Electric Repower (and more!)- Options?

[Captain Pappy]

After some fun with my new "old" boat so far, a recent haul out shows I've got some "fixins" to do, most notably a re-power. Must remove my 42 HP inboard (originally came with a 10HP in '77). I know EVERYONE has an opinion so please don't debate the pros and cons, but I've decided for my needs to go with the extra space and lack of oil and diesel in my bilge for a transom bracket and outboard option. I am however debating electric vs Gas vs new LEHR propane ones, at about 9.9HP equivalent in one or a twin setup with two. New gas Suzuki and Hondas w. 5-6 yr warranty go about $3360 to $4260 based on 10-15hp models. I can craigslist a stronger older one too for way less. I REALLY WANT TO GO ELECTRIC as it has been a green eco dream of mine:

Electric I know of ELCO, Torqeedo and Minn Kota as options. Thus far I see Torqeedo's Cruise 4.0 is strong but I hear it may have gear issues and Minn Kota is dead silent but I may need a twin setup to match the power of the Torqeedo. Elco has an electric inboard too and just came out with a 9.9. outboard. I seem to be at the mercy of Youtube for limited electric info and Ebay for pricing (why don't manufacturers list prices??). One needs the battery bank to support the electric, but it is hard to find info for my questions:

1. Are the engines married to the same manufacturers batteries? For example can I battery bank with Interstate for a Torqeedo or do I need a $3k Torqeedo battery?

2. How many batteries are needed and at what strength? Same is true of Torqeedo's roll up solar panel and controller. How does one budget an electric setup or know where to put the batteries for weight distribution?

3. About the battery bank requirements- Can I also use them for my house bank or do I need a separate one? I cant imagine 14 batteries on a 32 foot Columbia... then again I will free up 300-400 pounds upon removal of the inboard.

Alberto may be my go to guy very soon to see how he did his conversion.

LASTLY, Lehr Propane Outboards... any experienced voices here? Thanks!!

[Captain Pappy]

I'm going to try and bring this post back and expand on it. At this point with technology, are there any electric inboards that could handle a FL to islands or FL to Mexico/Belize crossing? That is including a solar panel/wind generator setup and or generator? What company is a good way to go? I'm looking at Elco, ASMO (The Thoosa line), Torqeedo and Oceanvolt.

[nimblemotors]

If you use an inboard setup, it is fairly easy to use generic parts.
It does need to be configured properly, this takes some calculating.

[a64pilot]

I think the general conscious is electric for a cruising boat isn't real viable, yet.
But if you had a lot of money to throw at the problem, or some good mechanical skills, I'm sure you could do a lot, learn to accept the limitations and live within them
But as I understand it there just aren't ready made solutions yet.

[Boatpants]

I'm working on repowering my C&C 24 with an electric engine as well- I'm not looking from serious crossings as of yet, but I want to be able to sail through the winter without having my gas lines freeze. I am looking into a system that generates with a solar panel, maybe a windmill if I can budget that. What is the precise reason that electric engines are not ready for cruising purposes yet? Is it reliability? Or is it scarcity of parts / mechanics?


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[rumiko dan]

There are a lot of folks going with electric propulsion, but it requires you being fine with the limitations. As I have before, I recommend going to the Yahoo electric boat forum https://groups.yahoo.com/neo/groups/electricboats/info It is full of lots of good information, there are at least four good companies that can supply full kits, and many others that can help with a DIY option. The forum is full of helpful and knowledgeable people. Dan

[Stumble]

The problem, as has been mentioned in thread after thread, is not the motors it's the batteries. There just isn't an energy storage method other than fossil fuels that contains enough power to be meaningful on a long trip. Renewables (solar and wind) can help, but you hit a charge rate limitation for the batteries quickly, or need even larger battery banks (or not quite ready for prime time battery chemistry).

It is absolutely possible, but the limitations placed on the boat are such that most people aren't willing to make the switch.

[GrowleyMonster]

The way you use the motor largely determines the practicality of electric drive. For just docking and maneuvering, it is perfect, with many advantages over internal combustion. For sustained long distance motoring, not so good at all. It can be done, but barely. For instance, in calm water I can do about 2.4kt with 10 amps coming out of the batteries. Call it a kilowatt. That's pretty slow. I can go a lot faster, but the power demand goes up faster than the speed. But let's say for a 27 foot 7600lb boat this is the minimum usable power level. Now, you might think okay, I just need a kilowatt of solar panels to power the motor indefinitely. Unfortunately you would probably actually need more like 4kw of solar panels to keep the prop turning around the clock, maybe more, and this is in a sunny area. That's an awful lot of panels. More than the hypothetical 27 foot cruiser can carry, actually. Add a wind generator? A 500w contribution from a wind gen would be a big help. But 500w would call for about an 8 foot diameter turbine blade set. Half the diameter would give you 1/4 the power.

