The Megawatt Charging System (MCS) is a next-generation DC fast-charging standard engineered for heavy-duty electric vehicles (HDVs) — Class 6, 7, and 8 trucks, electric buses, off-highway equipment, and marine vessels. Capable of delivering up to 3.75 MW of continuous DC power (3,000 A at 1,250 V DC), MCS is the charging infrastructure layer that makes long-haul zero-emission trucking commercially viable at scale.
This glossary provides authoritative, technically accurate definitions of every key term, standard, and component associated with MCS — written for charge point operators (CPOs), fleet infrastructure planners, electrical engineers, and procurement professionals. All technical claims reference primary sources: CharIN, IEC, SAE International, NREL, and the U.S. Department of Energy.
Related on this site: Electric Truck Charging Trends in 2026 | The Rise and Future of DC EV Chargers | EU Commercial Vehicle EV Trends Q1 2025
Table of Contents
1. What Is the Megawatt Charging System (MCS)?
The Megawatt Charging System (MCS) is a conductive DC charging system standardized for heavy-duty electric vehicles. It was developed by the Charging Interface Initiative (CharIN e.V.) — the same international industry consortium behind the Combined Charging System (CCS) — beginning with the formation of the MCS Task Force in 2018.
MCS addresses a fundamental limitation of existing fast-charging technology: current CCS-based DC fast chargers reach a practical ceiling of 350–500 kW, which is insufficient to charge the 400–1,000+ kWh battery packs found in Class 8 semi-trucks within commercially viable time windows. A Class 8 truck with a 600 kWh battery pack requires 1–2 hours on a dual-gun 300 kW DC fast charger — an unacceptable downtime for long-haul operations. MCS changes this equation by compressing the same charge to under 30–45 minutes, aligning with mandatory EU driver rest breaks under EC Regulation 561/2006.
The MCS standard is designed as a holistic system approach that covers the connector, cable, vehicle inlet, EVSE hardware, communication protocol, and safety architecture — all within a single, globally interoperable framework.
Origin & Development Timeline
| Year | Milestone | Source |
|---|---|---|
| 2017–2018 | CharIN forms the High-Power Charging for Commercial Vehicles (HPCCV) working group; initial requirements approved by CharIN Board in November 2018 | CharIN |
| 2020–2021 | Five candidate connector designs submitted (Tesla, Electrify America, ABB, paXos, Stäubli); MCS connector v3.2 adopted December 2021 | Wikipedia / CharIN |
| Spring 2021 | IEC begins development of standard IEC 63379 for MCS connectors | Wikipedia |
| December 2021 | SAE International begins drafting SAE J3271 requirements for North American MCS implementation | SAE International |
| November 2022 | CharIN publishes MCS White Paper v1.0 — technical recommendations for EVSE manufacturers | CharIN |
| May 2025 | CharIN publishes MCS White Paper v2.0 with updated EMC, thermal, and V2G recommendations | CharIN / Mobility Portal |
| February 2026 | IEC TS 63379 officially published — global technical specification for MCS connectors, inlets, and cable assemblies | CharIN |
2. Governing Standards: IEC TS 63379, SAE J3271, IEC 61851-23-3, ISO 15118-20
MCS does not rest on a single document. It is governed by a multi-standard framework spanning hardware, power electronics, safety, and communication — developed in parallel across IEC, ISO, and SAE. Understanding each layer is essential for procurement, infrastructure planning, and regulatory compliance.
IEC TS 63379 — Connector, Inlet & Cable Assembly Specification
IEC TS 63379 is the primary international technical specification governing the MCS hardware interface — specifically the connector geometry, vehicle inlet, and cable assembly for conductive DC charging at megawatt power levels. Published officially by the International Electrotechnical Commission (IEC) in February 2026, it defines:
- A 7-pin connector architecture rated up to 1,500 V DC (system operating range: 500–1,250 V DC)
- Maximum continuous current rating of 3,000 A DC
- Touch safety requirements per IEC 60529 (IPXXB finger-probe protection on unmated connector)
- Liquid-cooled cable and connector assembly specifications
- Automated locking mechanism and optional robotic interface compatibility
Note: IEC TS 63379 is a Technical Specification (TS), not yet a full International Standard (IS). It serves as the normative reference during the current commercialization phase, with full IS adoption expected in subsequent revision cycles.
