T-Pain Is On A Boat: [Electric Boats] Fugu electric conversion performance

Hi,

My summer has been very short. The conversion took much (much) longer
than anticipated and is still not finished, despite now being
operational.

Here are some numbers that I have extracted from my first 4 sails.
Just a note, I have only tested at 30A, 45A and 82A (full throttle)
settings since my time on the water is limited, I am not going to spend
it doing performance runs.
The Speed number is derived from the paddlewheel instrument in my boat
and represents speed through the water, not GPS speed over ground. So
this should compensate somewhat for the lack of there-and-back
averaging. The numbers here are averaged across all the data points
that I did collect.
Hopefully the above table won't be mangled on display.

Current (A) 30.00 45.20 82.00
Voltage (V) 51.80 51.40 50.90
Power (W) 1524 2389 4172
Speed (kts) 4.70 5.10 5.90
Cap. (Hr) 2.61 1.66 0.95
"Range(nm) 12.26 8.49 5.62

My system is an Electroprop PM20, same as Eric's conversion.
My batteries are LiFePO4, same as Eric's, but the capacity is 100Ah
instead of his 160Ah.
My prop is a 12x14 3-blade instead of his 4-blade.
My boat is about the same size as Eric's, but 1 ton lighter (8000lbs vs
about 10,000 for Eric's)
My boat has a deep fin keel and prop strut as compared to Eric's full
keel and aperture prop.
Eric uses a dripless shaft seal whereas my boat uses the GTU packing in
my old stuffing box.
So, where my boat should slip easier through the water, having lower
wetted surface and lower displacement, I have a less efficient prop and
more friction in the driveline than Eric's boat.

That said, my numbers are about 2% better than Eric's, which more than
meets my expectations. I am extremely happy with the conversion and its
performance to this point.
I sized the pack to my relatively small lake. With this pack and this
performance, there is nowhere I can't go on this lake, and return home
successfully. Passing through the locks and into the seaway and
neighbouring lakes will require that I bring my portable 2000W gas
generator, which I would bring anyway for extended cruising.

Performance of the drive compared to my old one cylinder diesel is night
and day. With the old diesel being a horizontal cylinder, the vibration
was intense and it hit a couple of harmonics with the engine mounts
which prevented me from either idling at lower RPMs or staying very long
at a comfortable cruising RPM. With the electric, I can go smoothly at
any desired speed and also hit my 90% of hull speed (6.7kts) at full
throttle. I never did that with the YSB8. Motoring at 6kts at around
80A, the stern wave fills in nicely and the boat moves. And yet, we can
continue to converse quietly in the cockpit. My 3 year old son loves it
as well and is now asking why other boats are so loud and when they will
get a nice motor like Fugu.

Charging the batteries is great. The lithium cells are now in perfect
balance and it is the charger that finishes its cycle and shuts off on
its own as opposed to the BMS seeing a cell go high and cut off the
charger. I am using the miniBMS from CleanPower Auto, which I purchased
through my battery vendor, Canadian Electric Vehicles, along with my
Elcon charger. I still don't like to leave the boat while the charger
is connected, but that's ok since lithiums don't mind sitting partially
discharged for days at a time. This does require that I head to the
boat a couple of hours before leaving the dock in order to top up the
bank. But time on a boat is never wasted. I must say that lithium
batteries are more than worth their increased upfront cost. They
perfectly match the use (and abuse?) cycle of electric boating.

