12.5' Runabout: Somewhere between Repair and Upkeep

[Stiletto]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

You got a good result. Well done!

[Rich Jones]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

I'd like to hear of your experience with the electric motor.
Speed, battery charge, etc.
The boat looks beautiful.

[wizbang 13]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

Ho Wow !
'course ahm dyen fer the elco moto stats....stat !

[dwr9]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

Beautiful work! Doug

[ABCmeteor]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

The motor is a 20-hp and I'm running two Dakota LiFePO4 batteries in a parallel bank (two 48v 96aH). I've only taken half a dozen trips or so out with it, and at full throttle I'm only hitting about 13 mph. I haven't tinkered with prop pitch or motor tilt at all yet, though.

At full throttle I've got probably an hour and a half or so. The efficiency at lower speeds is really great; I could probably spend all day puttering around the intracoastal and only use up half the bank.

When it comes to charging, it takes me about 12 hours to recharge the whole bank from when I hit the volt drop-off on the batteries (around 15% allegedly, but I've never tested it). Today we took it down to about 18% and I was still getting around 50 volts at minimal idle.

I will say the biggest challenge in this small of a boat has been figuring out where to put the batteries and how to properly encase them. I ended up opting for custom battery boxes made out of 1/4 inch marine ply with reinforced corners. pxl_20230210_201538154.jpg

In addition, the batteries' BMS are only rated for about 100 amp draw each, but the motor is rated at 175 amp max draw. I've only ever hit about 159 amps at full throttle, and I've been fine. If you were to try and install a single battery instead of two, I think the battery's max current rating might be a bottleneck.

The lack of exhaust is amazing; while I have a soft spot for the smell on occasion, it makes my wife sea-sick. There is a similar feature with noise. It is not silent by any means, but at low rpm it can be very quiet and in "neutral" it is just off. The lower-unit is supposed to be standardized and I'm planning on my 10 hour gear oil change. Looking at the maintenance logbook, I'm pretty excited about never having to worry about the bulk of maintenance associated with a combustion engine.

Last things I can think to mention - the motor weighs about 85 pounds and the batteries are 77 pounds each. I know the batteries are much less efficient than gasoline in terms of energy, but given the short range and general use I'm getting out of this runabout, I'm pretty pleased. All that being said, though, I would love one of those fancy toroidal props to see if I get more efficiency out of my setup. If only they existed in the right size and price!

[signalcharlie]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

Our condolences to your family, and thank you for checking in with the Forum. It's nice to visit old friends and see what the boats are up to. Nice work on the resto!

"The efficiency at lower speeds is really great; I could probably spend all day puttering around the intracoastal and only use up half the bank."

We have a 15 foot runabout named WILLOW, and while it was fun to see how fast she'd go, most of the time the water and wind conditions were too lumpy to support that and the passengers didn't get near the enjoyment that the Captain did. Our favorite cruises ran at 5-7 knots, just barely above idle. A few beverages, snacks and nice conversation while you're on the lookout for some of Florida's wonderful wildlife.

IMG_0247.jpg

As for trailers, if you're still looking, the best Boat Trailer guy on the planet, Eddie English, is West of you in Milton FL. He custom built our trailers for us and could set you up. He has a soft spot for small boats and it is fun to see his crew admire and dote over a small wooden boat while the $100K fiberglass rig sits nearby. Tell Eddie that Clark and Skipper sent you.

And if you haven't done so already, we'd recommend checking out the Antique and Classic Boat Society (ACBS). They have a big show and big Chapter in Sunnyland and several members who are fluent in electric motors.

Thanks for sharing the update on your family's boat! Does she have a name?

[wizbang 13]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

thir TEEN?
not ...thir TY ?

[willin woodworks]

Re: 12.5' Runabout: Somewhere between Repair and Upkeep

Nice work!!