tunnel hull boat EV conversion

[flipflop]

Hey all - I’m looking to pick your brains on a project I have been dreaming up for a while. I have a 23ft tunnel hull boat without a motor and I want to figure out an electric inboard solution. The link here is the same boat:

https://boats-from-usa.com/obsession/obsession-stiletto-126613

My goal is to hit 45-60 mph and don’t have any significant range expectations. I have been looking at the tesla kit motors from EVWest.

https://www.evwest.com/catalog/prod...d=476&osCsid=78426a6296023a4fbef0dc8cd1a47617

https://www.evwest.com/catalog/prod...d=498&osCsid=78426a6296023a4fbef0dc8cd1a47617

I was hoping to power the motor with 20 1kW 36V batteries in whatever configuration works best. I also have multiple charging solutions.

I was wondering if you all think the boat’s conversion to electric will impact weight distribution negatively with the tunnel hull design? I know tunnel hulls are a popular choice for RC boats but didn’t find much out there on any conversions.

Anyways, thanks for you all being so knowledgeable - this community is awesome.

 

[bobkart]

You'll want some idea of what power level will achieve your speed goals. You can be pessimistic and overbuild power-wise, but then costs go up. Off the top of my head I'm thinking 120hp (90kW).

On weight, you can try to determine how much weight you'll lose by removing the existing engine, fuel tank, etc. Sounds like you'll have about 250 pounds of batteries (if you meant 1kWh rather than 1kW on those 36V batteries). Add that and the electric motor/etc. weight back in to see where you land in terms of heavier-or-not compared to the gasoline setup. Since you state that range isn't a large consideration, you can reduce battery size if you need less weight. But LFP usually can't supply 90Kw from a 20kWh bank (that's 4.5C). So LiPo or NMC chemistry is likely called for, but then you have thermal runaway potential. LTO will also work, and has no thermal runaway potential, but that chemistry has poor gravimetric energy density.

On weight distribution, I think you can have the weight located fairly close to where the gasoline setup weight was. A little bit forward of that is probably okay, and may actually help.