EV Charging Power Cabinet Buyer's Guide: Split-Type vs. All-in-One

# EV Charging Power Cabinet Buyer's Guide: Split-Type vs. All-in-One

The power cabinet is the part of a DC fast charging system that converts AC grid power to DC battery power. Drivers never see it, but it sets your power ceiling, your port count, and most of your 10-year maintenance bill. Yet it determines how much power you can deliver, how many vehicles you can serve, and how much you will spend on electricity and maintenance over a decade.

This guide explains the split-type architecture (separate power cabinet and dispenser) versus the all-in-one architecture (integrated cabinet with cable management). We wrote it for buyers who need to choose between the two for a depot, a fleet yard, or a public charging hub. We manufacture split-type systems, so we have a bias, but we will be honest about where all-in-one wins.

What a power cabinet is

A DC fast charger has two main parts. The power cabinet contains the rectifiers, inverters, transformers, and control electronics that convert AC to DC. The dispenser contains the cables, connectors, and user interface that drivers interact with. In an all-in-one charger, both parts are in a single enclosure. In a split-type system, they are separate units connected by DC busbars or cables.

The split-type architecture is sometimes called a distributed or centralized power architecture, depending on whether one cabinet feeds multiple dispensers. The all-in-one architecture is sometimes called monolithic or integrated. The terminology varies by vendor, but the physical difference is consistent.

The power cabinet is where the heat, noise, and electromagnetic interference are concentrated. It is also where the efficiency losses happen. A 95 percent efficient cabinet at 480 kW loses 24 kW as heat. That heat must be managed with cooling fans, heat exchangers, or liquid cooling. The dispenser, by contrast, is mostly passive. It contains contactors, cables, and a display, but the heavy power conversion happens in the cabinet.

For a deeper comparison of modular and monolithic designs, see our article on modular vs monolithic DC fast chargers.

Split-type vs all-in-one architecture

The split-type architecture puts the power electronics in a cabinet that can be located away from the dispensers. The dispensers are smaller, lighter, and contain only the cables and connectors. One power cabinet can feed multiple dispensers, and power can be allocated dynamically between them.

The all-in-one architecture puts everything in one box. The cabinet is larger, heavier, and contains both power electronics and cable management. Each all-in-one charger serves one or two vehicles, and power is fixed per unit.

The split-type approach has three advantages. First, the power cabinet can be located where space is available, while dispensers are placed where vehicles park. Second, power can be shared between dispensers, which improves utilization. Third, maintenance on the power cabinet does not require blocking a charging lane.

The all-in-one approach has two advantages. First, installation is simpler because there is only one unit to place and wire. Second, the per-unit cost is lower for single-gun, low-power applications where power sharing is not needed.

There is a third consideration that is less obvious: noise. The power cabinet contains cooling fans and transformers that generate audible noise. In a split-type system, the cabinet can be located away from the driver interaction area, behind a fence or in a utility room. In an all-in-one system, the noise is at the charging lane where drivers stand. For urban depots with noise ordinances or for sites near offices, this can be a deciding factor.

Power and cooling comparison

Power range is where the architectures diverge most. All-in-one chargers typically max out at 180 kW to 240 kW per unit, with dual-gun configurations sharing that power. Split-type systems can scale from 30 kW to 480 kW or more by adding power modules to the cabinet.

FBK POWER's split-type system uses modular 30 kW and 40 kW power modules. A cabinet can hold up to 12 modules, giving a range of 30 kW to 480 kW. The DC480TFS01 power cabinet pairs with the DC550KSK01 dispenser, and one cabinet can feed multiple dispensers depending on configuration (our standard configurations support one or two dispensers per cabinet).

The modular approach means you can start with 120 kW and add modules as your fleet grows. Each module is hot-swappable, so you can add capacity without powering down the entire cabinet. This is different from an all-in-one charger where adding capacity means buying a new unit.

Cooling is another difference. All-in-one chargers use forced air cooling for both power electronics and cables. Split-type systems can use forced air in the cabinet and separate cooling for the cables. For high-current applications above 250 A, liquid-cooled cables become necessary, and the split-type architecture makes it easier to integrate liquid cooling without redesigning the entire unit.

The cooling strategy also affects where you can place the equipment. An all-in-one charger with forced air cooling needs clearance for intake and exhaust. A split-type cabinet can be placed in a utility room with ducted cooling, while the dispensers are placed in the parking area with passive cooling for the cables.

For more on cooling options, see our article on EV charger cooling systems.

Installation and site requirements

Installation cost and complexity differ significantly between the two architectures.