On the electrical installation side of things, I decided to keep all
voltages separate. My cockpit locker (port side) houses the AC system
from the shore power inlet, to the AC panel, galley counter GFI outlet
(only one on the boat) and the battery charger. The cable from the
shore power plug to the panel has been routed through plastic electrical
conduit. The 48VDC charger output is also routed to the 48V DC panel in
electrical conduit. The AC wiring is protected from contact from
shifting of items in the locker as well as possible water ingress,
should there ever be a leak. The AC panel breakers and galley GFI
outlet are on the other side of the cockpit locker bulkhead. To check
the charger status, I can just open the cockpit locker and see the
status LED on it.
The 48V electrics are all located on a piece of plywood in the engine
compartment behind the companionway steps, along with 2 double-pole 48V
breakers, a 30A for the charger DC output and a 10A for the 300W 48V-12V
converter input. Everything that runs at 48V that isn't a battery or
motor or charger is on this board, from the class T battery fuse to the
contactor to the BMS and SoC meter and motor controller. There are not
exposed terminals anywhere. This is important when you have a curious 3
year old and you plan to go cruising for a few weeks at a time...
Accidental contact with diesel or motor oil is icky. Accidental contact
with a lithium battery pack can have other consequences... The breakers
are simply off the shelf DC DC breakers available at West Marine. The
Blue Seas breakers for 12V marine systems are made by Carling and are
good for up to 60VDC. My system voltage never rises to 60V, even at the
highest charging output. My panel is just my recycled 5-slot panel from
my old 12V system. A new 8-slot breaker panel is going to be on the 12V
side.
This brings us to the 12V side of things. My old 12V setup had the
batteries and heavy gauge cabling done inside the starboard storage
compartment under the navigator's berth. At the center of this is a
OFF-ON-BOTH mini-switch which handled connecting both house and engine
start batteries, along with a shunt for monitoring house loads and the
feed-wires for the 12VDC panel and distribution over the nav-desk.
Since I no longer need an engine start battery, and my house loads are
running off a 48V-12V converter, I don't have much going on in here
anymore. I decided to still use the mini-switch, but I may add in a
fixed 12V house battery and then a charging circuit to top it up off the
DCDC converter. That way I can completely shut down the 48V battery
bank and still have a 12V house bank running things.

I have about 2 weekends left, 3 if I push it before I haul out for the
winter. But my overall impression can be summed up by the somewhat
ridiculous happy-grin on my face whenever I board Fugu.

Originally, I thought I was up for handling the conversion entirely on
my own. But after this summer, I am coming away with a new appreciation
of what it is the vendors provide. To my mind, it is more than worth
the (supposed) extra money over the cost of the simple materials. In my
project, I used basically two vendors. First and foremost is James
Lambden at Electroprop (electroprop.com). Even though we have never met
face to face and live on opposite sides of the continent, he has proven
to be very responsive to my periodic barrages of questions. This list
has also been a valuable resource, but when you have some very specific
questions about your specific throttle or controller or integrating some
other components, it's reassuring to have an authoritative source of
information. The other vendor was Randy Holmquist of Canadian Electric
Vehicles (canev.com). He supplied me with the power delivery components
-- batteries, BMS, SoC meter, charger. The big benefit from dealing
with him was on the battery shipping. since he was also in Canada, the
shipping rate was much lower since there was no border crossing to deal
with. He also was able to ensure that each component was correctly
ordered and configured to work with my batteries -- a kind of sanity
check, if you will. Different suppliers' lithium chemistries have
different charge profiles. Even within LiFePO4. So setting the charger
profile requires knowing which cells (to the model number). The BMS is
a little simpler, but there is still a list of voltage thresholds to
declare at order time. Randy made sure that everything made sense.
Also, his prices were quite good, especially once shipping was factored
in.

As I said earlier, I originally though I could take the whole project on
myself. I am sure I could have. I have the knowledge. I have the
ability. I don't have the time. As it stands, this project is still
ongoing. Even having gone though vendors, I found I still had more than
enough on my plate to both keep me busy and satisfy my tinker's spirit.
Everything from prepping the engine room, fitting everything, dealing
with the surprises that always pop up, building the throttle box,
routing the cabling, planning the layout of everything... There is a
lot to do. Why add in things like engineering a new, unique mounting
system for your motor and transmission, and controller programming,
motor characterization, prop selection, etc. The vendors do all this
stuff all the time. Dealing with a vendor also gives you access to
knowledgeable experts that are willing to talk to you, to help you.
That is what you are paying for when you go with a vendor. I certainly
took full advantage and I feel it was worth every penny.

Ok, enough proselytizing. Electric good. Boat amazing. Skipper happy.
There it is.

Cheers,

/Jason

--
Jason Taylor
--
S/V Fugu
1978 Beneteau First 30
Electroprop PM-20