power).

The motorcontroller are prepared for generative breaking, so when going by diesel power the electric motor can work as a generator and charge the batteries.

I also plan to use the batteries, BMS, charger and so on. The batteries will give me approx 5 hours driving before I need to start the diesel engine. Since Nicds should not be stored fully charged, I will need some kind of remote control to start charging some hours before a trip.

BUT, I would really like solar panels to increase the range (and possibly to replace the diesel "generator"). I guess I would need at least 500W of solar power. Here I have several difficulties:

-available space for panels (suitable for walk-on etc)
-solar charging of a relatively high voltage Nicd battery

-cost of solar panels

Since walk-on, flexible, high efficiency panels (like SolbianFlex) are really expensive, I was about to give up this solar power idea. But last night I thought that the panels dont really need to be "walk-on" - types. I could cover ordinary flexible/thin panels with a plexi glass (an a couple of cm of air gap). Now I can sit on, walk on them, drop hard things on them... But I will need cooling. This could be solved with aluminum plates and circulating water - not to difficult. Probably, there will be some more reflections due to plexiglass? Or what do you people think?

There is space for several 100*50cm panels. Maybe 7 panels.

I do believe the monocrystalline is the best option. What about these: http://www.ebay.com/itm/261501848394 ???

How is monocrystalline compered to amorphous/CIGS when the sun angel is small, and under somewhat cloudy weather? Will the voltage drop too much? I have read that the a-Si/CIGS panels works OK in shaded / partly shaded conditions. Any experinces??
Is it worth waiting a year or two for even cheaper, more robust, more effective panels??

Charging is a complicated issue I think. I cant find solar Nicd charges on the market. It might be possible to use a ordinary solar inverter and connect this to the cra*s buildt in charger. But I dont know if the charger would like such small currents that a solar array can deliver (the charger draws 10A when connected to the 230V net), and I dont know if the controllers can be reprogrammed such that the "car can drive when the charger is attached": of course I want solar power also when driving. And the charger's effeciency is probably around 75%. Togheter with the inverter*s effecincy the total charging efficiency is about 60%...

Any comments?? Better solutions??

Please tell me about similar projects that I can get som good inspiration;-)

Best regards
Bendik. Norway