Kohler-Built, Through and Through

A generator consists of two core components: the engine and the generator itself. While most manufacturers outsource the engine, Kohler designs and builds both. This unified approach reflects Kohler’s commitment to quality, performance, and long-term reliability, making their AC generators especially well-suited to marine applications.

Quiet Confidence at 1500 RPM

Running at a steady 1500 rpm, this generator produces a deep, even rumble. The low, consistent tone is far less intrusive than the whine of higher-revving units, offering a quieter, more comfortable experience on board.

Constant Speed, Optimal Efficiency

This generator runs at a fixed speed—not variable—which is ideal for installations focused on battery charging rather than appliances that cycle on and off. Constant speed allows for efficient loading, and diesel engines perform best under load. Running at low load can lead to cylinder glazing, reducing efficiency and lifespan.

To maximize performance and longevity, the recommended use is simple: run it hard for an hour or more, then shut it down.

Reliable Backup, Not Primary Power

Sized correctly, a generator should run for at least an hour. This model serves as a reliable backup, not a main power source. However, occasional use is important—regular run cycles help keep components lubricated and systems in good working condition.

What size of generator for your boat?

Kohler offers generators in a range of sizes, but for the narrowboat market, we typically recommend either a 5kW or 7kW model. The best choice often comes down to available space in your engine room and how physically flexible you are when it comes to maintenance.

The 5kW unit is 10cm shorter, making it easier to access and service in tighter spaces. For that reason, it’s often the more practical and maintenance-friendly option.