SAE J3271 — North American MCS Requirements
SAE J3271 is the SAE International Technical Information Report (TIR) that harmonizes MCS requirements for the North American market. Development began December 2021, and it covers:
- Coupler geometry and mechanical interface (aligned with IEC TS 63379)
- Cable cooling specifications (liquid-cooled)
- Communication requirements (ISO 15118-20 / IEC 61851-23-3)
- Interoperability and safety requirements from grid connection point to vehicle inlet
- Differential signaling over twisted-pair wiring (replacing CCS power line communication)
SAE J3271 is harmonized with IEC 61851-23-3 and is intended to ensure that MCS-equipped trucks and EVSE from different manufacturers can interoperate without custom engineering across the US and Canadian markets.
IEC 61851-23-3 — EVSE System Requirements for MCS
IEC 61851-23-3 is the IEC standard that extends the IEC 61851 series (DC EV charging station requirements) to cover MCS-class power levels. It defines the electrical safety, output accuracy, metering, and operational requirements for the charging station (EVSE) side of the MCS interface — complementing IEC TS 63379’s hardware specifications. Key provisions include:
- Minimum supported current: 0 A (allowing communication to continue without active energy transfer, supporting future V2G capability)
- Energy metering accuracy class (OCMF-compatible digital output, encrypted and digitally signed)
- Fault detection: insulation monitoring, arc detection, and overvoltage/overcurrent protection
- Electromagnetic compatibility (EMC) requirements per IEC 61851-21-2
ISO 15118-20 — Vehicle-to-Grid Communication (V2G/Plug & Charge)
ISO 15118-20 (published 2022, with Amendment 1 / Annex K for MCS service in 2024) is the international communication standard that governs the data exchange between the MCS-equipped EV and the EVSE. It replaces the power line communication (PLC) used in CCS with automotive Ethernet (IEEE 10BASE-T1S), enabling:
- Plug & Charge (PnC) — automated authentication and billing without RFID or app interaction
- Smart charging — real-time negotiation of charging current/voltage based on vehicle state-of-charge, grid load, and pricing signals
- Vehicle-to-Grid (V2G) — bidirectional power flow for grid services (requires optional UPS at EVSE if no low-voltage auxiliary supply in connector)
- High-speed session setup — sub-60ms latency requirement for communication packets
3. MCS Connector & Inlet
The MCS connector is the physical interface between the charging cable and the vehicle’s inlet port. It was designed from the ground up for megawatt-class power transfer and differs fundamentally from CCS1, CCS2, and NACS connectors in its architecture, pin count, cooling integration, and locking mechanism.
Connector Architecture
| Parameter | Specification | Source |
|---|---|---|
| Standard designation | MCS IEC-63379 (also referenced as IEC TS 63379) | CharIN / IEC |
| Pin count | 7 pins | Wikipedia / IEC |
| DC power pins | 2 (DC+, DC−) | CharIN |
| Protective earth pin | 1 dedicated PE pin | CharIN |
| Communication | ISO 15118-20 over 10BASE-T1S Single Pair Ethernet | CharIN |
| Designed voltage rating | 1,500 V DC (system operating range: 500–1,250 V DC) | CharIN White Paper |
| Maximum continuous current | 3,000 A DC | CharIN White Paper |
| Touch safety (unmated) | IPXXB per IEC 60529 — no high-voltage exposure when unmated | CharIN / IEC 60529 |
| Locking mechanism | Automated; optional robotic charging interface compatibility | Keysight |
| Cooling | Liquid-cooled cable and connector (active cooling required at currents above ~1,000 A) | CharIN White Paper v2.0 |
| Cable length (typical) | ~2 m (per CharIN interoperability test configuration) | eMobility Engineering |
Vehicle Inlet
The MCS vehicle inlet is the receptacle mounted on the heavy-duty vehicle. CharIN strongly recommends that all MCS EVSEs support the full operating voltage range of 500–1,250 V DC to ensure maximum interoperability with vehicles currently in development. Restricting EVSE to a narrower voltage window (e.g., 750–1,000 V) risks creating de-facto incompatibility with certain OEM vehicle designs, repeating fragmentation issues seen in early CCS adoption.
Ergonomics & Manual Handling
Despite the extreme power ratings, the MCS connector is designed to be manageable by a single driver for manual use, with an ergonomic handle and weight balanced for the approximately 2 m cable assembly. Automated robotic charging interfaces are supported as an optional feature for depot environments where drivers do not need to manually connect the charger — relevant for yard trucks, autonomous freight applications, and round-the-clock fleet operations.
