(By Jeff Southern)
November, 2001 (Last Updated on 11/25/2003 )
2002 Phelix Bass Boat with electric Drive Installed
I built a new outboard from a Briggs & Stratton 5hp Gas engine and one of their E-Tek 48V electric motors. I also built one for my dad. This motor will push my boat along at 6.5mph with a 75amp draw. At 40amps, it will push the boat about 5mph. Briggs & Stratton will be introducing an electric outboard similar to this one in the near future.
I removed the original cover plate and fabricated this hatch cover with a hinged lid and a gasket seal. This make a great little dry storage box to hold some small items. You can also see how the front seat base is laminated to the stringer system.
I made a new set of rod holders out of polyethelyne and Aluminum. I really like the way the bungee straps secure the rods and yyet are easy to remove. I put a set of these on each side of the boat so that I can secure up to eight rods. I put a little carpet on the front aluminum offset plates so that the reels would not rub the plate. The top two positions clear the rear bench seat so you can have two rods on each side up to eight feet long. The top rod in the photo is a 7-1/2' flipping stick.
Here is a close up photo of the front rod holder with the offset mounting bracket.
I spent the summer working on an electric drive fishing boat. I wanted to design a boat to fish electric motor only lakes that would be comfortable and practical. I never realized how difficult putting together an efficient all electric drive package can be. The hard part is finding a suitable boat. Displacement and Planning type hulls are the two primary type of boat hulls.
A displacement hull is a hull designed to run at speed with a significant part of the hull in the water. The advantage of this type of hull is that it requires relatively small amounts of power to propel it through the water. This type of hull is also suitable to carrying heavy loads with little loss of performance. The main disadvantage is that speed of most displacement hulls is limited to between 8 - 25 mph. Any speed over 10 mph is primarily limited to large ships. The hull speed of a displacement hull is primarily determined by it's length. The longer the boat is relative to it's beam, the faster it will go. A canoe or kayak is a highly efficient small displacement hull, but is not all that comfortable to fish from.
A planning hull is a hull that is designed to lift the boat hull up out of the water and basically skip across the surface. This type of hull can produce drastically higher top speeds. The only disadvantage to this type of hull is that it takes a huge amount of energy to lift the boat out of the water and hold in on the plane. While a planing hull would probably be preferable to most bass fishermen, it is not practical to at this time to plane a boat with an electrical motor. In short, there is not enough reserve electrical energy in current battery technology to plane a boat for any significant amount of time. Planning boats are also quite sensitive to weight. The weight of additional batteries to increase range, would be a self defeating proposition because you would need an ever increasing amount of power to plane the boat with an ever increasing weight of batteries. There is some hope for fuel cell technology, but it is still many years off. Therefore, any realistic electric drive fishing boat is going to run in displacement mode and be powered by batteries in the near future.
Unfortunately, I was unable to find anyone who manufactures a displacement hull boat that would be suitable for bass fishing. As a result I had to chose a boat that was designed to plane as a displacement hull. This is simply inefficient. A narrow boat like a canoe allows the bow to separate the water and slowly taper back together at the stern without causing much turbulence. One the other hand, the square and flat transom on planning hull creates a hugh eddy current when run as a displacement hull. You are literally dragging hundreds of pounds of water behind you all the time. As speed increases, the drag goes up exponentially. The only problem with a canoe type hull is stability. If you stand up, there is a significant chance that you are going to get wet. This limits the speed of most fishing boat hulls to about 4-10 mph when powered my an electric motor. An aluminum john boats are often used as electric drive boats with 24v trolling motors as the primary power source. These work well, but are not as comfortable as other types of boats.
This is, however, not all bad news. A boat that will run 6mph is quite practical on a lake of less than say 1000 acres. Many lakes of this size either limit boats to about 10 hp or only allow electric motors to operate on them. I find that these lakes are great in the late spring and summer when the Ski Boats, Jet Skis, and pleasure boaters take over the larger lakes. It is just not much fun to try and fish with all of this activity. The restricted water ways are a welcome change this time of year. Also, most of these lakes receive less fishing pressure and can be quite productive.
