Electric outboard systems
The simplest option is another battery. With only one plug and one clip it is an easy procedure to change. The easiest way to remove the battery when you are in the boat is to turn the outboard around 180 degrees so the tiller is facing away from you and the battery is towards you in the boat. This makes lifting the battery more accessible to lift off. Although this is the simplest way to get more range, it not the only way.
The solar charger can be used while you are motoring or stopped, turning your electric boat into a solar powered boat fuelled by the sun.
There are some limitations on this which need to be considered. The maximum solar panel size the charger can take is 180 watts and panel voltage must be less than 35V. The motor can draw a maximum of 1000 watts and the battery stores 1kWh (1000Wh).
What does this mean to your motoring if you have full sunshine and 180 watts of solar after losses (cable and charger) at the motor? You will have 150 watts available which is less than your full power of 1000W. This does not sound good but does this mean it doesn't work? No, because in practice you do not motor all day and when you stop the solar is continually storing power in your battery.
How much power will you get from solar during a day? This depends on how big the solar panel you have is, whether it is winter or summer, how sunny the day is, the angle of the panel relative to the sun and any shade of the panel during the day. As a rough guide, for a panel exposed to full light in Australian conditions, take the wattage of the solar panel and multiply by 4 . Example: 180 watt panel X 4 would generate 720Wh per day.
As I said before much depends on how much sunlight there is to harvest. The charger can accept 180 solar watts, and you can wire it differently to use more solar, see below...
WHICH SYSTEM IS BEST FOR YOU
Just as no two boats are the same nor will be the electrical systems. Similar boats with different owners, uses and expectations can require very different systems. Even the choice of primary power source will vary depending on where you are in the world. Solar, wind, mains power and generators all have their place in the varied world of sailing. All of these differences is what makes boating interesting.
Betts Boat Electrics can be contracted for boats in Australia to do a technical assessment of the pros and cons of each method for your boat. There is no right or wrong way. The best way is the way with which way the you, the owner, feel most comfortable and meets your needs.
Written by Mal Betts
Betts Boat Electrics