Q: How does the weight of an electric system compare?
A: Depending on battery bank selected, a 48V 100Ah powered system typically weighs less than 350 lbs. A 48V 200-250Ah system will weigh in at around 550 lb. By comparison, a typical engine, fuel, fuel tank, exhaust and other equipment might weigh in the 400 – 600 lb range.
Q: Are electric drive systems under-powered?
A: A QuieTorque TM 180ibl system has enough power to drive most boats up to 32 feet to hull speed. Typically, an electric system can replace a diesel or gas engine of twice the HP without significant loss in top speed. In many cases, customers find it acceptable to replace an ICE of 3 times the HP of the electric. The loss in top speed is more than offset by the quiet and “right now” power of an electric system.
Q: What is the range of an electric system?
A: This is a function of battery capacity, boat performance and power setting. A typical system will have 60 – 90 minutes of run time at full power. At 6.5 knots, this translates into 6.5 – 10Nm. Reduce speed to 4 – 5 knots and the power consumption drops off dramatically. Range will increase to 10 – 15Nm. Range can be extended further at lower speeds. As a rule of thumb, every 1.25 – 1.5 knot increase in speed requires a doubling of power.
Q: Can you tell me how much speed and range I will get from a system in my boat?
A: Yes– we have worked out tables that give a pretty accurate estimates of both the speed (a function of motor size) and range (a function of battery bank size). These tables are also put to use when we build your order to determine the optimum reduction ratio for teh prop you are using.
Click to our Design Page and scroll down to the form you can submit. You will receive two to four Performance Projections in a few days that will give you a pretty good idea of the speed, range and cost factors of the System and battery banks.
Q: My diesel still runs OK, is there a market for it if I want to go quiet, odor-free and Green?
A: You will be pleased to know that you may be able to fetch a price in the neighborhood of $2,000 for an operational ICE. Check your local Craig’s list and the local and national markets on eBay.
Q: How effective is regenerative charging?
A: Your propeller size and average sailing speed determine the effectiveness. Typically, it will serve as a supplement to other sources. When sailing, you can expect to supply your house power needs and will be putting power back into the batteries. Catamarans get the best results.
Q: Just how quiet is an Electric Yacht System?
A: Quiet, but not silent. Extremely quiet when compared to that chugging diesel. Some component noise is to be expected in the form of drive-line sounds when operating at the mid-throttle range and above. Unlike the diesel, though, passengers and crew can expect to talk in normal volume both in the cabin and on the deck. Very handy for foredeck communication when docking and anchoring.
If you are a racer, expect to have your competitors demand that your key be hung on the backstay in plain view to avoid any temptation to squeeze on a little tiny bit of “electric wind.”
Q: Can I install the electric motor while still in the water?
A: Yes. Our system is designed to make installation as simple and easy as possible. Since the existing shaft and propeller are used, it is not necessary to haul out to make the conversion. We will provide the right reduction ratio to match the motor’s available torque to your propeller.
Q: What maintenance is required with an electric system?
A: Very little. If you have flooded batteries, you will need to check the water level and add distilled water periodically. For the rest of the entire system, grease the output shaft bearings and inspect and clean the battery connections annually. That is about it… How does that compare to your old A-4 or diesel?