All-in-one chargers require a concrete pad, a trench for power and data cables, and enough clearance for the cabinet doors to open. The unit is heavy, weight varies by manufacturer and power rating, which requires a crane or forklift for placement. Electrical connection is straightforward because there is only one AC input and one or two DC outputs.

Split-type systems require two pads: one for the power cabinet and one for each dispenser. The cabinet pad needs to support more weight, typically larger cabinets for high-power systems. The dispenser pads are smaller because the dispensers are lighter, typically lighter dispenser units. The DC connection between cabinet and dispenser requires busbars or heavy cables, which adds electrical work. However, the dispensers can be placed at a distance from the cabinet, limited by cable voltage drop and local code, which gives layout flexibility.

Site planning matters more for split-type systems. You need to plan the cabinet location, the dispenser locations, and the cable routes between them. For a depot with irregular parking geometry, this flexibility can reduce civil work. For a simple rectangular lot, the all-in-one approach may be faster to install.

One installation factor that is often missed is future expansion. If you install an all-in-one charger today and need to add a second charger next year, you need a new pad, a new trench, and a new electrical run. If you install a split-type cabinet today with two dispensers, adding two more dispensers next year requires only the dispenser pads and short cable runs. The cabinet and electrical service are already sized for the full capacity.

The electrical service requirement also differs. An all-in-one charger needs a dedicated breaker and conduit run for each unit. A split-type cabinet needs one large breaker and conduit run, with smaller runs to each dispenser. For a four-dispenser site, the split-type approach can reduce electrical infrastructure cost because the utility connection serves one cabinet rather than multiple standalone units because you are not duplicating the service entrance.

Cost comparison over 10 years

The 10-year cost difference between split-type and all-in-one depends on utilization, expansion plans, and maintenance strategy.

Hardware cost for all-in-one is lower per port for single-gun, low-power applications. A 50 kW all-in-one charger costs less than a 50 kW split-type cabinet plus dispenser. However, for multi-port deployments, the split-type architecture becomes more cost-effective because one cabinet can serve multiple dispensers.

Installation cost for all-in-one is lower for simple sites. The single-unit design reduces trenching and electrical work. For complex sites with multiple charging lanes, the split-type approach can reduce total civil work because dispensers can be placed closer to vehicles.

Maintenance cost favors split-type for high-utilization sites. When a power module fails in a split-type cabinet, the remaining modules keep the other dispensers running. When an all-in-one charger fails, the entire unit is down. For a depot where downtime costs $500 per hour, the split-type architecture can pay for itself in avoided downtime.

Expansion cost favors split-type. Adding a dispenser to an existing cabinet is cheaper than adding a new all-in-one charger. For fleets that expect to grow from 10 vehicles to 50 vehicles over five years, the split-type architecture defers capital cost.

For a full TCO model, see our guide on EV charger total cost of ownership.

Which architecture for which use case

Choose split-type when you need high power, multiple dispensers, or future expansion. The architecture is well-suited for fleet depots, bus yards, and public charging hubs where power sharing and layout flexibility matter. It is also the better choice when you expect to add capacity over time, because you can add modules and dispensers without replacing the cabinet.

Choose all-in-one when you need a simple, single-gun installation at lower power. The architecture is well-suited for workplace charging, retail parking, and small fleet depots where one or two vehicles charge at a time. It is also the better choice when installation speed and simplicity are more important than long-term flexibility.

For more on how to choose between centralized and distributed power, see our article on centralized vs distributed power architecture.

Buyer checklist

Before you specify a power cabinet, answer these questions:

• How many vehicles will charge simultaneously, now and in five years?
• What is the maximum power per vehicle, and does it justify liquid-cooled cables?
• How much space is available for the power cabinet, and how far can it be from the dispensers?
• What is the cost of downtime per hour, and does redundancy justify the split-type premium?
• What is the expansion plan, and does the architecture support adding capacity without replacing hardware?

If you are evaluating suppliers, our guide on how to select a DC fast charger manufacturer covers the audit questions that apply to any vendor.

Bottom line

The split-type and all-in-one architectures solve different problems. Our honest read: below about 100 kW and one or two guns, buy the all-in-one and keep it simple. Above that, or anywhere you expect to grow, the split-type pays for the extra engineering in the first expansion you do not have to rip out.

FBK POWER manufactures split-type systems because we believe fleet depots and public hubs need the flexibility. But we recognize that all-in-one is the right choice for many sites. The key is to match the architecture to your utilization pattern, expansion plan, and downtime tolerance.

For a spec sheet on our DC480TFS01 power cabinet and DC550KSK01 dispenser, request a quote and we will send the factory test reports and UL certificate details.