Frequently Asked Questions2019-03-19T14:44:01-06:00

Frequently Asked Questions

Are electric drive systems under-powered?2020-07-29T09:17:51-06:00

We will typically size a system with enough power to achieve hull speed.  For example, the QuietTorque 10.0 system has enough power to drive most sailboats up to 30 feet at hull speed. An electric 10 kW system can replace a diesel or gas engine of about 20HP.  Any loss in range and speed is more than offset by the Clean! Green! Quiet! and the immediate “right now” power of an electric system.


How does the weight of an electric system compare?2020-03-03T17:10:51-06:00

Depending on battery bank selected, a 48V 100Ah powered system typically weighs less than 350 lbs. A 48V 200-250Ah AGM battery system will weigh in at around 550 lb. A 48v 200-250ah LiFePO4 battery system will weigh in at around 350lbs. By comparison, a typical engine, fuel, fuel tank, exhaust and other equipment might weigh in the 400 – 600 lb range.

What maintenance is required with an electric system?2020-07-29T09:10:00-06:00

Very little. The QuietTorque system is practically maintenance free.  LiFePO4 and AGM batteries do not require maintenance.  Flooded batteries require maintaining water level and add distilled water periodically. Check terminals and keep them clean with no loose connections.  For the rest of the system, grease the two thrust bearings one a year.   That is about it… How does that compare to your old A-4 or diesel?

Can I install the electric motor while still in the water?2020-07-29T09:11:27-06:00

Yes.  The QuietTorque systems are designed for easy installation. It is not necessary to haul out to make the conversion. The smaller units are less than 60lbs and the mid-range systems are about 130lbs.  The larger liquid cooled systems  to 180 to 220lbs and you would be wise to do them out of the water as you would want to upgrade the through hulls at the same time.  Most systems use the existing shaft and propeller.  You may wish to have the shaft, packing gland, and cutlass bearing checked and replaced if worn.  We will provide the right reduction ratio to match the motor’s available torque to your propeller.

Just how quiet is an Electric Yacht System?2020-07-29T09:12:28-06:00

Quiet, but not silent. The QuietTorque system is very quiet when compared to a diesel. Some noise is to be expected in the form of drive-line sounds when operating at the mid-throttle range and above. You will hear your underwater drive train.  Hearing your cutlass bearing and propeller will be a new experience.  Unlike the diesel, you, crew, and passengers can expect to talk in normal volume both in the cabin and on 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.”

How effective is regenerative charging?2020-07-29T09:13:14-06:00

The QuietTorque  systems all have native regeneration.  Your propeller size and  sailing speed determine the how much power you will generate. Expect regeneration to start at about 5kts and become bankable at above 6kts.  Typically, it will serve as a supplement to other sources such as solar. 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.

My diesel still runs OK, is there a market for it if I want to go quiet, odor-free and Green?2020-07-29T09:14:15-06:00

There will always be a market for running diesels.  As long as you can turn it over, there is a market. It is common to see running diesels get upward of $2,000.  Check your local Craig’s list and the local and national markets on eBay.  You may also find that a local diesel mechanic will take the old diesel off your hands, removing the system and even giving you a few dollars.

Can you tell me how much speed and range I will get from a system in my boat?2020-03-03T18:53:29-06:00

Yes.   We prepare detailed motor details and provide both the speed (a function of motor size) and range (a function of battery bank size) for your boat. We share what the QuietTorque system can do and also tell you the limits.

Click to our Design Page and scroll down to the form you can submit. You will normally receive a Performance Projections within 24hrs (sometime faster and occasionally slower).  We want you to know what your options are and what limitations may exist.

What is the range of an electric system?2020-07-29T09:16:18-06:00

This is a function of battery capacity, boat performance and power setting. A typical QuietTorque system will have approx. 60 minutes of run time at full power.  If you use the sizing model of replacing the diesel with an equal powered QuietTorque  system and match the weight of the old motor, fuel tank, fuel, starter battery, and exhaust system, you will see about 15 to 20 NM range under battery power alone.  Go slow and go long, Go Fast and you severely limit your range. As a rule of thumb, every 1.0 – 1.5 knot increase in speed requires a doubling of power.

Questions? We have answers