Chris,
I have a Catalina 22, which is probably a bit bigger than your boat, and likely heavier. I recently went through what you discussed, and can offer my observations, based on comparing the Traxxis 80 to the Torqeedo 2T:
TRAXXIS 80:
This is a MUCH less expensive solution ($529US at Cabelas.com vs. $3300 for the Torqeedo 2T at WestMarine.com)
Traxxis web page: http://www.cabelas.com/product/Minn-Kota-Traxxis-Transom-Mount-Trolling-Motor/701484.uts
24V system
Top speed on my C-22 going down wind at 100% throttle with a modest breeze (no sails up) was about 3.8mph
TORQEEDO 2T:
Note: The Torqeedo is also available in a "remote steer" option, if you have a wheel-steered arrangement.
24V system
Max power at about 2000W
I can EASILY run the C-22 at 4mph in light wind at about 1000W. At 1500-2000W, I can run at 4.5-5mph, but it will drain my batteries pretty quickly (less than an hour). If I run at 3-3.5mph with the Torqeedo in light wind, my batteries will last several hours.
I currently have two banks of two each Flooded Lead Acid batteries, both Group 27, one rated at "160 reserve minutes" (160 min. at 25A load), the other rated at "182 reserve minutes" (182 min. at 25A load). That is, there are two battery banks, with each bank having two 12V batteries in series to give the 24V. The battery switch allows me to select bank 1, bank 2, both, or off. I have a SHUNT wired in the negative side of the load to monitor current out of the batteries (though it sounds like I can measure the voltage drop across the battery cable itself, and use that as a shunt instead! I will be experimenting with that soon!).
The Traxxis is a good motor. I have no complaints. However - it's a TROLLING motor. Because of the pitch of the prop, top speed on a small dingy probably still wouldn't exceed 4mph. It compromises for thrust, not speed. And thus, you probably won't be happy with the top speed (unless you're fishing).
Also, when I ran the Traxxis at high power for 45 min. constant, the power head got VERY HOT. It would appear the Traxxis is not meant to be run at full power continuously (though I didn't notice any warnings about that in the documentation...).
The Torqeedo is designed to be an OUTBOARD. The prop is pitched to drive significantly sized boats. I'd be REALLY curious to see how fast it would drive my 15' plywood runabout! But so far, all I have is data for the Catalina 22 which is a full displacement swing keel sailboat.
My experiences have verified what has been suggested in this forum on several points:
* The Torqeedo will drive your boat substantially faster than a trolling motor, for much less power.
* Running faster takes exponentially more power - more power from the motor, and in turn more power from the batteries.
* At full speed, I can deplete my batteries in an hour. At slow speed, I can run for many hours....
* Tying the battery banks in parallel to reduce the power drained out of each battery DOES allow the batteries to run longer.
* There is definitely a "battery recovery". If I run my batteries down to the point that the motor drops out, I can turn the motor off, and the voltage will almost immediately come back up a substantial amount. I can't run at FULL speed, but I can run at LOW speed for a lot longer.
It's unfortunate that the Torqeedo is SOO expensive (not any more expensive than any of the other options in that power range, but MUCH more expensive than a simple trolling motor!).
I can buy a bank of 2 deep cycle marine batteries for about $200.
I have no doubt that a single Li battery would be MUCH better - but at $2500 for the battery and another $600 for the charger, I'll have to let someone else try THOSE experiments...
Please feel free to email me any questions you might have.
John
From: watergeus55 <moschris@gmail.com>
To: electricboats@yahoogroups.com
Sent: Friday, August 2, 2013 10:13 AM
Subject: [Electric Boats] Outboard for caddy cabin boat
Hi, I've just joined the list. I live next to the River Thames in England and my main project is to be a solar powered river boat. But I have an immediate issue: we live on the other side of the river from the road and use a 15' caddy cabin boat with a 10HP Mariner outboard to get across daily.
The engine is giving out and I've been thinking about replacing it with an electric outboard. I did buy a cheapo on ebay a couple of years back (around £130). Rated "55lb thrust" it was just about usable when the river is as slow as it is at the moment, but no use at all when it's flowing fast, so we never did use it on a regular basis. For one thing only the top speed setting was bearable and that ran down the battery fast.
None of the outboards on the market here seem to deliver much over 80-85 thrust and I'm certainly not going to try another cheapo. It's stopped working and I took it apart this morning. Immediately I withdrew the main restraining bolts, which were stained with rust I knew these things were not made properly.
The Minn Kota Traxxis 80 seems a little more reasonable. It uses 1.34kW max and costs about £650 in the UK. But I'm doubtful it'll give the 4-5mph we need when the river's really running.
Anyone got an opinion on that. Are there other better outboards available?
Chris
The engine is giving out and I've been thinking about replacing it with an electric outboard. I did buy a cheapo on ebay a couple of years back (around £130). Rated "55lb thrust" it was just about usable when the river is as slow as it is at the moment, but no use at all when it's flowing fast, so we never did use it on a regular basis. For one thing only the top speed setting was bearable and that ran down the battery fast.
None of the outboards on the market here seem to deliver much over 80-85 thrust and I'm certainly not going to try another cheapo. It's stopped working and I took it apart this morning. Immediately I withdrew the main restraining bolts, which were stained with rust I knew these things were not made properly.
The Minn Kota Traxxis 80 seems a little more reasonable. It uses 1.34kW max and costs about £650 in the UK. But I'm doubtful it'll give the 4-5mph we need when the river's really running.
Anyone got an opinion on that. Are there other better outboards available?
Chris
__._,_.___
| Reply via web post | Reply to sender | Reply to group | Start a New Topic | Messages in this topic (2) |
.
__,_._,___
No comments:
Post a Comment