Project Log - New Keel, Who Dis? (Pearson 26 to Electric Cruiser)

I think the calculations were for watts at the prop, like a gas outboard. Looking at the power / speed results others are getting on YouTube with trolling motors, I don't think they are wildly off.

As for the hybrid approach, I suspect you may be correct. We will see! But it is clear I can cruise around at 3 to 4 MPH with electric.

I understand the issues with lead batteries, but at the current price points using lead carbon to tolerate slow and partial charging (and I can afford more Ah to reduce the Puekert effect!) I feel it may be worth it. But if I use a gas motor this year, I can wait to see what the lithium prices are next year!

Yes, for the Navy 3 they tested that with a small skiff.

 

Depending on product and use case, Lithium 18650 packs might already be cheaper than good lead acid batteries if you include actual usable capacity and lifecycle recharge cycles.

 

The more exotic LiPos are imo no go for amateurs. With big packs catastrophic events are serious stuff. LFP are way safer.

 

There are ways to DIY LFP, but even then, I'm not interested in doing that. I'm staying the hell away from LiPOs on a boat.

 

The kilovault LFP batteries look like a good option: KiloVault HLX Series Lithium Solar Batteries | altE (altestore.com)

The biggest initial advantage of lithium is that it would be light enough to pull from the boat and bring into the house or garage for charging.

 

That price seems pretty good. For my project (48V and more of a house battery for aliveaboard cruiser) I want to DIY with LiFePO4 prismatic cells. Mostly because I'd like to be able to understand and replace each individual part. Ideally I'd want the charger and BMS to be open source so I could replace something like a busted capacitor myself.

Also theoretically DIY and using a better and maybe wireless BMS can give you more safety. Not sure if this is true or even applies to lifepo4 but I read a comment that some battery packs use cheapest BMS that can fail and then no longer balance or protect the battery pack.

For safety I've been wondering too although I'm not that worried with LiFePO4. But maybe there is some kind of design for an external pod. Or placing battery so they don't easily get hit. And is not in the bilge in case of a bit of flooding. And if they catch fire the heat can escape without setting the rest of the boat on fire. Boatsmith mentions a seawater pump to flood the batteries to douse them. A bit extreme but should provide best protection for the boat.

 

The custom ordered trailer exists!

 

That's one sexy trailer! Do you know how much it weights / gross weight it can carry?

 

10400 lbs GVWR - which should be plenty for a 5000 lb boat.

 

Assuming I can get the trailer and the boat to my yard tomorrow first step will be pulling the seacocks so I can rehab them.

 

Thanks, nice. I'm just curious about the weight of an aluminum trailer compared to steel. Do you know the weight by chance?
Maximum gross weight for a trailer for a normal car and drivers license here in Europe / Germany is 3.5t / 7700lb and the steel trailer I'm looking at weighs about 580-720kg depending on length. The aluminum trailer I've found isn't lighter in weight either.

Sorry for derailing your thread - but with a trailer like that how do you expect anyone to talk about your boat??

 

The maker thinks about 1600 lbs.

I'll weigh it and the boat eventually.

 

The trailer has been delivered to the yard! Now to register it! And pay taxes on it.

 

I have finally trailered the boat to my local storage yard!!! The trailer looks good. I won't be able to start on the keel until I have it at my house for a few weeks and get it jacked up, but there is plenty of other stuff to do.

 

I finally have the boat in the backyard and have started work!

So far, I have:

* Had the marina remove the keel, mast, and rudder. (Mast and rudder are for sale!)
* Bought a custom trailer (ouch!)
* Built a frame and covered it with a tarp
* Started yanking off hardware

The big tasks before putting it back in the water with a 5hp long shaft outboard for it's first season:

* Replace cast iron keel with long fiberglass keel / skeg, with lead and/or gravel embedded for weight.
* Replace / reseal cockpit drain seacocks
* Remove toilet seacocks and fiberglass
* Replace / reseal depth and speed sensors
* Replace motorwell drain with rigid fiberglass tube
* Remove existing lifeline system and upgrade to more 30" stanchions and double lines. I have a 5 year old and a nervous admiral.

Please note that I will be doing a roll period test and crew movement test before taking the boat out. I may need to add ballast in which case I will be putting steel plates on top of the keel but under the floor boards.

After the first successful year with a gas outboard I plan to convert to solar electric with heavy duty trolling motors.