ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

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Fuzz
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by Fuzz »

On a different subject how is the Covid goat rope thing doing there? Is the country still mostly closed to those from other countries?



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BarraMan
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by BarraMan »

Fuzz wrote: Thu Apr 21, 2022 8:30 pm On a different subject how is the Covid goat rope thing doing there? Is the country still mostly closed to those from other countries?
We are now pretty open - unfortunately! Even the unvaxed from overseas are now allowed in, without needing to quarantine.

I’d be happy to see the unvaxed banned from everywhere! :help:

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glossieblack
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by glossieblack »

Thanks Jaysen, Jeff, Tom and Fuzz.

Barra Man has already answered the Aussie Covid question. Thanks BM.
Jaysen wrote: Thu Apr 21, 2022 8:50 am can you define "destroy" a bit more clearly?
All eight portside cells were fully discharged to zero volts. Some I can individually trickle recharge to nearly full, the rest to around half. Unfortunately, none hold the charge.

The supplier advises: If one or more cells goes to zero volts for a period or is reverse polarized by discharge currents for even a few seconds then the battery will be permanently damaged and become unbalanced. A subsequent recharge carries a significant risk of catastrophic failure.

Catastrophic failure means explosion or fire, so the eight batteries have no Skinnydip future.

I'm still pondering whether to: replace the batteries to retain a 48V 100Ah battery bank; reconfigure down to a 24V 100 Ah bank; or scrap the e-drive subsystem altogether, and sell of the remaining components.

Reaching an e-drive decision quickly is not a priority. Getting Skinnydip back on the pick in the Noosa River and enjoying her as a diesel driven runabout for 2-3 months before we go cruising in Great Sandy is.
Currently building Jacques Mertens ST21 "Skinnydip". Boating adventures: Splash testing and using 'Skinnydip, as a basis of further building refinement; Adams 44’ sailing sloop "Great Sandy" (cruising and maintaining); Iain Oughtred Feather Pram "Mini Dip" (building); Jacques Mertens R13 "Wood Duck" (built and due for maintenance).

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cape man
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by cape man »

Sounds right to me.
The world always seems brighter when you've just made something that wasn't there before - Neil Gaiman

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Jaysen
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by Jaysen »

Stay with the 48v EDrive. The error in this case is simple and not indicative of a real design flaw. You can add a low voltage shutoff (I can design one if needed) to basically disconnect the battery bank if it drops below a specific voltage. This would prevent recurrence for the same causal.

That’s the simple answer. Then again, there are the $$$ and fact that someday other “not GB” will need to maintain the system. That may be more difficult unless the inheritors understand the value of the system way exceeds the cost.

I would strongly recommend immediate removal of the bad bank. I’d hate to see someone crank the motor over and those thing wave goodbye to the universe. No need to recreate mobster movie scenes on the noosa. :D
My already completed 'Lil Bit'. A Martens Goosen V12 set up to sail me to the fishing holes.
Currently working on making a Helms 24 our coastal cruiser.
“Mark Twain/Samuel Clemens” wrote:Eat a live frog first thing in the morning and nothing worse will happen to you the rest of the day.
Jaysen wrote: Mon Apr 29, 2019 3:44 pm I tried to say something but God thought I was wrong and filled my mouth with saltwater. I kept my pie hole shut after that.

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BarraMan
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by BarraMan »

Michael, I feel your pain!
I am very reluctant to suggest this but ................ 8O
As you know, to access the upper reaches of the Noosa everglades you need an electric propulsion system of some sort.
A far less elegant solution than your eDrive would be to mount a 112lb 32V Minn Kota motor on the bow of SkinnyDip, combined with an off-the-shelf large capacity 32V lithium battery. It would spoil the boat's nice lines - but would get the job done. You have seen mine in action first hand.
I am thinking of replacing the 3 x AGM batteries that run my Minn Kota with lithium - and saving about 60 kg (130 lbs) dead weight in the boat.

Then again, my solution will set you back the best part of $10,000 (!) - compared to the cost of replacing your lithium battery bank?

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glossieblack
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by glossieblack »

Thanks cape man. And thanks Jaysen and Lee, your suggestions have been added into the 'for further consideration' mix. :D
Currently building Jacques Mertens ST21 "Skinnydip". Boating adventures: Splash testing and using 'Skinnydip, as a basis of further building refinement; Adams 44’ sailing sloop "Great Sandy" (cruising and maintaining); Iain Oughtred Feather Pram "Mini Dip" (building); Jacques Mertens R13 "Wood Duck" (built and due for maintenance).

Fuzz
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by Fuzz »

I know very little about your e-drive system but I am wondering if it can be run at 48 volt as is with half of the batteries? I know you would lose range but it would let you prove out the system and then go from there?

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Jaysen
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by Jaysen »

I think each bank is 24v@100ah (8 cells at 3.3g standard) so he has to run them in series to make 48v. Not sure if the controller/motor can be programmed to operate on 24v. The end state would be reduction in speed or run time (possibly both).
My already completed 'Lil Bit'. A Martens Goosen V12 set up to sail me to the fishing holes.
Currently working on making a Helms 24 our coastal cruiser.
“Mark Twain/Samuel Clemens” wrote:Eat a live frog first thing in the morning and nothing worse will happen to you the rest of the day.
Jaysen wrote: Mon Apr 29, 2019 3:44 pm I tried to say something but God thought I was wrong and filled my mouth with saltwater. I kept my pie hole shut after that.

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cape man
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Re: ST21 'Skinnydip' build, and boating adventures, Noosa, Australia

Post by cape man »

I need to walk away from this for a time and collect my thoughts.
Reaching an e-drive decision quickly is not a priority. Getting Skinnydip back on the pick in the Noosa River and enjoying her as a diesel driven runabout for 2-3 months before we go cruising in Great Sandy is.
You guys need to read his posts better. Based on what I read he really doesn't want to think about it for a while, which I totally understand and respect. Move on.

Me, I need a pic, or better yet a video, of the new feather pram underway to Skinnydip, and maybe even a video of you crossing the bar under diesel power.
The world always seems brighter when you've just made something that wasn't there before - Neil Gaiman

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