Torqeedo Update

New Torqeedo Electric Motor Update.

You might remember that last April I posted the “I’ve Gone Green” addition to this blog.  Since then I’ve had several requests for additional information and photos regarding the installation and how the motor actually works.  So, here’s the update…

              

The Torqeedo model that I bought is the 2.0 Cruise Tiller model.  It is a 24-volt electric outboard motor that weighs about 40 pounds and has about 120 ft/lbs of thrust due to the big three-blade 10 X 12 propeller.  That is about the equivalent of a six to seven HP gasoline outboard.  The folks at Torqeedo rate the motor as appropriate for boats up to 6,000 pounds displacement.  With two 12-volt batteries, the total weight is about the same as my 100 pound Mercury gasoline engine and five gallons of gasoline.  However, raising and lowering the Torqeedo is much easier than the same operations with the 100 pound Merc.

The reasons for choosing this model were many... but one of the big considerations was that I could see where two 12-volt batteries could be placed in Snickerdoodle's cockpit fuel locker.   But, where would I put two more batteries if I went with a 48-volt motor???  Another consideration was the significant increase in price from the Cruise 2.0 to the Cruise 4.0.

The 24 volts are delivered by wiring, in a series, two Group 27 - 12-Volt deep cycle marine batteries.  I searched all over to find batteries with the highest amp hour rating.  The ones I chose were from NAPA.  These batteries are rated at 110 amp hours.  Other Group 27 batteries were rated as low as 90 amp hours.  The portside cockpit fuel locker on Snickerdoodle is just the right size for these two batteries.  And, installing them there was easy.  To keep the batteries charged, I bought a Professional Mariner ProSport battery charger rated for 12 or 24 volts.  The battery charger was on sale at the local West Marine store for $120 instead of the “normal” WM price of $150.  I installed the battery charger by securing it to the bulkhead between the big portside cockpit locker and the quarter berth.  This charger plugs into a regular 115-volt AC grounded outlet – Snickerdoodle is already wired for shore power, and I had previously installed one of those outlets near the companionway stairs.  So, mounting the charger on the quarter birth side of the bulkhead made sense to me.  The charger has separate wires for each battery which I led through a one-half inch hole in the bulkhead and another one-half inch hole that I drilled in the forward bulkhead in the fuel locker.  Whenever I plug into shore power, the charger automatically brings the Torqeedo’s batteries up to full charge.  From a nearly “used up” battery condition (the motor won’t run if the battery bank is at less than 18 volts), it takes about eight hours to fully charge the batteries.

BTW – Don’t rely on the brilliance of the West Marine staff for accurate information regarding battery chargers.  While standing and looking at the various models of battery chargers, the Inventory Manager for the local WM store approached me and asked if he could help.  I had the ProSport charger out of the box and asked how the charger could be changed from 12-volts to 24-volts.  He advised me that I would need to take the back cover off of the charger and move a “little wire” from a 12-volt post to a 24-volt post inside the charger.  This seemed odd to me… but the price was right; and I went ahead and purchased the battery charger.  Upon getting the charger home and reading the owner’s manual (you all read the manual don’t you?), I found out that the charger was programmed to automatically know whether to charge for a 12-volt or a 24-volt battery bank.  I’m sure glad that I read the manual and didn’t just start unscrewing the back of the charger.  Upon further reading I discovered that disassembling the charger voids the warranty.

95% of my motor usage is motoring from the marina to go sailing and then back to the marina after my sail is done.  The Torqeedo is perfect for this application.  My two favorite destinations for overnight “weekending” trips are three and eight nautical miles from the marina (~6-nm and ~16 nm round-trip distances).  Again, the Torqeedo’s range and speed is almost identical to the 8 hp Mercury engine that the Torqeedo replaced.  The biggest difference is with the 5% of the time when Kathy and I are on longer trips around Lake Pend Oreille.  Sandpoint, ID is approximately 28 nm from Bayview where Snickerdoodle is berthed.  Hope, ID is approximately 20 nm from Bayview.  Using a Klein multi-meter, I’ve been able to get a pretty good idea regarding how many amps per hour the Torqeedo uses at different speed settings.  This information helps me select the speed that the motor should be set at relative to the distance I’ve got to travel and the charge left in the batteries.  - - Fortunately, there is shore power available at both Sandpoint and Hope - - At 2.5 to 3.0 knots boat-speed, the battery bank will last for about eleven hours… Of course, I’d only motor that many hours if there was no wind.

I have also purchased the 10-foot long wiring harness for the Torqeedo 2.0.  With this wiring harness, I can use (if needed as a backup) the two Group 24 “house” batteries with 80 amp hours at full charge.  The 10-foot wiring harness just reaches from the motor plug to the battery box in the main cabin under the starboard settee.  I have not had to use this long wiring harness yet… but it’s there if needed – also stored in the fuel locker.

So far this year, the longest distance I’ve motored was ~25 nm.  The lake was “flat calm” the whole way.  I set the motor at about 2.9 knots (according to my Garman GPS chart plotter) and we covered the distance in eight hours with battery charge still available.  After the first two hours, the voltage indicator on the motor showed about a 0.3 volt drop hour-by-hour.  And, the voltage reading on the motor indicated 22.8 volts left in the battery bank at the end of the day.  I did find out the next day that the 22.8 is “variable” depending on engine RPMs ……  While motoring into a ten knot breeze to set sails, I needed to increase the RPMs to about where we would have had 4+ knots boat-speed in calm weather.  The voltage dropped quickly – but we still had enough to set sails…… and to get back to the slip at the end of the sail.

One of the things I’ve really enjoyed with the new Torqeedo is the learning curve that I’ve had.  AND, I’m still learning.  Next is researching solar chargers to augment the initial charge when Kathy and I decide to sail to parts of the lake where shore power is not available.  And, researching whether the Torqeedo will charge the battery bank if the boat is sailing faster than the motor “throttle” is set at.  In-other-words, if I set sails at a boat-speed of 1.5 knots and leave the motor “on” and in the water… will the propeller spin at higher revs as the boat-speed increases – changing the motor into a generator???  Will I need to install a voltage regulator in the circuit in this case???

Finally, I am truly glad that I bought the Torqeedo last spring.  It is quiet - - very quiet.  And, the motor is so smooth running that it is virtually vibration free.  There are no gas fumes to contend with.  There’s no gasoline to purchase.  I paid out a little more money than it would have cost to buy a new 10-hp Honda… but not a lot more…  Many of my sailing friends now are calling Snickerdoodle the “stealth” boat……  Some of the racers are saying that it’s an automatic penalty if they see the motor in the water during a race……… ha, ha

The biggest disadvantage is that I have a really nice 8-hp Mercury outboard engine in the garage still for sale… Anybody interested????????