E-Pod 3000+ Electric Drive Conversion Observations
Overall the conversion process went fairly smoothly considering we removed over 1000 pounds of gear and added back about the same 1000 pounds in batteries and electric drives. In all it took about two full weeks working time (with two people working together during most of that time) spread out over about 4 weeks due to other commitments and waiting for various parts to arrive. The activities that I thought would be the most problematic were actually easy. The removal of the drive leg and engine in all took about 8 hours time with two people working.
Surprisingly the new water system installation which should have been easy took considerable time and effort due to issues with the Excell instant on water heater refusing to work and wasting almost 8 hours of precious working time over an afternoon and morning.
Is it worth doing?
I guess the most telling question to answer is now that I have done it, is “Would I do it again now that you know what it takes?”
The answer to this question at this point is Yes and No. Definitely Yes to removing the diesel and outdrive; and Yes to installing the Outboard. The jury is still out on the e-pods.
The e-pod technology is clearly behind the outboard as far as being perfected but still working for me given the limit way I use them for low speed maneuvering; and still as step above the diesel/outdrive solution. The Honda Outboard is the optimum technology for powering a boat and once the e-pod drives reach end of life or have any problems, I will most likely remove them and depend solely on the outboard as the main source of power. This will remove over a 1000lbs of weight from the boat mostly in the form of batteries making it faster under sail and about to carry much more load if necessary for cruising. I will install a second outboard mounting block on the stern step of one of the hulls to allow the smaller 2hp Honda (used for the dingy) to be available as a kicker in situations where the outboard fails to limp home with. Eventually I will get a larger dingy and upgrade to a 8 or 9hp outboard (or bigger; 15hp would be my dream) and then have a kicker that is more up to the job.
Had I not made the conversion, I would never have removed the tanks from inside nor believed that a 15hp outboard is sufficient to power the boat...so it was worth doing to get rid of the diesel and drive leg and all there associated problems....so overall I am much happier. Perhaps in the mean time the e-pods or another electric drive technology will be perfected that I can use. I hope my effort here in someway furthers that evolution as there are some really great benefits to the system for low speed maneuvering.
The best and worst thing:
What are the best and worst things about the e-pods?
(Disclaimer: This is purely my subjective assessment based on my experience with a single installation on a single boat over a very short time so take what I say in context and keep in mind I am a strong supporter of the technology and should be considered biased. With that in mind, do not blame me if you decide to convert like I did and don’t have similar results.)
1. Having instant power available when you miss a tack or when in close quarters for maneuvering. The old drive leg was always an issue to drop into position and warm up the engine before you could go anywhere. When you are staring down a tanker and the wind has suddenly deserted you is just no fun. Also the redundancy really allows me to relax when motoring into a marina or sailing a narrow channel in light winds. Knowing that any one of the three 15hp engines will get you safely to the dock is comforting compared to relying on the single diesel/drive leg combo with all of its well documented potential points of failure. Consider during our longest trip from Richmond’s Marina Bay to Benicia Marina (about 18 miles) which turned out to be mostly motoring due to lack of wind we had the outboard run out of gas after 15 miles on the first tank which had about 2 gallons in it when we started (I only carry two 3 gallon tanks). Normally when you lose power there is a bit of excitement; but as soon as the outboard stopped the two e-pods continued pushing the boat at over 3 knots drawing less than 10 amps without the outboard running so you did not even get concerned at all about it; we just enjoyed the silence for a while. I simply connected the outboard to the second tank and restart it which took about two minutes since I was in no hurry; with the outboard again at half throttle we were back to 6.5 knots and the e-pods drawing less than 3 amps (never touched the controls for the e-pods).
2. Another great thing is the speed; she is faster under power now. Without pushing the e-pods more than 3 amps and outboard at half throttle we were moving at between 6.2 and 7 knots which is better than I did with the diesel which seemed most happy at 5.8 knots although she would break 6 knots if you pushed it hard. Part of this is due to the boat being lighter. Although based on my calculations the boat should weigh about the same; but the way she sits in the water tells a different story; about an inch higher at the stern and 4 inches higher at the bow. My feeling is that the Westerbeke engine is a lot heavier than advertised based on how it felt coming out; plus and a lot of little items like heater hoses, fuel lines, filters, tanks, wiring harnesses, control cables, etc add up more than you would expect. Also getting rid of the water under the water tanks helps but hardly accounts for the great change in the way she floats; so I have no explanation for the change but I am delighted with it none the less. Certainly the hull had over a week on the hard to dry out which helped as well.