My first thoughts on a boat was to build a platform between two canoe hulls to make a small catamaran. I was going to seal the canoes and fill most of the space with expanding foam to provide for safety flotation. I even posted a message with a rough design sketch to get some feed back from others. Rick Peirce from Bass Cat saw my post and sent me an email about a new small fishing boat they were in the process of designing. The boat was a narrow beam shallow draft fishing boat that seemed like it might work well in my application. After seeing the design of the boat which is called the Phelix, I thought that it would operate reasonably efficiently as a displacement hull. The thing that I liked about the Phelix is that seemed to be a good compromise between displacement hull efficiency and stability. The boat is designed to run as a plaining hull with a 25 hp gasoline engine. In fact, it performs quite well with the gas engine. I had the opportunity to drive one and it runs with a top speed of around 30 mph and handles quite well. The shallow draft and narrow beam of the boat meant that the transom drag , for lack of a better term, would be minimal.
The layout of the boat for fishing is quite good. It has a small front casting deck with a built in ice cooler. I especially like the molded in non-skid surface on the decks. It is easy to maintain. The cooler can be made into a live well, but I prefer to use it as a cooler. There is a dry storage box under the bow. I installed the front and rear fishing seats which I purchased from Cabelas. I did order the front seat base from Bass Cat. This base is mounted with a combination of bolts and fiberglass work. There is a sub structure under the deck that ties the seat into the stringer system of the hull. Unless you are comfortable doing fiberglass work, I suggest that at a minimum, you have the seat bases put in when you order the boat.
I liked that fact that each side of the boat has a raised rib that is the perfect place to mount some rod holders. The ones that I mounted are made by Rod Saver and have a molded foam insert surrounded by a nylon strap. I had to make some aluminum clips to mount them as the ones that were supplied by Rod Saver will too wide. I put a screw through the clip and the nylon strap into the rib. Once I mounted the straps, I glued the foam into place using some Marine Goop. There is one set on each side of the boat and each set can hold up to six rods, but three is more practical.
The center console contains a livewell and small dry storage box. The little storage box is the best place in the boat to put something that you want to keep dry.
The built in rear bench seat has a small rigging area under it to put a few items although it is hard to get them out. You need to install at least two seat bases if you want to have a seat in the rear. The one off to the side is used to drive the boat and the other in the center to fish from. This allows your passenger to sit on the other side of the bench when running. However, the weight is balanced better if the passenger sits on the center console. However, at only 5-6 mph with the electric drive, the passenger can simply sit in the front fishing seat.
The rigging area is large enough to hold four group 27 batteries, a triple bank charger and the motor speed controller. This adds up to about 235 lb and is about as much weight as could safely be put in this area. The best choice of batteries to power an electric boat are 6v golf cart batteries. However, you would need 6 of them wired in series to get up to 36 vdc. They typically weigh about 60 lb each and six of them would not fit in the rigging area. In addition, you would need one additional 12v battery to drive the electronics and front trolling motor. This would put the battery weight up to 415 lb.
After selecting the boat, the next problem was the main drive motor. I first tried a 54 lb 12v Transom mount trolling motor. This motor could only push the boat about 3.5 mph on high. It became obvious that the plastic props on trolling motors are not ideal for uses as a primary drive system. These props are designed to quickly accelerate the boat is short maneuvers. You could try a large 24v or 36v trolling motor or multiple 12v trolling motors. I have a friend who runs an electric boat with three 50lb 12v motors with good results. An after market aluminum prop may increase the top speed a mph or two, but you should know that these props cause the motor to pull more amps that the windings were designed for and could over heat the motor and severally damage it. The trick would be to run the motor at full speed and measure the amp draw with the plastic prop. Then add the aluminum prop and test the amp draw again. If the amp draw is too high ( say more than 5 amps higher ), keep cutting the diameter of the aluminum prop down until the same amp draw is reached. A small metal lathe would be ideal to cut the prop diameter down. You can often have this done for free or at a modest fee at a local traid school.
Electric Outboard Manufactures
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There are several manufactures who build electric outboard motors. However, I found them to be quite expensive. The cheapest was about $2,500. The most expensive was over $4,000.00. Since I own a machine shop, ( and like to tinker with stuff ), I decided to build my own motor by converting a small gas outboard to electric drive.
