John,
Your runabout is not unlike mine and I run a Torqeedo 4R. It operates in a semi-planing to planing range, about 12-13 mph. Mine is 19' x 4.5' and draws 3-4 inches with a very flat bottom from midway to stern. You can see the design at D.N. Goodchild's site under Whiz: An Outboard Speedster http://www.dngoodchild.com/5388.htm. I just increased all the offsets by 20% to get it up from 16' to 19'. The hull weighs about 250 lbs.
The trick to planing for any distance is a lithium battery bank. She will plane with Pb but not for long. With 5 Optima grp 24's and me on board she did 14 mph.
My present bank is 18 cells 160 Ah Thundersky, (now Sinopoly), about 60v. It weighs 225 lbs. She won the Wye Island Electric Boat Marathon averaging a little over 11 mph. The summer water temp made the motor cut back to 3.5 kw rather than 4.5 kw.
Yours looks like a good hull for planing and the weight is about right.
Good luck,
Ned
On May 8, 2013, at 3:00 PM, oak wrote:
Are there any of the Minnkota's that work with remote (wheel) steering??? I didn't think there were.The boat is a 14' wooden outboard runabout.Here's my web site on the project: https://sites.google.com/site/danrobertstx/home/boat-building/mischiefHere's the site with the original plans: http://svensons.com/boat/?p=RunaboutsOutboard/playboyIf you like looking at old boat projects, take a look at the plans - they're a hoot.Anyway, it's a small wooden boat that currently has a 30hp outboard. At 200 pounds, it really does weigh down the back end of the boat. Plenty of power, but a LOT of weight. At planing speed, the boat starts porpoising (bouncing up and down front to back). I'm getting ready to try adding trim tabs to see if that will calm the porpoising (which is currently limiting my top end speed), but I also had thoughts of converting the boat to electric.Since the boat is WHEEL steered, the Torqeedo 4R would be good. And I'm curious if 10hp might be barely able to get the boat up on plane.Even if it can't get up on plane, it would still be fun to just troll around in. I'm also starting to think about maybe building another boat from scratch that would be just a little smaller, and quite a bit lighter (since I wouldn't be building it for a 30HP engine).If I had it all to do over again, the Torqeedo 2R would provide 6hp, plenty for just puttering around, and be easy to get going with 2 x 12V batteries.The motor is pricey, but otherwise it's easy to set up and run, and no worries about gas, impellers, tuneups, etc....If the 4R would get a small boat up on plane (they show that with RIB's, but not sure how practical that is with a 12' wooden boat...), then maybe it's worth just sticking with the 4R. The 4R is only about $500 more than the 2R, and has almost twice the power (at twice the battery headache).John
From: Steve <sstuller@netzero.com>
To: electricboats@yahoogroups.com
Sent: Wednesday, May 8, 2013 2:22 AM
Subject: Re: [Electric Boats] 24V to 48V ??
I don't know how small your "small" boat is but why not try a 12 volt MinnKota? There would be only one battery and if you buy the PWM version of the MinnKota the battery will last longer. Thanks. Steve S.
--- In electricboats@yahoogroups.com, oak <oak_box@...> wrote:
>
> You have a good point, though I guess the only step down for "smaller batteries" would be maybe 4 lawnmower batteries. Â That would save significant weight, but would probably have VERY LIMITED range for the Torqeedo 4R.
>
> Bottom line - best option would be either to stick with what I've got and deal with the weight, or eventually haul off and buy a Torqeedo 2R.
>
>
> ________________________________
> From: matt elder <mattelderca@...>
> To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> Sent: Tuesday, May 7, 2013 4:16 PM
> Subject: Re: [Electric Boats] 24V to 48V ??
>
>
>
> Â
> It would be cheaper and easier to just buy four smaller batteries. In fact, you would need the same weight in 24 volt batteries as you would for 48 volts. The converter does not increase the power (watts) available, so to get 2000 watts at 48 volts you need 41.6 amps. To get the same 2000 watts at 24 volts you will need batteries capable of providing twice that, 83.3 amps!
>
>
>
>
> Â
> mattelderca
>
>
> >________________________________
> > From: oak <oak_box@...>
> >To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> >Sent: Tuesday, May 7, 2013 4:46:46 PM
> >Subject: [Electric Boats] 24V to 48V ??
> >
> >
> >
> >Â
> >
> >
> >I suspect the answer will be "no", but just thought I'd ask....
> >
> >
> >
> >
> >I have a Torqeedo 4R that I'd like to try on a small boat. Â But I don't want to have to lug a 48V battery bank out there.
> >Is there hefty DC-DC converter that will step up 24V to 48V at up to 2000W? Â (and that's not crazy expensive)
> >
> >
> >This is just for an experiment - I realize there would be penalties - but it would be better than buying another Torqeedo (2R).
> >
> >
> >Thanks,
> >John
> >
> >
>
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