3. Light wind sailing was a pleasure for once. Typically the Gemini is not great in light winds due to her low aspect sail plan and small control surfaces ineffectiveness at slow speeds. However with the e-pods providing just a little push (5 amps) the boat was able to create its own wind to keep the sails pulling and the boat moving. The e-pods providing enough water flow over the rudders to allow you to steer. We sailed past the bow of a 40 foot mono who was hardly moving at maybe 1 knot mostly due to the tide; they were greatly impressed with our speed under sail; they had no idea there was anything helping us along as the outboard was clearly off and up out of the water at the time. With only a breath of wind she was doing between 2-3 knots; just enough to keep me from resorting to the outboard. Keep in mind that this was with 14 people aboard so the boat was heavy and we had been expecting normal heavy summer winds and thus were using the small 100% heavy working jib and full mainsail; not at all the right setup for light winds so the speed was even more impressive given these facts. I am definitely more likely to sail more or should I say motor-sail with the e-pods.
4. The boat stability has improved as a result of the conversion moving the weight down lower and out into the hulls. It was completely unexpected but as we used the boat more and more, I noticed a significant change. The boat was less prone to throw the mainsail around in washing machine conditions in light winds which we often run into on the SF bay in the lee of Angel Island due to the strong currents there. Considering we took and engine (300lbs) drive leg (110lbs) and fuel tanks (300lbs) and removed them adding only a 136 pound outboard (which is down fairly low on the bracket) in their place much of the weight up high in the center of the boat was gone. The majority of the weight for the install was all down under the bunks in the form of batteries at the water line level. The result of this change could easily be felt; she was less inclined to roll which is a great improvement. Also the pitching was reduced since the weight sits at the boats pivot point and allows the bow to more easily move up and over waves more quickly. Moving the weight to the keels center pivot point, down low is a standard practice in racing monos to make them faster, more stable and handle conditions better; so I guess it should really be no surprise. Another benefit of moving the weight down low and outward into the hulls is the boat is more resistant to capsize, which is always a concern in a narrow cat that has to contend with high winds common on SF Bay.
The every present low hum of the electric e-pod motors takes a little getting use to. After a while I forgot it was even there at times (but you would pick up instantly on any change in sound due to increased speed or fowling which I think is good in many ways; giving you instant feedback if anything is wrong); most on board never noticed and thought it was a normal sailing sound. I think this is because you get use to such a low level of sound while sailing that any noise would be noticed when you are skipper sailing the boat. The Honda 15 outboard (although it is far quieter than the Westerbeke) seemed like such a loud engine compared to the e-pods that you were grateful whenever it was shut off. Guess any noise is an issue compared to silence of sailing without noise at all. Once installed, the e-pods will always be turning when the boat is underway and you will always have a low hum from them which increases as you switch from pushing the boat to generating power from them.
Other observations of interest:
1. The e-pods produce much more thrust than estimated. At 10 amps on flat water and no wind they would push the boat at about 3.7 knots; with 12 people aboard against 15 knots headwind on flat water in the marina 20 amps pushed us at 2.2 knots. To go faster than this I would normally start the outboard; just did not make sense to push the e-pods harder than that as the increase for example of 10 amps only added about a half knot of speed; so burning twice the power to go just a little faster did not seem worth it….but I think I was really conservative with preserving power for getting back in should it be needed, after all it is still new to me and would take some time to get use to measuring fuel in volts and amps rather than simply in gallons. Docking is the only time I used more power than 20 amps on the e-pods. When stopping the boat quickly, I would push them up to 30-40 amps for a few seconds only.
On one occasion, I was a bit concerned coming into the dock with a 25-30 knot tail wind pushing us fast towards our downwind berth. With the outboard off and dragging to slow us down and e-pods engines both at less than 1 amp, we were still moving at 2.5 knots as we approached. I did not want to reverse too early as this would reduce my control which requires good boat speed at this wind speed making things interesting when you are trying to fit a 14 foot wide boat into a 16 foot wide berth. As the bow entered the berth, I began backing down gradually increasing power and was able to stop the boat in about half a boat length well before the end of the 45 foot slip. Given there were 12 people on board that day the boat was not light either and I am thankful for the extra power the e-pods offer. I know I would have been backing the Westerbeke diesel/drive leg combo down at max thrust to stop on that day, no doubt; just considering that the latch holding the drive leg down may not hold makes me cringe…the e-pod solution gives me considerable peace of mind in comparison.
