I’ve sailed my boat Ocean Strider 6,000 miles, and the auxiliary drive is an electric engine.
The information available on instruments available for Electric Engines is so much better than if sailing a boat using diesel engine and a basic fuel gauge.
Most boats with diesel engines have a basic fuel gauge, which will give you a rough idea of how much fuel you have in the tank, from that you can make a very rough guess of how far your diesel will take you.
Fuel gauges:
Most gauges in my opinion are really not that accurate, especially if you are healing at the time you look at the gauge. You do however learn by experience to guess with a reasonable level of accuracy and hope to fill the tank before you run out.
Battery monitors:
A decent battery monitor will tell you how many amps you have left at your disposal, how many amps you are using currently, and how long you can keep going at your current draw rate.
If you then check your speed. Times it by the hours you have left in the battery bank at your current amp usage. You can easily work out how far you can travel. Not taking into account current and predicted wind speed.
You can adjust the distance available by reducing your Amps usage, yes which means speed, or if possible adding sail into the equation. It’s so easy!
My boat is 33ft and uses approx 30amps per hour to move at 4 knots, with no current or wind added. I only use 35% of my battery so have 140 amps available from my 400-amp VRLA battery bank. So can travel at 4 knots for 4.66 hours, which will allow me to travel 18.66 miles.
Drawing only 35% from my VRLA battery helps keep it in good order.
Yes, I know there is more to it, but with a little experience, you can get your calculations very precise.
If I had 400 amps of lithium and used 80%, I would have 320 amps available and could travel for 10.66 hours. Making 42.66 miles.
I use my sails for traveling on my boat and have a fairly small battery bank. I’m really happy with Ocean Strider’s capability and my increased sailing ability, which is partly due to not having the easy option of using a Diesel engine.
Having a lithium battery bank should give any sailor the ability to move any distance, with the correct planning, including weather and currents.
