Larry Luce, Courtesy Revatek The Altion Max is the latest in small, discrete, but highly functional alternator control technology with the ability to simultaneously manage two alternators of differing voltages.
Beginning in the late 1970s, the progressive adoption of solid-state electronics into numerous components of marine electrical systems resulted in a qualitative shift in overall capabilities. These were years that saw the introduction of first-generation multi-step voltage regulators coupled to high-output alternators, switch-mode battery chargers, and modified-sine-wave DC-to-AC inverters.
The Pioneers
High-output alternators with multi-step voltage regulators were first popularized by three Seattle-based companies competing to dominate the marine marketplace—Bill Montgomery’s Balmar, Rick Proctor’s Cruising Equipment Company, and Dave Smead’s Ample Power.
The electrical side of the first edition of my Boatowners Mechanical and Electrical Manual, published in 1990, described the necessary structure for these emerging systems and explored the various components in detail, starting with batteries. The knowledge for this was partly based on my own experience and experimentation but was primarily gained by picking the brains of Montgomery, Proctor, and especially Smead, who was consistently on the cutting edge of development—an under-appreciated genius to whom we all owe a debt of gratitude.
The years went by. Proctor sold Cruising Equipment Company to Xantrex who proceeded to crash their market share. Ample Power went bankrupt, and Smead died of a heart attack in the middle of a motocross race. By default, Balmar became the only game in town. Predictably, the pace of innovation slowed.
The Interregnum
Despite steady increases in power and complexity of onboard electrical systems over the last few decades, the core energy generation and distribution structures did not fundamentally change. As a practical measure of that substantial but predictable technological evolution, the three subsequent printings of my manual all retained the structure of the original edition, but with a ton of additional material making the fourth edition approximately three times as long as the first.
In the interim, lithium-ion battery chemistries were advanced and refined, eliminating some of the persistent impediments to powerful DC-based systems such as moderate charge acceptance rates and other negative features of all lead-acid batteries. Simultaneously, alternators steadily improved their output and generating efficiency. Various research and development programs, such as the EU-funded HyMar project, and the subsequent Parker-funded On Engine Generator (OEG) project, both of which I was involved with, explored the potential and the benefits of fully exploiting the ‘headroom’ between an engine’s full power curve and a propeller’s power absorption curve when a boat is under way. (See “The Hybrid Conundrum” in Professional Boatbuilder No. 142, page 26.)
These efforts informed an emerging awareness that the control side of increasingly powerful alternators must move beyond simple voltage commands based on battery state-of-charge readings to encompass more complex engine data input. We saw how the loads created by an alternator needed to be managed to optimize performance and efficiency in the region between an engine’s full power curve and a propeller’s power absorption curve. Note that this is unique to the marine world because our engines, unlike in the automotive world, only have forward and reverse gears, with no intermediate gears.
The Dam Breaks
In 2014 Bill Montgomery sold Balmar to CDI Electronics, and Balmar operations moved from the Seattle area to Huntsville, Alabama. Key personnel left Balmar and launched a new alternator controller initiative under the Wakespeed brand name. Between Wakespeed and the OEG project (subsequently rebranded as the Integrel system) the boating industry benefitted from a new burst of alternator controller innovation focused on integrating key engine parameters into the control algorithms. Wakespeed popularized the concept of “white space utilization,” which encompasses the optimization of operating in that region between an engine’s full power curve and the propeller’s power absorption curve.
Balmar was slow to react to the challenge to its historic dominance of the marine alternator controller marketplace. Belated moves were initiated several years ago, but then Dometic bought CDI Electronics and with it Balmar. While Balmar has yet to catch up, other marine technology companies have seen an opportunity and stepped into the marketplace. This past year we saw the Zeus controller launched by ARCO, with very similar functionality to the Wakespeed and Integrel controllers. And at this year’s IBEX there was another entry, the Altion Pro and Altion Max controllers from Revatek, which seem poised to raise the bar even higher for alternator controller performance.
Altion Max — The Latest Contender
The Altion Max includes the white space utilization capabilities of other controllers and has the Bluetooth and WiFi connectivity also being integrated into competing products. What sets it apart is an ability to control two separate alternators operating at different voltages by applying a customized management algorithm for each alternator. The maximum allowable field current for each alternator is stated as 16A, more than adequate for the most powerful models in the marine market today. The Altion Max, for example, can simultaneously manage and optimize the outputs of a 12V and 24V alternator, or a 12V and 48V alternator, or a 24V and 48V alternator. Revatek is integrating its controller with various CAN-based communications systems. The Altion Max packages its advanced capabilities into a device with a smaller footprint and a more compact volume than any competition.
Courtesy Revatek The Altion Max controller has the capacity to communicate on NEMA 2000 networks, and through USB-C and Ethernet connections.
I’ve spent decades focused on improving the performance of DC-based onboard systems. The Altion Max, which I first encountered at IBEX 2024, is one of the more exciting new products in this field that I’ve come across in recent years. While it has yet to prove itself to me in real-life service, its mere existence is proof that we are living through a level of innovation in the control side of alternators and DC-based systems unlike anything we have seen since the 1980s.
When coupled to lithium-ion batteries, we currently have all the ingredients we need for another dramatic improvement in the power and efficiency of DC-based marine energy systems. It is an exciting time to be working on new technology in this field.
