Electric propulsion

[Noah]

Ok, I searched him out. Here is a link to his thread. Very interesting.
https://www.facebook.com/groups/catalina34enthusiasts/permalink/1443257403119380/?mibextid=W9rl1R
Hopefully you don't have to join that group (I did) to read it.

[Jim Hardesty]

With my M25XP engine - on two occasions I've had a marina owner and on another a dockmaster say to me when I was throwing off my bow lines, "Aren't you going to start your engine"? which was already running!!! The moral of that story is that you can get the M25XP to run smoothly and quietly!!

Ron, I've also had that happen.  Shamrock's M35 is smooth and certainly quiet enough to have a normal conversation when motoring.  The engine room blower does add to the sound level but that can be turned off.  Much quieter than my Honda 2000.
Jim

[scgunner]

Robert,

I've found that doing your own engineering to be very expensive and the results usually hit or miss. I'd try to find someone who did what you want to do hopefully more than one since it sounds like you're already committed in a big way.

I had a friend several years ago who purchased the boat he'd always wanted, his wife Nina was not happy and said she'd never set foot on the boat. So he named his boat "NO NINA"! You've always got options.

[robertr0816]

Carbon, the motor is not really meant to be run at 100%.
If I want to achieve 4 knots, the 20kw bank should give me several hours of quiet motoring or i can turn on a generator and help the bank along. A 5kw pulsar generator would be able to supply the 30amp to the battery charger and also allow me to run air conditioning, with no issues.
Below is some data of a 32 foot Pearson with the same motor I purchased. I think with electric propulsion, you have to design it for the purpose you intend to use. All I want is to be able to go around long island.
If I was cruising down to the caribeans, then I would add a kubota generator and run a hybrid system.
32 feet Pearson converted

[Steve McGill]

Noah posted the full Facebook link for the 86 electric conversion. It's currently or was listed on Boat Trader

https://www.boattrader.com/boats/make-catalina/model-34/fuel-electric/

[High Current]

I'm currently working on turning mine into a parallel hybrid with the M25XP...slow-tracked while I clear a backlog of other projects.  I previously converted a Hunter 25 to electric and have done a bunch of hull drag and prop calcs for both it and the Catalina.  PM me if you're interested.

Be careful with battery placement as it can affect the trim of the boat.  My old Hunter had a distinct backwards lean with just 72V x 100Ah mounted under the cockpit.

For general motoring, 3-4 kt is a good speed.  Anything more just starts wasting power.   400W of solar charged me during the week and generally kept up with me while cruising - even though I installed an induction stove to replace the portable Coleman.

That said, an electric auxiliary encourages you to use the wind whenever possible.  Motor sailing gains a new relevance.  400W can counteract your morning coffee and getting under way, but would be agonizingly slow without the battery to save it up for shorter bursts. There is still something to be said for a diesel that moves you endlessly in a straight line at 5-7kt when you just want to be somewhere.