{"id":813,"date":"2022-08-15T09:17:29","date_gmt":"2022-08-15T13:17:29","guid":{"rendered":"https:\/\/www.sailons.com\/northerncomfort\/?page_id=813"},"modified":"2022-08-18T08:17:34","modified_gmt":"2022-08-18T12:17:34","slug":"tech-review-is-it-worth-it-to-liquid-cool-your-electric-motor","status":"publish","type":"page","link":"https:\/\/www.sailons.com\/northerncomfort\/tech-review-is-it-worth-it-to-liquid-cool-your-electric-motor\/","title":{"rendered":"Tech Review: Is it worth it to liquid cool your electric motor?"},"content":{"rendered":"\n

Well to start off, I wanted to throw out some caveats. This article is from my experience with my sailboat, a 1975 Hughes\/North Star 35\/1500 and converting her from gas to electric power.<\/p>\n\n\n\n

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There were quite a few people that asked my range and how I was dealing with cooling. One important piece of data is that when I originally bought the boat the shaft alignment was not great. I found that the shaft when centered was very difficult to turn. After investigation I found that my cutlass bearing support strut was slightly bent. I took some time to straighten that<\/a> and I went from struggling to turn the shaft to wondering how I can add a break to it to stop it from free turning under sail. I can’t in words explain how much easier it was to turn after I realigned it. As you can imagine, the effort to turn the prop shaft dropped significantly which also in turn drops the heat considerably. I believe I went from 1500 watts to 750 watts to get my 3 knots. It was that significant.<\/p>\n\n\n

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The second thing for me is that I never motor anywhere. I motor out of my slip and raise the sails. I have learned to trust my gear and I sail almost into the last 250 feet left to motor. As I originally didn’t have any liquid cooling, I was reliant on air and as I motored I typically left the the cockpit door open and as such ambient air was my cooling. I have had a couple of shut downs, once blown off anchor during 58 knots winds and once going through the Hamilton canal\/Burlington Lift Bridge<\/a>, that was interesting…<\/p>\n\n\n\n

I also test crossed the Hamilton Harbour at 3 knots quite a few times. Lets just round that at 3 miles\/5 km across. I never had any real issues aside from I knew the controller got hotter the faster you go, so I just kept it at my 750 watts, and crossed at 3 knots (3.4 mph\/5.56kph). I usually made it across within an hour.<\/p>\n\n\n\n

A big part of my decision to go slow is that my batteries could only handle a 25amp draw rate. If I took power out of the batteries any faster than that I would have damaged my batteries. This year, I changed to Lithium LiFoPO4 batteries and I am now finding myself with cooling alarms, and hence my testing as I have run the motor now at 75 amps for quite some time (to the point of overheating the controller).<\/p>\n\n\n\n

Controller vs Motor Temperatures<\/h2>\n\n\n\n

Gear:<\/p>\n\n\n\n