In late March of 2014, with the completion of the Electroprop website questionnaire and follow-up discussions with James Lambden covering the specs and characteristics of my vessel and what options were available for to me to consider, we settled on their E-7 model with its 7 KW max and 5 KW continuous power rating to be run off a 48 volt battery system. It was predicted that with my 29 ft fin keel sailboat with a displacement of 7,600 lbs (in reality, probably about 8,200 lbs wet) I should get close to 5.0 knots maximum speed or about 90% of the theoretical hull speed of a boat. (theoretical hull speed for displacement vessels = 1.34 X (Sq Root of LWL) where LWL is the length of the waterline of your boat).
The E-7 has an efficient reduction drive unit inline with the motor shaft together with a flexible coupling with an alignment indicator. The motor itself comes bolted to a customized drop-in aluminum pan complete with motor mounts. After providing them with the appropriate measurements, Electroprop customized the pan to fit into my existing motor bed stringers and in alignment with my propeller shaft. They provide instructions and diagrams to assist with taking the required measurments.
To improve overall performance of the new electric drive on Chiquita, it was recommended I might want to replace my existing 2 blade propeller and get a 3 blade x 14 inch diameter fixed blade propeller to improve efficiency of the electric drive. But, as explained in the previous post, I was not yet ready to give up the low drag efficiency of my feathering 2 blade variable pitch propeller while I still race the boat in club and area regattas.
As we continued to discuss through the spring the parameters and merits of conversion to an electric drive system, the next suggestion was to possibly replace my thru hull packing gland on the propeller shaft with a PYI drip-less model in order to reduce friction against the shaft.
That was not a problem for me as I always hated the fact that the existing gland unit had a designed interval … drip … drip…drip… which left stained water marks as it drained and never allowed me to have a completely dry bilge.
A further option suggested to improve drive train efficiency was to replace the cutlass bearing if it was at all aged and worn.
Mine was a little wobbly and worn after 16 years, so off she came.
Electroprop systems come with matched controller, contactor, 48V DC to 12V DC converter, Clearview Display, TBS battery monitor, dual bank battery switch, keyed ignition and a pre-wired harness system for connecting all the components. I decided I would make the battery cables and do the distribution panel wiring myself as I had successfully rewired (with a little help from my friend Moe) the Atomic 4 seven years earlier. Once the components were mounted and batteries installed, it was plug and play.
Having researched several references, my next task was to decide what type of battery system I might choose. It was appropriately suggested for safety reasons, the choices were limited to either sealed AGM’s or LIPO4 batteries having as large amp capacity as one might afford. It was strongly advised that flooded lead acid batteries were not suitable for electric drives due to potential gassing of hydrogen (explosive) when charging, particularly if over charged, and otherwise, such gassing is corrosive to all rubber hoses or membranes in the engine compartment (such as the new PYI dripless thru hull unit that had been ordered).
Lithium ion battery features although making significant advancements in electric car proplusion technology are still a little pricing for my budget. After much deliberation, I chose a high end, large capacity TPPL AGM battery – namely, a 20 hr, 215 amp, 12 volt Odyssey PC1800-FT model as I didn’t want available power to be a limiting factor in the performance of my new electric drive. The TPPL models are noted to be accepting of a high rate of current shortening the time required to charge and can more readily recover being discharged well below the suggested maximum 50% discharge level for flooded lead acid batteries without significantly impacting its working life. TPPL’s under proper care, are touted by manufacturers to last between 8 to 10 years. Thin Plate Pure Lead batteries draw part of their superior performance being made from almost pure virgin lead. AGM’s, and this Oddessy model in particular, have the advantage they will function standing straight up, on their side, or on their back, giving more options for securing placement within the boat’s already premium storage availability.
Any major upgrade requires a boater to analyize their energy requirements. Mine was no different. Although a little hesitant at first, I accepted James’ recommendation that since I wasn’t running other large energy drawing accessories like fridge, air conditioner or water heater, I certainly didn’t need to keep a separate 12 volt house system. I could convert from 48 down to 12 volts and run the house and navigation systems as before. My hesitancy was wanting perhaps a little redundancy if somehow something didn’t work with the 48 volt system. In the end I’m glad I didn’t. It would have required a different charging system and monitors. Through the first sailing season I have had no call to need a backup. With the “1 & 2 & both” battery switch, I can choose independently to have just the 12, or the 48 volt, or both depending on my electric power needs.
Other options I chose were a new electrical panel with several features including double pole breakers on 48 volt circuits. With a higher voltage system, if a short were to occur, a double pole breaker will immediatley shut down current flow in both directions of the positive and negative feeds of the electrical circuit, significantly reducing either chance of being shocked or a large heat generation of the affected connection.
