|Topic Review (Newest First)|
|07-06-2010 06:24 PM|
When I think back on the state of electrical storage batteries from just a few decades back, and compare that to where we are now, I get a little hopeful that things may all improve... but they are still a long ways off. Efficiency of conversion & storage is just not there yet for me at least.
Maybe someday soon I'll plug in something like a laptop computer battery and my Jeep will come to life. And then that will upsize to boats, etc.
|07-06-2010 05:22 PM|
Originally Posted by tomwatt View Post
|07-06-2010 05:12 PM|
Originally Posted by sailingdog View Post
At any rate, getting much motor-sailing time out of a battery bank leaves one with the choice of buying a big pile of heavy, expensive batteries and nursing them along or buying a small pile of heavy expensive batteries and killing them early by drawing them down below 50% too often and then having to repeat the buy.
I really wish I could see a way to make a good working system out of electric, but for now can't see it paying off until batteries evolve a bit more.
|07-06-2010 01:58 PM|
|sailingdog||am buying = not bought yet...|
|07-06-2010 01:37 PM|
I think the point is he already bought and paid for it... that's what I read.
Now comes the issue of recharging and battery life/storage to deal with.
As of the moment, there is no lightweight inexpensive storage system to support the electric motor for any kind of extended motoring.
For the kind of use I was pondering (some mild motorsailing on the ICW when sailing wouldn't be practical), I ended up computing that I'd need another 1,000 lbs. worth of batteries plus have to park and recharge for 2 days for every days' worth of powered use.
So in the end, an outboard motor made a lot more sense.
|07-06-2010 10:04 AM|
I'm not a big fan of electric power on boats due to the limitations on cruising range, the increased complexity and the inability to "refuel" the boat quickly.
Unless there is some major reason for you to get an electric powered boat, I would recommend you not do so. Also, the price of the boat should reflect the limitations that are being imposed by such a radical modification.
Originally Posted by mszczepa View Post
|07-06-2010 06:28 AM|
How much does your boat weigh? thiis is what I got off the suevey - SEVCON Millipak controller and contactor
- SEVCON calibrator don't know what they are or what they do thanks Mark
|07-06-2010 06:11 AM|
|mszczepa||the idea is to have the gen there as a backup to extend miles if needed Where I live the winds are normaly light in the summer and there are Islands all over the place to visit . I am the type of sailer who enjoys the trip not needs to get to a location . If there is wind I sail it ,and because of my racing background I can't sit still I need to get as much out of her as posible. There are times that it will be nice to go on an exstended cruise and it is these times that I need the extra .My other optionis to make a well or put a bracket on the back . I did buy the boat and I think I got a good deal because I paid 4700 for her. I have 1500 to put into her and I am trying to figure out which is the best way I love the idea of going somewhat green and the best time on a boat is when the diesl is turned off but I need to know I have at least 20 miles out of her thanks Mark|
|07-06-2010 12:52 AM|
Originally Posted by mszczepa View Post
One big difference between Mark F's Ericson 27 and the Bristol 33 you are looking at is displacement. the Bristol 33 displaces 50% more than the Ericson 27. That extra weight is going to have an impact on both usable range and usable speed. With your current capacity and your need to travel 20 miles on a charge, i think you might be cutting it beyond close, especially if the wind is on your nose
In any event, if you are going to add a generator to try to make up range, isn't that sort of defeating the purpose of going electric in the first place, and simply overcomplicating the system?
Unless this boat is at least $5000 less than similar fossil fuel powered models, and unless you have another $1000 to throw at this boat to make it fit your needs, you may be better off if the keeper of the funds doesn't open the purse.
|07-06-2010 12:50 AM|
|Mark F||I have two separate banks (sets) of batteries. One is made up of four 12 volt group 27 AGM batteries connected in series. Each battery is rated at something like 90 amp hrs, by connecting them in series you get 48 volts and the amp hrs stay the same - 90 ah. The other bank is four group 31's rated at 110 ah, so 48 volts and 110 ah. Your 130 ah Trojan's are a real good start and should do fine for local stuff. I like having the redundancy of a second bank even if I rarely need to dip into the second bank. You should find out what the amp draw is for 3, 4 & 5 knots of motoring boat speed. Also the proper prop is important to performance. I started with a fixed two blade 11x8and got 3 knots at a 20 amp draw. Now with a fixed three blade 12x10 I get 4knots at 20 amps. Does the Bristol have a way to monitor the batteries?|
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