4. Electrical Parameters: Voltage, Current, Power
The electrical architecture of MCS is defined by three primary parameters — voltage window, maximum current, and resulting peak power — all specified in the CharIN White Paper (v1.0, 2022; v2.0, 2025) and codified in IEC TS 63379 and IEC 61851-23-3.
Operating Voltage Range
The nominal operating voltage window for MCS is 500–1,250 V DC. This range accommodates the battery architectures of current and near-future Class 6–8 vehicles, which typically operate at 600–1,000 V nominal pack voltage. The connector itself is rated to 1,500 V DC to provide adequate safety margin.
Why 1,250 V DC maximum?
This ceiling reflects the intersection of (a) battery pack voltages achievable in heavy-duty vehicles within this decade, (b) existing electrical safety standards for insulation and arc management at DC voltages, and (c) the thermal limits of liquid-cooled cable assemblies at very high currents. A 1,500 V DC extension (under consideration for future variants) would reduce current requirements proportionally, easing thermal management at equivalent power levels.
Current & Power Envelope
| Metric | Value | Notes |
|---|---|---|
| Maximum continuous current | 3,000 A DC | Tested; active liquid cooling required. Source: CharIN White Paper |
| Minimum current | 0 A (communication maintained) | Enables V2G operation; per IEC 61851-23-3. Source: CharIN |
| Peak power (3,000 A × 1,250 V) | 3.75 MW | Theoretical maximum. Source: CharIN |
| Practical early-deployment power | 1.0–1.68 MW | Based on current pilot deployments; hardware and grid constraints. Source: EV Infrastructure News 2026 |
| CCS2 comparison (maximum) | 350–500 kW | ~7× lower than MCS peak. Source: ZERA |
| Charge time: 1,000 kWh battery | <30 min at 3.75 MW | Key operational metric for long-haul trucks. Source: Keysight |
| Charge time: 600 kWh @ 45 min (EU rest break) | ~800–900 kW sustained power needed | Practical operational requirement; aligns with EC 561/2006 rest break rules |
Short-Circuit Rating
The MCS cable assembly is specified to withstand a short-circuit current of 11 MA²s — a measure of let-through energy under fault conditions. This parameter defines the required cross-sectional area of the protective earth (PE) conductor and the overcurrent protection rating of the upstream EVSE circuit breaker. It is specified in the CharIN White Paper and incorporated into IEC 61851-23-3.
Galvanic Isolation
MCS is designed as a galvanically isolated charging system — the DC output circuit is electrically isolated from the AC grid. This is a mandatory safety requirement that applies to all state-of-the-art DC fast chargers per ISO 5474, IEC 60664, and the IEC 61851 series, and it is explicitly maintained in MCS despite the significantly higher power levels.
5. Thermal Management & Liquid-Cooled Cable
At 3,000 A of DC current, resistive (I²R) heat generation in the charging cable and connector becomes the principal engineering constraint. This is why MCS mandates liquid cooling for the cable assembly and recommends it for connectors and inlets operating above approximately 1,000 A — a requirement that sets it categorically apart from air-cooled CCS and NACS hardware.
Why Liquid Cooling Is Required
Electrical power loss in a conductor scales with the square of current (P = I²R). At 3,000 A, even a very-low-resistance cable will dissipate significant heat per meter of length. Without active thermal management, cable surface temperatures would rapidly exceed the limits of cable insulation materials (typically 90–105°C rated) and connector contact surfaces, creating safety risks including insulation degradation, contact welding, and arc flash potential at high voltages.
Cooling System Architecture
The MCS thermal management system uses a liquid coolant circulated through the cable and connector assembly. Two primary configurations are used in practice:
- Direct-cooled cables: Coolant flows in direct contact with the cable conductor. This maximizes heat extraction efficiency and allows thinner, lighter cable design with less copper. However, it requires careful fluid compatibility with conductor materials and more complex maintenance infrastructure.
- Indirect-cooled cables: Coolant flows in a jacket surrounding but not touching the conductor. Simpler construction and maintenance, but requires more conductor cross-section to manage heat passively.
