About generators for electric sailboats
If you sometimes need to go far on an electric motor, then it will be difficult to do without an internal combustion engine generator. There are several options for solving this problem, I will describe them in this article.
The simplest way : use an inverter generator with a power of up to 2-3 kW . There are many such generators on sale, they give out 220V AC at the output, which allows you to connect a conventional charger for your batteries to them and charge them from the shore. The only fundamental difference: the power of the charger must be less than the maximum power of the generator by about 20% for the long life of the latter. This method is very easy to implement, the generator can be delivered from the locker (its weight will be only about 20 kg for a 2 kW generator).ra) and start on deck by connecting the cable to the charger. You will have to endure the sound of the generator (although there is a noise-absorbing casing, it still works annoyingly loud). In addition, work in the rain will be difficult due to high voltage (220V) and the risks associated with it. As I wrote above, this is the easiest to implement, this is the main advantage of this method. The price is quite high, because high power inverter generators are not cheap.
A bit more complicated and more correct : installation of a 220V generator inside the housing with exhaust gas removal and ventilation of the generator compartment . You can also buy such a generator without any problems - the choice is huge, for different capacities, up to 10-15 kW. Here you have to sit down hard at the tools, because. ventilation and removal of hot gases through the case is not so simple. It is fashionable to solve the problem with hot exhaust by adding water to the exhaust system, it must naturally be made of stainless steel and a pump is required, whichwill pump sea water into the exhaust system. This will reduce noise, odors and exhaust temperature at times. Ventilation should be done with non-sparking electric exhaust fans. Such generators are inexpensive, but the exhaust system and ventilation will also cost a pretty penny.
Well, a completely experimental method : installing a homemade constant voltage generator , tuned to the voltage of your battery, is stationary in the case, just like in the previous version. What are its benefits? There is no need for a charger . This leads to an increase in overall reliability - if the charger breaks, you can still charge your batteries and go under the electric motor. In addition, without additional energy conversions (instead of "gasoline -> 220V AC -> 48V DC" there will immediately be "gasoline-> 48V DC") the overall efficiency of converting gasoline (or diesel) energy into electrical energy will be higher, resulting in fuel savings per hour of operation of the electric motor compared to using 220V generators and a charger. Of course, I chose this option for implementation on your boat :) For the money, this option is about the same as the previous one.
This article will be updated when the generator installation is complete.
Why is a buffer battery needed on a hybrid sailboat?
Because without a buffer battery, the generator loses the ability to operate at optimal speed, it will either adjust to the load of the electric motor (already different speeds) or operate at maximum power - and this is wasted fuel and noisy. With a buffer battery, the generator does not always work, but when the battery is low and until it is fully (or almost completely) charged.