Given there considerable power (over 15hp each), I doubt I will have any concern about entering most any docking situation with them in the future. For example in Benicia marina, with the e-pods we turned the boat around 360 degrees in area about 10 feet wider than the boat is long and put her along the guest dock with little effort in spite of the 15 knot wind blowing me away from it. I remember the difficulty I had doing this exact same maneuver there 6 years ago with old diesel/drive leg power combination; it was not fun as I was new to the boat (first trip) and we were very tired at the time after sailing all day form Alameda to get there. It seemed like it took hours although I am sure it was no more than 15 minutes and a dozen tries to put her along the dock. Back then being use to racing monohulls with deep keels, I just did not get how much speed is required to maneuver a light cat with lots of windage in close to a windward dock; and was really reluctant to hit the dock with my new boat as well. I learned that day the only easy way to do it was to go straight at the dock with the bows and drop off a crewman with a bow line; once the bow is tied off to the dock you just turn the helm hard over and motor towards the dock until she swings around; the steerable drive leg allowed the thrust to be directed enough to push her stern in. With the e-pods it is about the same except you can easily maneuver up to the dock slowly using the twin props to steer, drop off your crew who ties off the bow spring line and then use prop walk to turn her with the starboard engine moving forward and port going astern when docking on the starboard side; absolutely painless operation.
2. The smell of combustion engines is missing when running under e-pods and you don’t notice that it is gone until you pass another boat under power. I always like to start the up the outboard at the dock just to make sure it runs before we leave, but the second I smell it I remembered what the diesel smell was like during the 10 minutes waiting for the diesel to hit operating temperature. I always turned the outboard back off after letting it run for about a minute since leaving the dock was always done on e-pods alone. Normally, I did not start the outboard until under way and only use it for going forward so you do not catch the smell of the exhaust, thankfully. To date, I have never used the outboard in reverse gear or during docking.
3. The e-pod engine controls are dead easy; just two small levers; up is forward, down is backwards; the further you push them the faster they run. With the diesel, I was never comfortable having the boat under anyone else’s control, but with the e-pods I found myself comfortable turning the helm over to my 16 year old son while raising or lowering the mainsail. Also, I think the fact that he could easily hear me due to the lack of noise from an engine made me more comfortable to let him take the helm during sail raising/lowering maneuvers. Not having a transmission to shift or a drive leg to steer takes a lot of worry out of the situation. At low speeds you simply steer with the motors adding/removing power to one side or the other as needed to keep her into the wind; for once maneuvering at speeds below 2 knots is easy and safe. I found that we would almost stop the boat completely during mainsail raising/lowering and face the wind in this manner; simply wonderful. This allows the maneuver to be performed in a much smaller area and we typically stayed under sail all the way back to the dock and did the drop in the marina.
4. The Honda 15 hp outboard was a great comfort as we built trust in the e-pod system. Without the Honda, I would have been reluctant to set off many days due to the excessive wind or lack of wind. But the Honda offers reserve power to cover great distances quickly without concern of depleting the batteries should if become necessary. Obviously, a genset would also offer this same benefit; but at much more cost and complexity as well as not offering nearly the redundancy of having an independent outboard available. Actually, I already do have a genset in the form of a Honda EU2000 which if required could have been setup and used to run at least one charger for the e-pods battery bank providing 40 amps continuously if required.
5. Electric tilt and electric start make the out board a pleasure to use. The motor at a touch of a button is tilted down into position. Turn the key and it starts first try almost every time. You can hardly tell it is running while it idles. It does not require time to warm up, at least I do not normally give it more than a minute before engaging it and it does not seem to mind. So in great contrast to the outdrive/diesel combo the operations of all them motors have be absolutely painless. Life is wonderful aboard again.
Although this conversion may sound pretty good from reading my comments here, it should be made clear that it was definitely not easy to do or cheap. It was hard work and if not for fellow Gemini owner, Tim McGinty, helping out especially with the leg and engine removal, I doubt I could get it all done during my 5 week vacation. Tim is extremely handy; it is rare I meet someone who is my match when it comes to working on boats; but Tim is definitely a wonder to have working with you and never hesitates to take the initiative and get it done, no matter how difficult or unpleasant the task.
The only major problem I had was after two weeks of using the e-pods, a small leak developed in the port buoyancy compartment where the port engine is mounted. Water was seeping around the mounting pipe; about a full sponge of water a day. It had 4 buckets full in it before I noticed the leak. The hoses connected to the top of the motor mounting pipes prevented damage to the engine and the water leak was contained in the compartment. After hauling the boat, I discovered that the spacer block the goes between the e-pod motor and bottom of the boat is apparently made of wood and had split allowing the engine to move up towards the boat bottom breaking the seal and allowing the leak. Clearly these blocks should have been better designed and made of something more resistant to the marine environment. But I accept that the e-pods engines are still new technology and that a few bugs are to be expected along the way. In fact, I am happy to report that this was the only problem I experienced with the e-pods.
Update: the e-pod mounting blocks have been replaced by Eagle Marine boat yard in Martinez. They used my design of 10 layers of G10 fiber-board epoxyed together to form a solid block. Holes were drilled for the mounting pipe and the space around them filled with foam to prevent the heat expanding the air and breaking the seal. The motors were remounted with 4200 sealant forming a bullet-proof connection to the hull. I believe you could easily lift the whole boat with either one of the motors making them strong enough to withstand a grounding or solid impact.