The Electric Engine
During the past several months I have fielded numerous questions about Wookie’s engine so decided to post a little more detail.
My big gamble with Wookie was opting to go “green”. My choice for this is the Torqeedo Cruise 2.0 R/T (remote throttle) outboard which is rated as a 5HP motor but equivalent to most 6HP outboard gasoline motors. I am depending on that famous German engineering for this engine to perform as advertised. To date I have been quite satisfied with both performance and quality.
Getting to understand battery requirements (in my case two 105amp AGM batteries combined to give me 24V of 105 amps of power), battery charger requirements, separating house batteries from engine batteries, installing connectors and the remote throttle have all been a bit of a challenge. Interesting and a real challenge.
It amazed me how few professionals were out there to assist with the questions I had. Also my small boat did not receive any interest from Torqueedo here in the USA even though I did try. Consequently I have felt like a bit of a pioneer. However the reality is that looking back most of this was “not” that difficult. My concerns were based on the unknown, the relatively large expense for something I was not sure would work and the never ending mystery of electronic components.
At this stage, I have no regrets.
Engine Brackets (Stern and Rail)
The first step on this journey was to build a new mount on Wookie’s stern. I did not like the usual spring-loaded ugly “huge” bracket that was available for outboards so decided to have one made. My goal is to lower the engine from a stern rail mount down to a running bracket when in use. Once done for the day I raise the engine back on to the stern rail and rinse it well with fresh water. Once thoroughly dry I cover it with a bespoke bag to protect it from the elements. I took the engine to the sailmaker and they made it for me with the intent to keep the rain and sun off the engine.
Below are images of the NEW engine mount compared to the OLD one used for the gasoline outboard. Also a few images of the engine cover.
The remote throttle that comes with the engine is an intelligent unit that monitors various aspects of your batteries while operating the engine. By following clear Torqueedo instructions I calibrated the throttle to my AGM batteries. By doing this I set the throttle to show PERCENT availability of battery, NAUTICAL MILES PER HOUR, speed in KW/Hour and time remaining in HOURS-MINUTES. I also added a VICTRON battery monitor to the 24v system which I use to compare to the throttle displays. These are normally within a couple of percentage points of each other but it gives me a very clear understanding of how much battery capacity I am using and how much is left.
I also made a stainless steel bracket that mounts easily on the bottom of the throttle in holes that are pre-tapped for small bolts just for such an event (the quality of German engineering). This I can either attach straight on my tiller or onto a wooden bracket in the stern of my cockpit. This bracket is on the wooden cover that hides the engine fitting. I tried the throttle on the tiller but found it got in the way. I definitely do like the mount I use.
Pictures Of Cockpit Engine to Battery Connector
These are installed as far forward as possible under my companion way ladder. ONE HOUSE AGM battery 90amp and TWO ENGINE AGM BATTERIES 105amp. The images below show a RED switch which is for the 12v battery. The BLACK switch is for the 24v system. As stated the two 105amp AGMs are combined together to make a SINGLE 24v battery of 105amps. Torqueedo has a fabulous 24v battery with intelligent features but is very expensive. I really like my system because this is 25% of the price and if required I can always feed 12v off ONE of the 105amp AGM batteries. A great backup for my house needs.
The following information is based on my personal usage of the electric motor (I am NO expert).
Maximum Engine Speed 2100 KW/H but this will give me only an hour of run time. However this is a lot of power – a solid 6hp and will push Wookie in tough conditions.
Normal running is 700-800 KW/H for about 4 hours or 9-12nm depending on conditions. This is my normal usage of the engine. I avoid using more than 50% of the battery capacity or 2 hours running for about 4-6nm.
Currently I use a 10amp charger to gently charge my 24v system and a 6amp for the house battery. Three hours of charging normally gets my batteries to 100% charge. I am in the process of building a “hard dodger” with 2 by 30KW solar panels imbedded into the top as trickle chargers. One is a 12v panel and the other is a 24v panel. Both of these will go through their own controller. I will be posting a dedicated section of this in the next few months.
The battery connector fits through a normal 30 amp dock fitting which I use to protect the battery connector attached on the boat (I do not really like the one supplied by Torqueedo but by using the dock fitting I can keep my connector dry when not in use). Obviously one could mount the engine permanently onto the boat and run the cables directly from the engine to the batteries. I didn’t go for that as I prefer to remove the engine when not in use and keep it clean out of the water. Its an expensive unit. There is also a “pod-drive” unit which can be permanently mounted (see Torqueedo’s catalog).
The engine is kept clean and requires no maintenance. It is quiet underway and is light-weight on the stern of the boat. Torqueedo provides a detailed catalog online with all the engine specs.
It is also light enough to move about around the boat. When I leave the boat for extended periods I store the engine between boat cushions on my cabin sole.
I hope this information will answer some of the questions I normally get asked.
Thanks for reading my blog.