A hybrid system can make a lot of sense. Yes, it is somewhat inefficient to run a diesel or gas engine to generate electricity to charge batteries to power a motor to turn a prop. But if you get an average of 10a into the batteries from renewable energy, or even half that, then your fuel economy has improved even over a direct coupling of engine to prop. Some days your solar and wind energy harvesting will be much greater, some days less. Some days may allow running on renewable energy only. Other times, the engine is the backup dependable power source that keeps the boat moving.

A purpose built pure solar boat is of course possible and has been done. But even with sound engineering and a big budget, speed is like watching paint dry, and a lot of design compromises have to be made at the expense of well, lots of stuff.

One for of renewable energy is very practical for pushing the boat under nearly any conditions. That is wind on sails. So that puts us right back where we started... A sailboat with electric auxiliary propulsion. Charging the bank from the prop when sailing at high speeds is doable if you have several days of charging between use of the motor. A large spread of solar panels can do the trick, if the motor is not used. A catamaran built as a solar sailer could carry an awful lot of panels. A small generator could put a charge on the bank in the absence of significant solar or regen charging.

So, an electric motor is practical on a cruiser, but not practical for cruising. If you motor a lot, diesel is still king. For motoring out of a calm, maybe. For maneuvering only, electric is perfect.

Yes, you could do away with the dedicated house bank, but I wouldnt. In fact, a backup 48v bank would be a good idea. Normal 12v loads can be taken from the bank via a dc/dc converter. Redundant isolated power sources are a darn good idea, whether it is a 48v bank and a 12v house bank, or 2 48v banks which is preferable.

[Lodesman]

Another forumite, Mbianka has done an e-repower, and blogged about it: THE BIANKA LOG BLOG: Going electric: Part 1: The why and how

[GrowleyMonster]

One thing I didn't mention is motorsailing with electric power. In light airs you could certainly get a small boost in speed from running the motor on solar power at low speed, and not deplete the batteries. I could see running 5a from a big solar spread and turning a 2kt run in light air into 3.5kt, for instance. Sometimes a little bit of power is enough to make a difference.

The Bianka Blog was a major inspiration and source for ideas when I was still planning my repower. Mike makes good use of his electric drive by having a flexible system and being resourceful. A great read, for anyone thinking about going electric. He combines wind, solar, a portable generator, sail, batteries, and motor in a cost effective way and while he doesn't eliminate fossil fuel use entirely, he does make minimum use of it while still getting where he wants to go.

[GrowleyMonster]

Some test data. Lake Pontchartrain, calm day, breeze on the beam, average of both directions. Estimated range can be calculated from assuming 100ah drawn from the bank, divided by current to get run time, multiplied by speed to get nm. For instance at 1a I should be able to draw for 100 hours, giving 100nm range at the 1 amp setting. At 20 amps I should be able to run for 5 hours at 3.3kt giving a range of 16.5nm.

1a 1kt
2.5a 1.4kt
5a 1.9kt
10a 2.5kt
15a 2.9kt
20a 3.3kt
25a 3.6kt
30a 3.8kt
35a 4.1kt
40a 4.3kt
45a 4.5kt
50a 4.6kt
55a 4.7kt

Two things I really need to do. First, I underestimated the need for a quality high current charger. 15 amps is NOT enough for a 220ah bank. I need at least a 30a charger, preferably one that can deliver an equalizing charge, which is 62 volts for a 48v bank. The charger came with the Kelly controller and the voltages are too low and not adjustable. I probably should build a charger that I can configure to my needs and preferences but it is a daunting project.

Second, the control setup is awkward. I have an on/off switch, a fwd/n/rev switch, a recent pot, and a throttle pot. I don't intend to sail the boat any more so I can eliminate the regen. I want to have only the power on/off switch, and a single knob for throttle and reverse/neutral/fwd. Pointer straight up for neutral, to the left for reverse power, to the right for forward. Further for faster, less for slower. I will probably use an arduino for processing the signal from a 10k pot using the 5v control voltage from the controller, with the midpoint being converted to 0 throttle, 0v to full reverse, 5v to full forward. The single knob control will be more intuitive and easier/faster to operate.

