Hi Michael,
I can answer one of your questions at least...
The 360ibl has two motors and two controllers which does provide a level of redundancy.
Others have addressed the direct drive vs. reduction question and there is nothing I can add there.
Using the regen function the way you suggest doesn't make a whole lot of sense. As far as I can see you would simply be wasting power to no useful end. I'm sure there are other, more efficient ways to balance two battery banks (like tying them directly together for example).
Keep asking questions and good luck with your project!
Jim McMillan
PS. For what it's worth, my brother Scott owns Electric Yacht. I've done a few installations and am familiar with his products, but am not directly involved the business and don't always keep up with his latest developments. I'd suggest giving Scott a call if you want straight answers. He designed all their systems, so nobody knows them better. His contact info is on the EY website.
--- In electricboats@yahoogroups.com, Michael Mccomb <mccomb.michael@...> wrote:
>
> YES and I have run across the 360ibl.... i hate to be asking about too many things at once so i decided to leave questions specifically about the 360ibl until later... but now that you mention it i do have a couple...
>
> does anyone have any specific experience with this doubled up 180ibl system? are they using a single controller to address the needs of both motors? (if so a standby redundant controller would seem to be in order)
>
>
> wouldn't the motors be slightly more efficient at turning battery power to motion if the belts were eliminated and the connections were directly motor to motor to propeller shaft?
>
> i sort of asked this once before but it comes back around here.... hypothetically, if one were using one controller for each motor, set one to provide power while leaving the other in a regen setting mode wouldn't the net result be to transfer energy from one battery bank to the other while providing propulsion and losing just a bit to resistance or drag if you will?
>
> seems like the regen function would also be able to balance battery sets through differential settingsÂ
>
> gonna look up PMAC
>
> haven't spoken to anyone at any of the various system providers yet, just you guys
>
>
>
> ________________________________
> From: James Sizemore <james@...>
> To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> Cc: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> Sent: Tuesday, September 6, 2011 7:19 PM
> Subject: Re: [Electric Boats] Re: hypothetical question...
>
>
> Â
> What you are describing is pretty much the Electric yacht Quietorque 360ibl, two 9hp motors and controllers driving the same belt. Â
>
>
>
> On Sep 6, 2011, at 5:17 PM, Michael Mccomb <mccomb.michael@...> wrote:
>
>
> Â
> >Thank you.
> >
> >I will check out the items you point to and understand what you are saying.
> >
> >
> >
> >It seems that it would be important to have redundancy built into an
> electric propulsion system if one were to be out in the wilds so to
> speak. I wouldn't expect a chandlery or any other equipment supplier to be able to provide parts or expertise needed to adequately deal with
> repairs to an electric propulsion system.  Sometimes diesel repair can
> be a problem but electrics, no way.
> >
> >
> >Therefore it has occurred to me that instead of, for instance, a 10kw system it
> would be better to have two 5kw systems that were completely independent of each other. In that way should one motor or one controller
> breakdown one would at least be able to limp along.Â
> >
> >
> >
> >My first thought would be to provide perhaps enough power in one motor to reliably
> provide 70% of hull speed. 70% of hull speed is frequently sited as a
> VERY power economical way to cruise. When both motors were operational
> one could attain full hull speed quite handily as long as one was
> willing to sacrifice a lot of battery/gen capacity in the effort.
> >
> >
> >Hi priced systems may very well be more reliable but, to borrow a concept, a sort of RAID (redundant array of inexpensive drives) approach might
> be both less expensive and more robust?
> >
> >Thoughts???
> >
> >
> >
> >
> >________________________________
> >From: Eric <ewdysar@...>
> >To: electricboats@yahoogroups.com
> >Sent: Tuesday, September 6, 2011 5:03 PM
> >Subject: [Electric Boats] Re: hypothetical question...
> >
> >
> >Â
> >Hi Michael,
> >
> >I suggest doing a little research on the "White Zombie" an electric drag racer that has been running joined DC motors for quite some time. he has also used twin controllers to get past the 1000A controller limitations that existed for some time.
> >
> >For boating purposes, I don't think that one needs to use two motors until you get much farther up the power scale. If you need them, 20kW motors aren't that difficult to source.
> >
> >Fair winds,
> >Eric
> >Marina del Rey, CA
> >
> >--- In electricboats@yahoogroups.com, "Michael Mccomb" <mccomb.michael@> wrote:
> >>
> >> if one were to hook two 10kw motors utilizing separate controllers and battery banks together so that the two motors were driving a single load wouldn't any imbalance in contribution of effort by the two systems tend to result in a transfer of power from the over contributing system to the lessor contributing system? secondarily if one could have the controllers differentially contribute amperage based on which battery bank was least charged couldn't the resulting system serve to balance the two battery banks? i would also think that the balancing could be attained in either powering or regeneration modes
> >>
> >
> >
> >
> >
>
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