Every facet of mobility is undergoing a transformation toward more electric and autonomous transportation. For the freight industry to make this leap, megawatt charging needs to be readily available.
However, delivering at the required scale adds complexity that established validation approaches can’t handle. That puts test and validation on the critical path.
Megawatt charging is different
McKinsey projects the autonomous heavy-duty trucking market will reach $600 billion by 2035, with early commercialization focusing on driverless highway operations and transfer hubs, where trailers are handed off between machine and manually driven freight vehicles.
The Megawatt Charging System (MCS) is designed to deliver the high power needed for heavy-duty electric trucks and demanding freight schedules, operating at up to 1,500 V and 3,000 A with a rated maximum of 3.75 MW.
Fleet operators are already preparing for the electrification of driverless semis and planning for charging stations alongside autonomous vehicle (AV) deployment.
Removing the driver dramatically increases asset utilization; however, it relies on infrastructure reliably performing without human intervention or workarounds. For example, if an autonomous electric truck can’t complete a session on its own, it’s dead freight. That is driving investment in the Megawatt Charging System (MCS), a high-power standard designed for commercial electric vehicles.
Unlike electric passenger cars, which rely on the Combined Charging System (CCS) standard with power levels of around 350 kW, freight vehicles need significantly more power. MCS operates at up to 1,500 V and 3,000 A, with a rated maximum of 3.75 MW. This enables a long-haul truck to take on enough energy in under 45 minutes to cover its next shift, whether that window falls during a driver’s mandatory rest break or a scheduled stop on an autonomous route.
That changes the calculus on battery sizing. Instead of carrying a 1,000-kWh battery large enough to last an entire shift, big rigs can use a 450-kWh pack and recharge en route. Smaller batteries mean less weight, more payload capacity, and lower vehicle cost. The balance among battery size, vehicle weight, and charging speed makes the economics of electric long-haul freight viable.
The engineering challenges are extensive. Liquid-cooled cables and connectors must manage enormous thermal loads during repeated high-duty sessions. Software reliability spans ISO 15118-20 and automotive Ethernet communication protocols. Interoperability must work across an ecosystem with multiple manufacturers developing MCS-compliant systems. And all of this must integrate with grids that vary in capacity, stability, and permitting complexity.
Despite these challenges, megawatt charging delivers more power per square meter of site footprint than alternative heavy-duty charging approaches, which is why it’s the leading candidate for high-volume freight corridors.
Standards and the infrastructure gap
Building this out will require significant capital. McKinsey estimates that infrastructure across the US and Europe will need $30 billion by 2035. A single megawatt charger may need a dedicated substation-level grid connection.
An array of MCS charging stations must sustain repeated high-power sessions across heavy-duty fleet operations.
The European Automobile Manufacturers’ Association (ACEA) anticipates that Europe will require 40,000 to 50,000 high-power public points by 2030, plus at least 270,000 depots. Only a fraction of that investment has been committed.
There has been progress, with two critical milestones recently met. The SAE J3271, released in March 2025, provides system-level specifications for MCS across electromechanical couplers, communications, cooling, and interoperability testing. More recently, IEC TS 63379 established globally recognized hardware specifications for connectors, inlets, and cable assemblies.
CharIN, the global industry association coordinating standards, has incorporated MCS testing into its regular Testival program.
Standards provide a framework, but compliance alone doesn’t guarantee real-world performance. Field conditions introduce variables that lab testing can’t fully replicate. Closing the gap requires test environments that combine hardware-in-the-loop emulation with software-defined scenarios to replicate failure modes that only occur under operating conditions.
Why testing is throttling progress
Every element of megawatt charging carries risks that can only be identified and resolved through rigorous testing and validation. For autonomous freight, the stakes are higher. Without a driver to intervene when a session fails, aborts, or behaves unexpectedly, the system must handle every edge case. That calls for validation not just of individual components but of the complete ecosystem, from connector to cloud, under scenarios that mirror operational reality.
These include EV/EVSE interoperability, ISO 15118 and DIN SPEC 70121 communication, charging session start and stop behavior, CP/PP signaling and signal integrity, dynamic load changes, long-duration charging, and fault-injection and recovery testing. Verification against IEC 61851-23-3 is the starting point, while EV-emulation and EVSE-emulation scenarios confirm correct behavior on both sides of the coupler.
Test programs must measure:
- Voltage and current (dc)
- Power and efficiency
- Contact resistance
- Voltage drop across charging contacts
- Insulation resistance and leakage current
- Coolant temperature, flow, and pressure drop
- Temperatures across the connector, cable, inlet, and power electronics
- Communication timing and protocol behavior
At sustained high current, the focus should shift to voltage stability, current ripple, transient response, temperature rise, thermal gradients, long-term thermal stability, and cooling efficiency.
MCS validation must confirm that charging remains reliable during sustained high-current operation in real-world conditions.
Validation should cover protocol conformance across manufacturers and regions, fault handling during rushed coupling, adverse weather, and partial failures, and grid response under variable load and ramp conditions. Interoperability, component aging, and the durability of safety mechanisms matter over the full lifecycle.
Companies that invest in comprehensive test and validation will bring reliable, standards-compliant systems to market faster. Those who treat testing as a final checkbox risk costly redesigns, delays, field failures, and lost trust in a market where confidence in infrastructure is already fragile.
The road to autonomous, zero-emission freight doesn’t pass through megawatt charging; it runs on it. With trucking timelines and MCS deployment converging, the industry has a narrow opportunity to get testing right. As standards mature, infrastructure scales, and autonomy advances, the systems that earn fleet operators’ confidence will be the ones validated against real operating conditions.
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