Miguel is a retired man who decided he wanted to enjoy his well earned free time. Playing petanque at the park? Checking construction works in progress around the quarter? Playing dominoes at the bar? No, he bought a boat. Specifically a Dufour 310: a nice sailing boat slightly over 9 meters, with fine lines, modern interiors and easy to steer, even single-handed.

And there he is, making the most of her; enjoying in the sunny days, fighting the elements when the wind blows and the sea gets choppy. Can you think of a better way to spend the day? But we can always find fault with any pleasure. In this case it was the simple delight of being able to plug a coffee machine for a good coffee.

No need for drama, that can be easily fixed! Electronics, as usual, comes in handy. As many boats, the Dufour 310 has batteries for the electricity supply on board: 12 volts direct current. You just have to install an inverter.

Inverters are electronic devices that transform direct current (DC) into alternative current (AC), of a desired voltage and frequency. For instance, any installation of photovoltaic solar panels needs an inverter so that the generated current (direct) can be transformed into alternative, and hence it can be distributed to the general electrical network. (The opposite device is a rectifier, which transforms AC into DC. Moreover, there are combined devices inverter/battery charger.)

There a lot of brands and models. For the Dufour, at Medenisa we chose a Mastervolt 12-220 with and output power of 2000 W. With it we can get the 220 V* AC as we have at home. This model allows a continuous consumption of 1800 W (more than enough to use a microwave, for instance; or a portable heater, or a washing-machine), taking up the same space than that of a couple of shoe boxes.

Mastervolt 12/2000 inverter; image from Mastervolt catalogue

The installation is quite straightforward. When we buy a boat, she usually comes from the shipyard with power points (sockets) installed, but connected to and empty distribution board. We connect the inverter to that board, so that now we have electricity supply (AC) to the sockets. There you can then plug your favourite device (for Miguel, his coffee machine). Once the inverter connected to the board, you have to connect it as well to the batteries, adding a protection fuse to the line.

Installation instructions from Mastervolt’s Owner’s Manual

The inverter can run only through the batteries for 10 to 15 minutes (enough for a couple of cups of coffee). But if you want to have any device connected for longer time, you have to start the engine, so that its alternator will charge the batteries – as the batteries will be discharging while the inverter runs.

Together with the inverter, Medenisa’s technicians supplied and installed as well two Raymarine equipment: a VHF Ray260E radio (with digital selective call- DSC), with a secondary station (repeater) at the cockpit (and with its antenna, obviously); plus a 18” Radome Digital antenna (power: 4kW), with a 48 miles range. This radar has a double-target function, i.e. you can check two targets on the screen at the same time and independently). The interface of the radar was fully integrated with t the existing GPS/plotter equipment, so that the same screen can be used for the three applications.

The project was swift and easy; we brought it to a satisfactory conclusion, and we hope we’ll be able to celebrate it having a nice cup of coffee with Miguel on board, next weekend.

* Actually the network supply is 230 V, but in the past it was 220 V, and this name has prevailed.