I bought a 2.5 hp Nissan motor and removed the power head. I chose the Nissan because it is light weight, has a simple one direction gear box, a fairly low gear ratio of 1.85:1, can be shipped via UPS and can be purchased on-line. The total weight of the converted outboard was only 23lb. I installed a Scott 24v 1 hp motor on the outboard using an adapter plate that I fabricated from aluminum tubing and 1/2" plate. The drive shaft in the Nissan is a piece of square stainless steel tubing. I had to make a fairly complex coupling to adapt the round shaft of the motor to the square drive shaft. In hind sight, it would have been easier to shorten the shaft and weld a round shaft into it to match the motor shaft. The motor is controlled by a 12-36v PWM variable speed controller with a motorcycle style twist grip pot. I replaced the stock 6" pitch prop with an optional 7" pitch prop. The electric motor generates it's HP and a much lower rpm than the original 2 stroke power head. Even though the motor is rated for 24 vdc, I run the motor at up to 36 vdc. This will inevitably cause the motor to heat up if run at full power for a period of time longer than 15 min. If the motor is run at around 50 amps it does not heat up much. At full power, the motor is putting out about 2.5 - 3 hp. It will push the Phelix fully loaded with two people about 6 mph and draw about 80 amps. I recently added a Kort Nozzle to the outboard to improve efficiency. The results were not as much as I had hoped for. However it did increase the top speed by about 1/2 mph and it reduced the current draw at the top speed by a solid 5 amps. I made the nozzle from sheet aluminum that I rolled and welded into shape. As a result, it is not prefectly round and may explain why the efficiency was not much improved.
The three Group 27 AC Delco batteries will supply this much current for about 50 minutes of operation. The motor is more efficient at 50 amps and will push the boat about 5 mph for about 1-1/2 hours. At 25 amps it will push the boat at about 3.5 mph for about 2.5 hours. This may not seem like much range, but on a small lake it is plenty of speed and range. The forth battery is used to drive the 12v 54 lb trolling on the bow. This is a Motorguide Excel motor. It is a power steer foot operated version. I chose this motor because I got a good deal on it and because I can control the motor while sitting on the center console. This is useful for maneuvering while changing baits. I should note that I would have purchased a simple cable steer unit if I had not recieved shuch a good deal on the motor as the power steering is not really a big improvement over the cable steering.
I recently purchased a 25 hp Yamaha four Stroke gas engine to use on the boat when I want to fish larger lakes or rivers. Being a tiller handle boat, it is fairly simple to convert the boat over from gas to electric drive. It takes about 15-30 minutes to make the conversion. This makes this boat very versatile. It can be used in just about any fishing situations. The more I use this boat, the more I like it. It is easy to handle with one person. I installed a Hamby Light Duty beaching bumper to make loading and unloading the boat a simple task even for one person. You can click this link to read an atricle I wrote about installing the Hamby. This boat is inexpensive to operate and tow. It is stable enough to fish in all but the worst weather conditions. It's shallow draft and narrow beam let you easily maneuver into areas that would not be suitable for larger boats. I don't know if I would like to fish tournaments from this type of boat, but it is ideally suited to a relaxing day of fishing for the pure fun of it.
The results of my test with the electric boat are fairly straight forward. You can have a very enjoyable day fishing from and electric powered boat. You have to use a little common sense and not try to fish areas where you would have to run long distances to get to and from the fishing holes. While the boat is best suited to the 200 - 1000 acre lakes, it also works well on larger lakes if you adjust your fishing habits. I have fished Allatoona and Lake Weiss with the boat by launching the boat in a creek or other narrow area of the lake. In short, I started in the area I wanted to fish. Using a combination of the Main motor and the trolling motor, I have fished as many as 15 miles of shore line in a single day. If there is any significant wind, I use the electric outboard to drive me up wind and drift fish back letting the wind push the boat and only using the trolling motor to control position. This conserves power and extends the range considerably on a windy day.
Specifications and cost of this various components that went into the original project.
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