Coolant fluid: Water-glycol mixtures are the preferred coolant for MCS applications. They offer efficient heat exchange, environmental acceptability, and compatibility with EV component materials. Oil-based coolants, while effective in high-voltage static applications, present higher infrastructure complexity for maintenance and disposal in mobile/dynamic environments. This is the recommendation stated in the CharIN-aligned MCS engineering guidance.
Responsibility Boundary: Vehicle vs. EVSE
CharIN White Paper v2.0 (2025) establishes a clear thermal responsibility boundary:
- The vehicle is responsible for monitoring inlet temperature and complying with temperature limits at the vehicle inlet interface.
- The EVSE is responsible for designing its output such that rated power is deliverable at ambient temperatures up to 40°C.
- The vehicle controls how much current is requested during charging via ISO 15118-20 — the EVSE communicates its current and voltage limits, but the EV determines the actual charge rate.
6. Communication Protocol: ISO 15118-20 & 10BASE-T1S Ethernet
MCS replaces the power line communication (PLC) protocol used in CCS with automotive Ethernet — specifically the IEEE 10BASE-T1S single-pair Ethernet standard. This architectural shift was driven by the higher data rates, lower latency, and greater electromagnetic noise immunity required at megawatt power levels.
Why PLC Cannot Scale to MCS
In CCS systems, the communication signal is superimposed on the pilot wire using power line communication (PLC), operating at relatively low data rates. At the current levels and cable lengths involved in MCS, PLC is vulnerable to electromagnetic interference (EMI) from the traction power circuit. CharIN members conducted validation tests using bulk current injection (BCI) techniques to simulate traction EMI, with a failure threshold defined as loss of a single data packet or latency exceeding 60 ms — an extremely stringent requirement that PLC cannot reliably meet at MCS power levels.
10BASE-T1S Single Pair Ethernet
10BASE-T1S is an IEEE automotive Ethernet standard that transmits at 10 Mbit/s over a single twisted pair. In MCS, it is used for the communication link between the EVSE and the vehicle, carrying ISO 15118-20 application-layer messages. Key attributes relevant to MCS:
- Differential signaling — inherently immune to common-mode EMI from high-current DC lines
- Supports multi-drop bus topology (allows a single cable pair to serve multiple devices)
- Low pin count — reduces connector complexity in the 7-pin MCS interface
- Strict latency requirements maintained per CharIN EMC testing (max 60 ms packet latency)
ISO 15118-20 Application Layer
The ISO 15118-20 standard (published 2022; Amendment 1 / Annex K for MCS service: 2024) defines the application-level messages exchanged between EVSE and vehicle, including:
- Service discovery — vehicle and EVSE negotiate supported charging services at session start
- Dynamic charge control — real-time current/voltage setpoint negotiation based on vehicle SoC, battery temperature, and grid/EVSE constraints
- Plug & Charge (PnC) — ISO 15118-defined PKI certificate exchange enabling contract-based automated authentication and billing without user interaction
- Vehicle-to-Grid (V2G) — bidirectional energy flow messages; requires optional UPS at EVSE when no auxiliary low-voltage supply is integrated in the MCS connector
- 0A mode — communication session can remain active while no energy is transferred (contactors open or closed), critical for V2G grid services and demand response
7. MCS vs. CCS2 vs. NACS: Key Differences
Understanding how MCS compares to existing charging standards is essential for infrastructure planning. The following table covers the parameters most relevant to fleet operators, CPOs, and EVSE procurement teams.
