Inverters for boats have come a long way in recent years as inverter technology has advanced. These advances have occurred with hardware developments and related software. Along with that has been physical size reduction and a big increase in reliability. Boat inverters range from small portable units of around 150W up to large fixed systems of 5kw with some units that can be paralleled with automatic synchronization. The combination charger/inverter is a very common installation on many boats merging the two functions.
That is the question everyone should ask before embarking on what can be an expensive undertaking. If you have the cash and decided you are doing because you can then what follows is not for you. Recently I sat around the saloon table with a bunch of cruising buddies sipping coffee and we had a big discussion on whether inverters were worth the money and installation issues such as battery capacity, charging and so on. The first big question is why do you want an inverter. Bart Dinkledonk or Dinkle as we call him(because his Afrikaans name is unpronounceable) from South Africa reckons that like Africa, inverters are for sissies and his Aussie mate Clyde reckons much the same. But then these two Luddites also think spirit stoves and oil lamps are enough. The rather robust conversation ended with “You’re the bloody marine electrical bloke, go write about this and try and demystify the whole subject for us all!”
Our robust discussion went well, some said they wanted to power their hand tools, but given that most people have a suite of battery powered drills and other devices such as grinders and so on all off the same skin then that was hardly an excuse. It has to be said that they need to be recharged though. On the top of the AC list these days are device chargers, for the smart phone, the tablet and the laptop. You don’t need a very big inverter to do that, and more about that later. So do you really want to power up something larger, perhaps a television and the DVD player. Larger loads include microwaves, blenders, coffee machines and hair dryers to name but a few. I know someone who wants to power their yoghurt maker and another his blender for Margarita’s. (I have a 12 volt blender just for this reason). It has to be said that inverters for boats powering loads of 5 amps and more consume a lot of battery power.
Scenarios differed with respect to inverters for boats, some people have the boat moored in a marina hooked up to dock power most of the time. They occasionally take a weekend or a couple of weeks vacation and go off somewhere. Then there are those who swing off a mooring or anchorage somewhere and rarely go into a marina except for refueling. And then there are those who wander the seas and again go in to refuel and go out again. Among these various boating scenarios are those who have no AC power at all on board, mostly those who do not frequent a marina so don’t even use shore power, and there are plenty of people about who fall into this category. Then there are some of those who have an AC generator installed to take care of their AC power requirements, but that’s a different subject all together. Lastly those who sit at a marina most of the time and have a combination of shore power, generators and inverters. So then comes that seemingly endless question of inverters vs generators.
Questions, questions! How long can you run the inverter for? What is the waveform issue with inverters for boats? what about combination inverter chargers? Do inverters really pull that many amps? How much inverter power do you need? How much battery capacity do you require? How are you going to recharge the batteries? Where do you plan to install the inverter? Then its installation, and mounting the boat power inverters. Finally there is the connection of wiring, including the battery cables. Boat inverters have many issues to consider.
The latest generation inverters for boats use what is termed pulse width controlled Insulated Gate Bipolar Transistors (IGBT) to perform DC to AC inversion which provides precise output control and waveforms over older Metal-Oxide Semiconductor Field Effect Transistor (MOSFET) type systems. Associated transformers have also been reduced in size and weight as conversion is done at high frequencies. Reliability on most systems is greatly increased over earlier generation units as electronics has evolved. There are boat inverter installation requirements. Many ask for a suitable boat inverter wiring diagram, and most manufacturers have them within their installation manuals. There are many boat inverter manufacturers. Some of my favorite boat inverter manufacturers are Xantrex and ProMariner from the United States who make some very well engineered inverters, and have owned one of their units myself. From The Netherlands and with a global presence are Victron Energy and Mastervolt. I have installed several of their inverters for boats.