Since I will have an arduino board in the control box, maybe it would be cool to also have a 2 line LCD display right on the control box, showing battery volts and state of charge percentage, amps into the controller, and prop RPM. What I got now is just an analog shunt ammeter and analog voltmeter jumpered in, laying loose on top of the battery box. Difficult to read and inconvenient. For now, I will mount them on a piece of acrylic, along with a digital hall effect tachometer that I haven't installed yet. I will mount that on a box of some sort so the connections aren't exposed. But a 2 line display presenting the data right there on the throttle box will be super.

I tried to get the configuration program for the Kelly controller to run on my laptop, running Linux, but no joy. In Wine the app tries to start but says it can't find the controller. I tried all sorts of things and I can't get it to go. That is one of the things that absolutely sucks about the Kelly controller. The tech guys want US to use the operating system that THEY use. They don't understand the American concept that the customer either gets it his way or gets it elsewhere. They are zero help on this, and other issues. They also label meters only in a percentage of configured current and voltage parameters, not volts and amps, and so the data from the supplied meters is ambiguous and basically useless. They defend this stupidity by claiming they would have to write a separate configuration for each size of controller. In fact they only need to change certain constants in a configuration file for each controller but they think they know it all and I am just some retard who doesn't understand that the vendor makes the rules and the customer shuts the hell up and takes what he is given. And they are mad at me for not ordering my motor through them.

Bottom line, if you use the Kelly controller, don't expect much useful technical assistance from them, make sure you have a windows or Mac computer, and don't waste your money on their kit. Buy controller, fuse, contactor, diodes and resistor, and heat sink, put it together yourself. I am waiting for Sevcon to get their act together and make a line of controllers that can be configured on a proper Linux or Android computer, without paying $200 for a special programmer doodad. That's pretty ignorant and stupid, as well.

I only get a max of about 60 amps or a bit less of current. I think it is hitting a speed limit in the controller. The original 12" 2 blade folding prop doesn't seem to be loading the motor enough to develop peak power. I will be replacing it with a fixed 3 blade next year. Possibly it would have been better to not use a reduction gear with this 4201 motor, which is meant to be ran slower than the similar 0907, but I didn't want to have to diddle around with a thrust bearing when I could just mount right up to a Baldor reduction gearbox. But the 3 blade prop ought to give me the full 5kw power from this motor and controller.

Another thing I want to re-think is the motor mount system. I will build a bed framework that does not need adjusting, and the motor faceplate will have separate adjustments for side to side, yaw, fore and aft, pitch, and height. Also I will make it slightly wider to accommodate the 10kw size Motenergy motors. The idea is for the design to be more or less universal for all boats originally equipped with Atomic 4 or Universal Diesel motors, using the Motenergy electric motors. Mounting the electric motor properly is probably the most intimidating part of a full DIY electric repower. This is why a full turnkey system or a professional installation is worth several thousand dollars more. Well, and the engineering. With an open source mount easily built with no welding out of cheap mild steel angle iron and 1/8" sheet, a DIY setup for 25 to 35 foot boats is a lot more feasible for a lot less technically inclined owners. The only machine shop type equipment needed would be a cheapo drill press from Harbor Freight, to drill accurate holes in 1/4" steel for 3/8" bolts. And a saber saw. No other power tools needed.

If there is enough interest, next year after I redo the mount and control box, I might make an Instructible tutorial on a generic setup for a small sailboat with a Motenergy or compatible motor. Maybe an open source kinda thing that can adapt to new technologies and sources as time goes by, with an eye toward keeping it cheap but also easy for regular folks to do.

To reiterate, I got my parts from:

Kelly, for controller kit including inadequate charger, useless meters, nice mounting plate, contactor, and fuse with KBL48301X 48v 300a peak, 100a continuous controller. I recommend thinking carefully about going with a Sevcon controller, though. Neither one is perfect. They don't care what we want.

Electricmotorsports for Motenergy 0201014201 BLDC 5kw motor. It was cheap so I got a spare, too. Later, after initially planning on direct drive, I also got a 2:1 Baldor enclosed gearbox from these guys.

Sams Club, for batteries. 8 GC2 6v golf cart batteries, for 48v and 220ah.

McMaster-Carr, for shaft, couplings, angle iron and sheet steel, and other bits and pieces.

Home Depot, for stainless bolts and hardware, and wood for my battery box. Also 2/0 cable for connecting batteries, controller, and motor.

Radio shack, for parts for control box.

Ebay, for meters, digital tach, digital volt/amp meter, (still in transit)

Alternate cheap source for motor and controller is Golden Motor, but they couldn't beat the price I paid for Kelly/Motenergy setup.

For kits, look at Thunderstruck or Electricmotorsports. Thunderstruck also has a nice open belt reduction gear.