| Parameter | MCS | CCS2 (IEC 62196-3) | NACS / SAE J3400 |
|---|---|---|---|
| Target vehicle class | Class 6–8 trucks, buses, heavy off-highway | Passenger cars, light commercial | Passenger cars, light trucks (Tesla-origin; expanding to commercial) |
| Max voltage (DC) | 1,250 V (connector rated to 1,500 V) | 500–1,000 V | 1,000 V |
| Max continuous current | 3,000 A | 500 A | 600 A |
| Peak power | 3,750 kW (3.75 MW) | ~500 kW practical maximum | ~600 kW (at 1,000 V / 600 A) |
| Communication | ISO 15118-20 / 10BASE-T1S Ethernet | ISO 15118-2/20 / PLC | ISO 15118-20 / PLC (transitioning to Ethernet) |
| Cable cooling | Liquid-cooled (mandatory above ~1,000 A) | Air-cooled (liquid-cooled above 350 kW) | Air-cooled (liquid-cooled for V3 Supercharger) |
| Connector pins | 7 | 7 (Type 2 AC + 2 DC pins) | 3 |
| Governing standard | IEC TS 63379, SAE J3271, IEC 61851-23-3 | IEC 62196-3, IEC 61851-23 | SAE J3400 |
| V2G capability | Yes (ISO 15118-20, 0A mode) | Yes (ISO 15118-20 capable EVSEs) | Yes (ISO 15118-20 capable EVSEs) |
| Backward compatibility | No (new connector; not backward-compatible with CCS) | Type 2 AC compatible (with adapter) | Backward-compatible with Tesla vehicles |
| Primary markets | Global (CharIN/IEC international standard) | Europe, Brazil, Australia, Asia | North America (expanding globally) |
Key conclusion for planners: MCS is not a replacement for CCS2 or NACS in light-duty applications. It is an entirely separate charging layer designed specifically for heavy-duty commercial vehicles. Depot infrastructure for Class 6–8 fleets will need to accommodate both CCS2/NACS (for light commercial) and MCS (for heavy trucks) in parallel, requiring separate grid connection design for each circuit tier.
For JointCharging’s current DC fast charger portfolio (30–400 kW, CCS2 / CCS1 / NACS), see: DC fast chargers 30–400 kW (CCS2) and CCS1/NACS DC fast chargers for USA & Canada.
8. Compatible Vehicle Classes & Applications
MCS is explicitly scoped for vehicles where the battery capacity and operational duty cycle make sub-megawatt charging commercially impractical. CharIN’s specification document defines the primary target as Class 6, 7, and 8 commercial vehicles, with explicit extension to other large BEV applications.
Primary Target Vehicle Categories
| Vehicle Category | Examples | Typical Battery Capacity | Why MCS Is Needed |
|---|---|---|---|
| Class 8 long-haul semi-trucks | Volvo FH Electric, Daimler eActros LongHaul, Freightliner eCascadia | 600–1,000+ kWh | Requires 45-min charge window (EU driver break) for viable scheduling |
| Class 6–7 regional trucks | Volvo VNR Electric, Freightliner eM2 | 300–565 kWh | High daily utilization requires fast overnight depot turnaround |
| Electric buses (BRT/intercity) | High-capacity articulated and double-deck BEV buses | 300–600 kWh | Short layover windows between routes; depot opportunity charging |
| Port yard trucks & terminal tractors | Orange EV T-Series, Kalmar Ottawa T2E | 200–400 kWh | 24/7 operations; minimal opportunity charging windows |
| Mining haul trucks | Komatsu 930E-5, Epiroc MT65 | 1,000–2,000+ kWh | Extreme battery capacity; rapid shift-change charging essential |
| Electric aircraft ground support | Future electric ground power units (GPU) | Varies | CharIN has initiated MCS discussions for aviation ground operations |
| Marine / shore power | Battery-electric and hybrid ferries | Varies | IEC TS 63379 extended to harmonized marine shore-power applications |
9. Infrastructure & Grid Requirements
Deploying MCS-capable charging infrastructure represents a fundamentally different engineering challenge from light-duty fast-charging. The power levels involved — 1 MW and above per stall — require dedicated medium-voltage grid connections, purpose-built electrical infrastructure, and often, on-site energy storage to manage peak demand charges and grid constraints.
Grid Connection Requirements
- Medium-voltage (MV) grid connection: A single MCS stall operating at 1 MW+ requires a transformer and grid connection dimensioned far beyond the low-voltage service typical of passenger car charging sites. Multi-stall depots may require 10–50 MVA substation capacity.
- Grid planning timelines: In many European markets (notably the UK and the Netherlands), grid connection approval and construction timelines of 3–7 years represent the primary bottleneck for MCS deployment — not hardware availability. This is acknowledged in the European Alternative Fuels Observatory’s 2025 reporting.
- Battery energy storage systems (BESS): On-site BESS is increasingly deployed in conjunction with MCS to reduce peak grid demand, enable charging during grid-constrained periods, and integrate renewable generation. The U.S. DOE’s $68 million SuperTruck Charge initiative (January 2025) includes MCS-compatible sites specifically designed around BESS + solar integration to supplement constrained utility connections. For energy storage combined with EV charging infrastructure, see CE-certified energy storage with EV charging.