A neat feature of the new distribution and breaker panel supplied by Electroprop, was the addition of two USB sockets and a 12 volt cigarette lighter type receptacle which now freed up the need to run a separate 120 volt sine wave inverter to charge cell phones, IPADs or lap tops. These have proved to be awesome add ons.
As in my initial first few years I planned to rely principally on plug in shore power for charging the 48 volt system, we elected to go with the 30 amp Elcon PFC 2000+ battery charger. It can work as a power supply running from a Honda or Yamaha 2000 generator for those few but possible extended periods of motoring I might encounter when off cruising down Northumberland Strait. Thinking down the road a little ways and with James’ suggestion, to save me time and effort, I augmented the Elcon charger with two (2x) ProSport 20 ProMariner Dual Bank chargers. What they add was the ability to charge each of the 4 batteries independtly thus insuring all four batteries in the bank are kept balanced with periodic charging via the ProSport units.
Models, such as the ProSport 20, in addition to having the capacity to properly charge the higher end AGM’s have the ability to charge two batteries hooked up in series separately with the ability to direct more amps to a weaker battery until it is brought up to the same charge as the second one – critical to longevity of the batteries in the bank. The experts will tell you – allowing one battery to discharge and operate at a lower voltage than the others in the bank, will draw them all down and very likely significantly shorten the life span of all the batteries. Eventually, and not too far off, when the market supply catches up, one will likely be able to purchase a single – four (4) battery bank charger and avoid the duplications I have done.
On the issue of AC power in Chiquita, James suggested in my case, that unless I put in an isolation transformer at the shore power receptacle, I should not have, but with one exception, any shore power connected AC wiring in the boat. It’s both a boat preservation issue and a safety issue. An improperly wired neighbouring boat plugged into to shore power in close proximity while you are also plugged in, may issue stray current and even though you are properly wired, your boat will become the return path for electrical stray current and corrossion will result. Similarly, this stray current can be dangerous for swimmers if close by, particularly in fresh water. As James reminds his audiences in forums and in several articles, electricity generated from shore power will follow the path of least resistance, and in fresh water, that can be the human body. In salt water, because of the differing + and – ions, it has less resistance then fresh water, and stray current will usually dispate more readily out into the surrounding basin. He suggests an isolation transformer installed in behind the shore power plug-in is the pre-requiste safety measure for boats carrying AC wiring who use shore power as their energy source.
In any event, the only functioning AC wiring for now left on Chiquita was to wire in an AC GFCI plug receptacle so I could plug-in my battery chargers. My chosen chargers (but not all chargers) apparently perform a similar function as an isolation transformer in preventing stray current seepage, and therefore avoids the problem for my system.
An optional, but highly recommended safety component which I chose to install, was a Bender IR425-D4 ground fault monitor on my new electrical DC system. The monitor is designed to detect any weaknesses in the wiring or components of the electrical system so you can immediately attend to a problem before any badness happens . It will sound an alarm and flash if there is an unusual impedance to the flow of electricity in your DC system: eg – a loose connection, corrosion, or an internal fault in one of the operational components in the circut. Without it, if you suspect a problem you are likely left to run a tester through each and every connection and component to achieve the same result.
La piece de résitance for me was James’ offer to upgrade me to the new prototype OEM rotary dial throttle he was developing and shown in the following photos. I describe the throttle being similar to a stove top oven dial – Turn it right or left of center to either go forward or reverse. He explained that the benefit to upgrade was a finer control range of the throttle in both forward and reverse direction. Instead of a 60 degree range in either forward or reverse, I would have a 150 degree range in either direction with graded markings of “OFF, 1, 2, 3, 4 & 5 ” helping to indicate a rough measure of rpms of the motor or resultant thrust and velocity of the boat.
I was able to mount the throttle above the binnacle compass replacing an old Magellan GPS unit that had seen better days. The GPS had, in any event, been replaced with an IPAD with the Navionics app mounted under the dodger .
One of the immediate benefits I encountered with the OEM throttle was after launching in the spring. As I motored over to the mast crane to put drop in the mast, I found as I manouvered backing the boat into the crane dock, unlike with the gas engine, with separate gear and throttle shifts on eithe side of the binnacle and and myself usually twisted like a pretzel looking astern, with the new rotary throttle, I could turn around 180 degrees, face the stern, and with one hand on the dial and one on the wheel, control the steering, speed, forward and reverse of the vessel with greater confidence and suredness. The hardest part was getting use to the lack of engine noise. It was amazing I could hear the conversation of the two persons waiting to take my lines that normally would have been drowned out by the noise of previous engine.
……… next, My Electric Conversion ” The How”