Electric motor inboard

Engines, Drive trains, Propellers, Steering, Ground Tackle and other mechanical system
Post Reply
hatuey
Posts: 10
Joined: Mon Nov 09, 2020 7:13 am

Electric motor inboard

Post by hatuey »

Electric motor,

Hello everyone, I'm planning to change my Perkins 28hp engine from my Freedom 35 cat ketch to an 11Kw electric motor.
Does anyone have experience with electric?
I would like to do this because I can no longer stand the smell, noise and vibration of diesel engines... I will install solar, wind and hydrogen fuel cell panels.

Besides, I can hardly imagine the place of solar panels on my Freedom, which is also equipped with a windpilot... If someone has put some on I would like to see some pictures.

A thousand thanks and courage to you who, like me, can no longer access her sailboat. (Belgium prevents you from leaving its territory and the boat is in France 😕)

Translated with www.DeepL.com/Translator (free version)

User avatar
drcscruggs
Posts: 79
Joined: Tue Apr 03, 2018 3:06 pm
Location: Galveston, Texas

Re: Electric motor inboard

Post by drcscruggs »

I have not done the electric motor conversion. I have a yanmar diesel. However, the idea seems sound and would love it if you would keep us posted. I am sure others would like to know your thoughts and obstacles. Thanks for posting.

hatuey
Posts: 10
Joined: Mon Nov 09, 2020 7:13 am

Re: Electric motor inboard

Post by hatuey »

Thanks for your feedback,
I will probably buy an Aquamot 11KW inboard electric motor 48v equivalent to a 28 HP diesel, with 8 AGM batteries of 115 Ah 12 v that is
11040w, if the motor runs at 33% of its power (3666w) and I use the batteries up to 80% (8800w)
If the engine is running at 33% of its power (3666w) and I use the batteries up to 80% (8800w), I would have a range of more or less 2h30 of use.
I think that's enough to get in and out of the port.
I still have to find a clever way to put solar panels on my Freedom 35 cat ketch... And a good wind generator.
Ps

I'm selling my 28hp Perkins engine and its water heating system.
If anyone is interested?

For security I'm going to buy a small 3000w generator... Just in case.

I'll send you some pictures as soon as I start the work. If anyone has a suggestion I'm interested.
Good day to you
Hatuey.

Translated with www.DeepL.com/Translator (free version)

User avatar
GeoffSchultz
Posts: 1089
Joined: Thu Dec 04, 2008 8:39 am
Location: BlueJacket: Guatemala
Contact:

Re: Electric motor inboard

Post by GeoffSchultz »

AGMs are NOT what you want to use. If you use 80% of their capacity, you will kill the batteries very rapidly. You're going to want to use something like LifePO4 batteries.
BlueJacket
1997 Freedom 40/40
http://www.GeoffSchultz.org

User avatar
drcscruggs
Posts: 79
Joined: Tue Apr 03, 2018 3:06 pm
Location: Galveston, Texas

Re: Electric motor inboard

Post by drcscruggs »

I am hardly an expert but thought I would put in my thoughts on the generator. I would consider getting an inverter generator. The reason is they use less fuel and have heard that they are quieter especially if not on full load. Best.

User avatar
newt2u
Posts: 140
Joined: Wed Sep 11, 2019 11:24 am
Location: UK

Re: Electric motor inboard

Post by newt2u »

I agree on the choice of batteries. I use lifepo4 batteries both on my F21 for house, which double up to run a small electric backup outboard. Also I use them for a backup electric supply for my house heating system, i.e. logburner and pumps via an inverter. They are expensive but have a much longer life, especially for deep discharge. You can fully discharge without problems as they include a battery management system the cuts out to avoid damage of over discharge. Hence 100Ahrs means 100Ahrs, not so with AGM. 100Ahrs will cost you around £500 now, prices have dropped since I bought mine. A couple of years ago I paid nearly that for 50Ahrs. Both systems use solar charging via an Epever MPPT charger.
Rockin - F21 twin drop keels - located Milford Haven
Wintered in Shropshire where I am when I’m not sailing

User avatar
mike cunningham
Posts: 378
Joined: Sat Dec 20, 2008 11:21 am
Location: Jacqueline, F30 #3, Discovery Bay, California

Re: Electric motor inboard

Post by mike cunningham »

Totally agree with the desire to eliminate the diesel for the reasons you mentioned.

When my Yanmar 2GM finally bites the dust, assuming it does so before I do, I will also convert to electric. Maybe sooner if there is a breakthrough on the battery energy density front.

However, for the time being I have achieved a very significant improvement on the "smell" front by converting to the use of Renewable diesel

https://www.worktruckonline.com/320806/ ... ble-diesel

It is approved for marine diesels and, although not entirely smell free, a vast improvement over standard diesel.
Mike Cunningham
Freedom 30 (Mull) Hull #3
Build date...June, 1986 . Freedom Yachts USA, sloop, shoal keel
Gun Mount and pole retrofitted (purchased from a Hoyt Freedom 32)
Yanmar 2gm20F , 1600 hrs fixed two blade prop
e-rud and ocean racing equipment

unfetteredalexandria
Posts: 106
Joined: Sun Feb 22, 2009 1:57 pm

Re: Electric motor inboard

Post by unfetteredalexandria »

Looking at the Aquamot website, I can understand why you'd be tempted to choose AGMs, assuming you are thinking of buying their "house brand." It seems they have developed their own brand of AGM's with "massive" plates that they claim are designed for "750 cycles at 75% discharge at 25°C". Compare this to (for example) Torqeedo's claim of "800 cycles with 100% discharge depth at 25°C". So you could buy 2 of the Torqeedo "24V" batteries for roughly $6000, or you could buy four of the Aquamot 200 A-hr 12V batteries for about $2700. Either way getting 48V and about 150 A-hr. But which will last longer? Torqeedo claims 4% of capacity loss per year. I can't find a similar spec for Aquamot; the only thing remotely close is the spec on self-discharge of < 2%/month. And there are plenty of cheaper options for Lithium-Ion than Torqeedo.

And as @newt2u mentioned, all Lithium-Ion batteries will have a battery management system that makes sure you don't ever fully discharge them; when they read 0% they still have 5% or so. And the BMS also ensures that you don't overcharge them, so 100% is may be more like 95% of the real capacity.

When contemplating a project like this, up-front cost can be daunting, so it's tempting to economize on batteries. You may find that you really are only needing that motor to get in and out of the marina, and when you use up the AGMs in a few years, Li-Ion will likely be even cheaper, and/or something better will be available.

On the other hand, there are few things more frustrating than being caught out with a dead motor at the end of a pleasant day on the water, or when things go wrong and you need that auxiliary propulsion. But as we can all attest, this can happen with any type of system!

Thanks for sharing, and please keep us posted!
1984 round-mast Freedom 25
Western Shore of the Chesapeake

Kommy000
Posts: 23
Joined: Sun Aug 05, 2018 8:45 pm

Re: Electric motor inboard

Post by Kommy000 »

In the process of installing Electric Yachts Q10 10kw motor on F32.
Took fuel tank out and put DIY lithium 48v 280ah battery cell where the fuel tank was
Attachments
PXL_20210514_223537848.jpg
PXL_20210514_223537848.jpg (908.64 KiB) Viewed 748 times

Post Reply