EVSE Power Architecture
MCS EVSEs typically use a modular, distributed power unit architecture: multiple rectifier/DC-DC converter modules — each rated at 50–250 kW — are aggregated and switched to individual charging outlets via a central power switching matrix. This architecture provides:
- Scalable power allocation between multiple simultaneous charging stalls
- Redundancy: failure of one power module reduces, but does not eliminate, available charging capacity
- Optimal efficiency: individual modules can be staged on/off to maintain operation near peak efficiency across a wide range of output power levels
- Integration of second-life stationary storage for peak shaving, reducing grid demand charges
Metering & Measurement
MCS imposes strict metering requirements derived from IEC 61851-23-3. DC power must be measured directly at the charging point (not on the AC input side), and measurement data must be digitally signed and transmitted in encrypted form using OCMF (Open Charge Metering Format). This is a prerequisite for legally compliant billing in regulated European markets.
10. MCS Variants: Standard MCS, R-MCS, X-MCS
While the standard MCS specification covers most heavy-duty vehicle applications, CharIN and the broader industry are developing extended variants for specialized environments requiring higher power levels or ruggedized hardware.
| Variant | Max Power | Max Current / Voltage | Target Application | Status |
|---|---|---|---|---|
| MCS (Standard) | 3.75 MW | 3,000 A / 1,250 V DC | Class 6–8 trucks, buses, highway corridors | IEC TS 63379 published Feb 2026 |
| R-MCS (Ruggedized) | Up to 6 MW | 4,000 A / 1,500 V DC | Mining haul trucks, heavy off-highway, maritime | Under development |
| X-MCS (Extended) | 12–24 MW | TBD | Future large mining equipment, aviation, industrial | Concept / future standard |
Source: Keysight EVSE Technology Overview
11. Regulatory Framework: AFIR, EU CO₂ Standards, US DOE
European Union: AFIR & CO₂ Targets
The EU’s Alternative Fuels Infrastructure Regulation (AFIR) (Regulation (EU) 2023/1804) establishes mandatory charging infrastructure targets for heavy-duty vehicles on the Trans-European Transport Network (TEN-T). Key AFIR requirements for heavy-duty charging:
- By 2025: Each highway charging pool must provide a minimum aggregate power of 400 kW, with at least one outlet of ≥150 kW
- By 2027: Minimum 600 kW per pool, with at least one outlet of ≥350 kW
- By 2030: Pools on the comprehensive TEN-T network must reach 1,200 kW aggregate — a threshold that implicitly requires MCS-class infrastructure
Simultaneously, the EU’s CO₂ emission standards for heavy-duty vehicles (updated 2025) require manufacturers to cut CO₂ emissions by 45% by 2030 and 90% by 2040 relative to 2019 baselines, with heavy financial penalties for non-compliance. This regulatory pressure directly drives OEM investment in battery-electric Class 8 platforms — and with them, demand for MCS infrastructure.
United States: DOE SuperTruck Charge & NEVI
The U.S. Department of Energy’s SuperTruck Charge initiative (announced January 15, 2025) committed $68 million to design, develop, and demonstrate innovative EV charging sites for medium- and heavy-duty vehicles near key ports, distribution hubs, and major freight corridors. Projects include MCS-compatible installations with integrated BESS and solar, specifically targeting the I-10 and I-15 freight corridors.
The National Electric Vehicle Infrastructure (NEVI) program ($5 billion allocated) covers primarily light-duty corridor charging; dedicated heavy-duty MCS infrastructure funding is channeled through SuperTruck Charge and separate FHWA programs. By end of 2024, approximately $30 million of NEVI funding had resulted in operational charging points — underscoring the pace challenge in heavy-duty corridor deployment.
12. MCS Deployment Status (2025–2026)
MCS has moved from prototype to early commercial deployment during 2025–2026, with the first operational corridor sites appearing in Europe and pilot sites in North America. The following are documented deployments and program milestones from official and industry sources.
Europe
- Milence MCS corridor (Europe): Milence — the joint venture between Daimler Truck, TRATON Group, and Volvo Trucks — is building Europe’s first MCS-dedicated charging corridor, with sites at Landvetter (Sweden) and additional locations. Power Electronics MCS units deliver up to 1,440 kW (1,000 V / 1,500 A). On these chargers, trucks such as the Volvo FH Aero Electric can charge from 20% to 80% SoC in 30–45 minutes.
