PBIBS 2026: CayCube self contained electrical system

Each of the last few years, the Palm Beach International Boat Show has gained momentum and prominence. This year that momentum continues with several new product announcements. The CayCube from Cay Electronics is making its Florida debut after an appearance at the Newport show and caught my eye. This self contained AC and DC power system offers numerous integration options and helps solve numerous problems for boaters, boat yards, and service providers.

As CayCube co-creator Rufus Van Gruisen explains in the video above, CayCube is a self contained 48-volt DC and 120/240-volt AC power system. CayCubes are available in three models. The smallest offers 5 kilovolt-amps (KVA) of inverted AC power and 20 kilowatt hours (kWh) of energy storage. The middle sized unit offers 10 KVA of inverted AC power and 40 kWh of energy storage. The largest configuration offers 15 KVA of inverted AC and 60 kWh of storage. The units are priced at $28,995, $49,995, and $69,995 respectively. CayCube also offers a single or dual 8kw alternator package with Arco Zeus alternators and regulators for $3,495 and $6,895 respectively.

Let’s get something out of the way right up front. Yes, with some skill, you too can build a product very similar to the CayCube. You can probably build it for less than the retail price of the cubes. But, I don’t think that’s the point of the product. A packaged solution offers significant value and the time to assemble a product like this is far from trivial. Plus, I suspect there’s a strong correlation between regular Panbo readers and those with the skill to assemble something like this.

Cay Electronics estimates a retrofit of lithium batteries, inverter, and attendant systems and components requires 40-80 hours of labor. As labor rates close in on and exceed $200 per hour, that represents somewhere between $8,000 and $16,000 of installation labor. Having completed quite a few projects of that scale, those numbers feel right, or maybe even low.

What’s inside?

Fundamentally, a CayCube is a boat’s AC and DC power system in a box. That box contains carefully selected and integrated components. Nearly all those components are familiar, commodity parts. The power conversion and conditioning equipment is Victron’s, the batteries are from Solid State Marine, and the bus bars and distribution components are mostly Blue Sea and BEP.

A Victron MultiPlus II sits at the heart of the cube. The inverter/charger carries a rating of either 5,000, 10,000, or 15,000 VA depending on the CayCube model. In a familiar approach, they have selected a 230v model programmed to output 240v, 60hz AC power. That power feeds an Autotransformer providing 120/240v split phase output for all 120 and 240 volt loads on the boat.

The DC side of the CayCube brings power from the batteries directly to Class T fuse holders. A large contactor sits on the output of the fuses and controls DC power to the system. From the contactor, DC power routes to the inverter’s DC connections and to the DC connection on the CayCube’s DC output box. The power connection on the output box can feed the boat’s DC house system at 48 volts. For boats with lower voltage house power systems, DC-to-DC converters — and possibly lower voltage batteries — will need to be employed.

Control and management of the CayCube comes from a Victron Cerbo and touch screen. Cay has not tried to disguise or obfuscate the obvious Victron bones of the system and I think that was a good decision.

I haven’t done a thorough evaluation of the cost of the components and I don’t think it’s really the point. But, just looking at the cost of the batteries ($15,000), the inverter ($1,500), and the Autotransformer ($500), I don’t see as large a premimum as I might have expected. The numbers of the CayCube do get up there, especially at $70,000 for the 15KVA/60kWh model. But, that’s a huge amount of power and not a power system we typically see quoted as a single number.

Where does CayCube fit?

Writing that heading, I was thinking about what applications make sense with CayCube. But, I realize to have that conversation, we need to talk about the physical size of the CayCube. Taking a look at the technical specs, the CayCube comes in very close to typical generator sizes. For example, a Cummins Onan generator sized from 4-5 kw weighs 365 pounds and occupies a space 20x26x21. Stepping up to a 9.5-13kw generator, the generator weighs in at 695 pounds and occupies 22x41x23.

Overall, it appears a similarly sized CayCube may be slightly larger than a similarly sized generator. However, without an exhaust system, cooling water system, and fuel lines, the total system size and weight is likely to be the same or less for a CayCube. Additionally, most boats for which a CayCube is an appropriate tool would have an inverter, deep-cycle batteries, and other components elsewhere anyways.

So, without getting too hung up on the physical space, what applications make sense for a CayCube? As Rufus mentions in the video, there are quite a few potential applications. At the Palm Beach Show, Hinckley Yachts brought a 37-foot picnic boat demonstrating their refit program. The boat included a CayCube 5kva/20kWh. Hinckley will offer CayCubes to refit customers. A larger, primarily day use boat strikes me as an ideal platform for the CayCube in a generator-less application. These boats tend to be stored at a dock with shore power and typically don’t stray too far from a dock or for too many nights.

Longer range boats with generators can benefit dramatically from a CayCube and the ability to run the generator less. Plus, when the generator is running, its output can be better utilized to quickly charge the CayCube’s batteries. Even larger boats with multiple generators can look at replacing one generator with a CayCube and making use of alternator charging to provide redundancy while also reducing generator run time.

Final thoughts

I am a big fan of any solution that reduces generator run time. No matter how quiet, I find the rumble and exhaust of a generator highly disruptive to the peace of an anchorage. But, I also love my creature comforts. So, a system that allows me to minimize that disruption while still providing all the comforts ranks very highly.

I don’t foresee a hands on test of a CayCube. I don’t think I could fit one anywhere but in the cabin of my little Edgewater 28. But, I do look forward to keeping up with Cay Electronics and seeing where they take the product. My hunch is that they will find plenty of demand for a pre-engineered, pre-integrated, marine specific power system with best-of-breed components.