I'll try to answer a couple of the responses / questions that were generated:
Thanks for the pointer to the fine guys on the list and at Electric Yacht. I bent their collective ears quite a bit, and really appreciate the patience the had with me. In the end, I just wasn't ready to "make the jump" to replace an existing (and still running) engine. That had a LOT to do with my personal decision to go with an electric outboard.
The COST involved for the outboard installation:
* The Torqeedo motor runs about $3850 + tax and shipping. I ordered mine from West Marine.
* I spent about $300 on deep cycle marine batteries to get 4x12V lead acid batteries. This is about the CHEAPEST you can go. It's also probably the shortest range you can get. On relatively flat water, I can easily get in and out of the slip, and cruise around for an hour or so.
* I spent ~$100 on a inexpensive 48V charger. I could have spent a LOT more, and gotten a much better unit. For my use, it's fine to put a trickle charger on the bank and let it charge up from shore power while I'm away from the boat. Again, your mileage and needs may vary.
* I spent ~$100 on a medium duty outboard motor bracket that I bolted to the stern of the boat.
I had ORIGINALLY spent a LOT of $$ on the West Marine electric operated engine lift bracket. It was VERY heavy duty (and heavy, and large). Unfortunately, since my swim ladder is already in the MIDDLE of the boat, by the time I mounted the electric bracket on the side - it was so wide that I couldn't get the motor deep enough in the water. I had to go with the cheap, MANUAL (traditional classic) outboard bracket to get a bracket that was narrow enough that I could mount it low enough on the transom to get the motor deep enough in the water.
If I had it all to do over again, I would STRONGLY consider going with the PARSUN electric outboard. It's about the same price, and about the same HP. It is a LOT heavier (~78 pounds??? vs. less than 40 pounds). The big advantage of the Parsun is that it has electric tilt and trim. It's a royal pain in the tail to have to hang over the back end of a Catalina 30 to raise and drop the outboard. On a smaller boat, it's much less annoying. The Catalina 30 has a LOT of freeboard - so dealing with an outboard is cumbersome.
If I went with the Parsun, I would need a much sturdier (probably custom made) outboard bracket to allow me to bolt high, get the motor low, and support the weight. And I would then be depending on the kick-up angle of the motor to get it clear of the water (which it should).
The only other thing I didn't like about the Parsun is that it has an internal water pump. I was concerned that a water pump (for cooling) would be another source for possible future failure. The Torqeedo avoids this problem by putting the motor itself IN the water - so you're using the lake / bay / ocean to directly cool the motor. That was probably the primary compelling factor. Other than that, I couldn't tell much difference from the literature to compel me to get one vs. the other.
Also note that for my experiment, I didn't run the motor over 1000W for very long. That was because with MY system (of cheap batteries), running at 2000W+ caused the battery voltage to drop fairly quickly. To run at 2000W or even 4000W, you would need something like the Lithium battery pack, or at least golf cart batteries to support that amount of power for an extended period of time.
It would be interesting to test with my boat for at least 5 min. runs to see what my boat speed goes to in calm water with varying amounts of power. It would be a useful data point to know if 4000W would get me to 6mph.
From: Carter Quillen <twowheelinguy@yahoo.com>
To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
Sent: Thursday, February 7, 2013 10:44 AM
Subject: Re: [Electric Boats] Re: Torqeedo Electric Outboard on a Catalina 30
Graham,
Your vessel's weight will primarily effect how fast you accellerate and have little bearing on your top speed. It's the hydrodynamic drag of your hull(s) that will ultimately determine your top end velocity and even a 10% increase in mass shouldn't change that very much. I wouldn't worry about using a little heavier battery if you want to save a few bucks. Sounds to me like what you're doing should work adequately but I also wouldn't make too many extrapolations by comparing weight and horsepower with a Catalina 30.
Just hazarding a wild @$$ guess I'd say you'll be lucky to get about 4 mph in calm water with 1500Watts on each hull but with two 4 hp torqueedos you might see a little over 5 mph at full trottle if your hulls are clean. It will be interesting to see what you do get and I hope you'll share it with everyone when you get it set up.
Carter
From: Graham Meise <gmeise@gmail.com>
To: electricboats@yahoogroups.com
Sent: Tuesday, February 5, 2013 12:00 PM
Subject: [Electric Boats] Re: Torqeedo Electric Outboard on a Catalina 30
To: electricboats@yahoogroups.com
Sent: Tuesday, February 5, 2013 12:00 PM
Subject: [Electric Boats] Re: Torqeedo Electric Outboard on a Catalina 30
In reply to John, thanks for the info on your Catalina 30 and the Torqeedo 4.0. This is all very positive which tells me my future plan might just work.
The plan is to mount two Torqeedo 4.0's onto a Gemini 34 catamaran. I would be removing the center drive 27 HP motor and it;s associated weight. Using two electric motors would mean doubling up on the batteries. I need to keep the weight down and would have to use the more expensive lithium batteries. This will hopefully keep my all up weight at about 9500 pounds.
My guess is your boats all up weight is about 11500 pounds. If you are able to maintain 3 mph using 1000 watts, I might be able to maintain 5 or 6 mph using 1000-1500 watts per side.
Graham
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