- MAN / Duvenbeck / Hillert A2 corridor pilot (Germany, October 2025): A real-world logistics pilot along the A2 motorway — one of Europe’s core freight routes — testing MCS in daily operations with the MAN eTGX Ultra Low Liner, with Duvenbeck planning expansion to 100+ e-trucks by 2026.
North America
- DOE SuperTruck Charge sites (from 2025): Multiple MCS-compatible sites along I-10 and I-15 corridors, including BESS + solar integration. Awarded January 2025; targeted operational 2026–2027.
- Argonne National Laboratory interoperability testing: Eight MCS cable and inlet manufacturers are participating in coordinated communication interoperability testing at Argonne — validating that couplers and inlets from different suppliers communicate correctly via ISO 15118-20 before commercial deployment.
- EVSE manufacturer pipeline: Approximately 18 EVSE manufacturers are developing SAE J3271 MCS-compliant charging stations, largely as higher-power extensions of their existing CCS product lines.
Market Context
In 2024, American companies deployed more than 15,000 medium- and heavy-duty electric vehicles — including battery-electric semitrucks, passenger buses, and delivery vans — establishing the commercial demand base that MCS infrastructure is being built to serve.
14. Frequently Asked Questions About MCS
What is the Megawatt Charging System (MCS), and why was it developed?
MCS is a DC fast-charging standard developed by CharIN specifically for Class 6–8 heavy-duty electric trucks, buses, and other large commercial vehicles. It was developed because existing CCS-based chargers (maximum ~350–500 kW) cannot charge the large battery packs in commercial trucks (typically 400–1,000+ kWh) within commercially viable time windows. MCS supports up to 3.75 MW — approximately 7× the power of the fastest current passenger-car chargers — enabling a Class 8 truck with a 600 kWh battery to charge from 20% to 80% within the standard 45-minute EU driver rest break.
What is IEC TS 63379 and when was it published?
IEC TS 63379 is the primary international technical specification governing the MCS connector, vehicle inlet, and cable assembly hardware. It was officially published by the International Electrotechnical Commission (IEC) in February 2026, following a development process initiated by CharIN and the IEC standards committee beginning in Spring 2021. It defines connector geometry, pin count (7 pins), maximum operating voltage (1,250 V DC), maximum current (3,000 A), and safety requirements including IPXXB touch protection.
Is MCS compatible with CCS2 or NACS vehicles?
No. MCS uses a completely different connector, cable architecture, and communication protocol from CCS2, CCS1, and NACS. MCS connectors are not backward-compatible with any current passenger-car charging standard. MCS is a parallel standard targeting a different vehicle segment — heavy commercial trucks and buses — rather than a replacement for CCS or NACS in passenger cars or light commercial vehicles. Depot infrastructure planning for mixed fleets must account for both MCS (for Class 6–8 trucks) and CCS2/NACS (for lighter vehicles) in separate charging circuits.
Why does MCS require a liquid-cooled cable?
At the maximum MCS current of 3,000 A, resistive heat generation in the cable conductors would exceed the thermal limits of air-cooled cable insulation materials at any practical cable cross-section and length. Liquid cooling — using a water-glycol mixture circulated through the cable assembly — is the only engineering approach that makes it possible to deliver 3,000 A continuously through a cable that is light enough and flexible enough for a driver to handle manually. Active cooling is specified as mandatory in CharIN’s MCS White Paper for currents above approximately 1,000 A.
What are the grid connection requirements for an MCS charging site?
A single MCS charging stall operating at 1–1.5 MW requires a dedicated medium-voltage (MV) grid connection and step-down transformer dimensioned for that load plus future expansion. Multi-stall MCS depots may require 10–50 MVA substation capacity — comparable to a small industrial facility. Grid connection planning timelines in Europe frequently run to 3–7 years, making early engagement with the distribution system operator (DSO) the most critical first step in MCS infrastructure projects. Battery energy storage systems (BESS) are increasingly integrated to reduce peak grid demand and enable deployment where full grid capacity is not immediately available.
Looking for DC fast-charging solutions for your current heavy-duty fleet or depot? Joint’s DC fast chargers (30–400 kW, CCS2) and CCS1/NACS chargers for North America provide the proven infrastructure layer for Class 4–6 commercial fleet depots today, with energy storage integration options for sites requiring grid peak management: CE-certified energy storage with EV charging.
