Tesla V4 Supercharger Powers Semi Trucks and Electric Vehicles

The first Tesla V4 cabinet Superchargers are now live.

They have 0.5 MW, 3X power density and 2X stalls per cabinet.

It takes AC power in and uses 16 trays of power electronics and gives DC power out.

This is the tech that will make 1.2MW charging for Semi, and 0.5 MW charging for cars, ubiquitous around the world.

Higher throughput, higher efficiency, lower cost, faster deployments.

Tesla already had the most reliable and most powerful charging in the world.

This V4 supercharging takes it to another level.

The Tesla V4 Supercharger signifies a major step forward in EV charging topology, specifically engineered to meet the heavy-power needs of applications like the Tesla Semi while remaining compatible with passenger cars. At the heart of the V4 cabinet is a modular “masterpiece” as described—accepting AC from the grid, containing 16 swappable trays of power electronics for DC conversion and distribution, and delivering high-voltage DC output. This architecture enables remarkable scalability: a single cabinet can provide up to 1.2 MW for Semis (allowing a full recharge in under 2 hours for a typical 500–1,000 mile daily range) and 500 kW for cars, doubling the power density of V3 cabinets. Unlike V3’s four-stall limit per cabinet, V4 supports up to eight stalls, cutting civil works, cabling, and land needs by about 50% per stall while lowering deployment costs. The modular trays can be hot-swapped for maintenance or upgrades, delivering 99.9%+ uptime—vital for fleet operations.

From an energy and grid standpoint, V4’s pairing with Tesla’s Megablock (a pre-assembled 20 MWh AC battery system that bundles four Megapacks, medium-voltage transformers, and switchgear) tackles critical bottlenecks in broad deployment. Megablock reaches 91% round-trip efficiency at medium voltage (up to 35 kV), enabling “plug-and-play” installs in 23% less time and with 40% lower site costs versus conventional arrangements.

It smooths peak demand (e.g., 10–20 Semis charging at once at a depot), stabilizing the grid by importing during off-peak and exporting stored energy during peaks—potentially offsetting 20–30% of a site’s load. Medium-voltage transformers (15–35 kV) permit direct substation connections without extensive low-voltage upgrades, shortening interconnection queues from 12–18 months to 3–6 months in constrained regions like California or Texas.

This is disruptive for infrastructure: one Megablock can back 16–20 V4 cabinets, powering a 20-stall Semi depot drawing roughly 24 MW peak, with daily throughput for 100+ trucks.

For the Tesla Semi specifically, V4 enables widespread adoption by unifying passenger and truck charging networks. Semis need ~1.6 kWh/mile efficiency (real-world tests show 1.55 kWh/mile over 4,500 miles), equating to 800–2,000 kWh/day for near-continuous 23-hour operations (1,000–1,300 miles at a 55 mph average). At 1.2 MW, that translates to 40–100 minutes per charge, allowing depots to cycle trucks 5–6 times per day. The US freight sector (~3.5 trillion ton-miles/year) could indeed require 3 million Semis for full electrification, as autonomy (no driver breaks, platooning) increases utilization 2–3x versus diesel rigs, cutting emissions by 80%+ and reducing energy costs to $0.10–0.15/kWh off-peak. V4/Megablock combinations make this possible by deploying “mega-stations” (50+ stalls) along I-80/I-10 corridors, with bidirectional grid services producing revenue to help finance builds.

Tesla can upgrade ~70% of existing V3 Superchargers (15,000+ NA stalls as of late 2025), speeding deployment. V4 cabinets attach to V3 pedestals with minimal trenching (adding liquid-cooled cables for 1,000V/615A), enabling 250–500 kW car charging today and Semi retrofits via software/firmware. This leverages the network’s 60,000+ global stalls, avoiding greenfield permitting delays.

Infrastructure Costs: V4 Installs, Upgrades, and Supporting Systems

Using 2025 figures, Tesla’s V4 rollouts achieve industry-leading economies of scale. New V4 stall installs average $35,000–$40,000 per stall, covering cabinet, pedestal, cabling, and basic civil works—down from V3’s ~$43,000 because of modular trays and shared Megapack components. This includes about $15,000 for hardware and $20,000–$25,000 for site prep (trenching, permitting). For full sites (e.g., 12–20 stalls), add $200,000–$500,000 in grid connections and land leases.

Upgrades from V3 to V4 are much cheaper at $15,000–$25,000 per stall, mainly involving cabinet swaps (~$10,000) and cable retrofits ($5,000–$10,000), with no major civil works required at over 80% of sites. Tesla aims for 20–30% annual upgrade rates, saving $10,000–$20,000 per stall versus new builds.

For Semi-specific infrastructure, costs rise to about $500/kW installed due to the higher power (1.2 MW/stall), amounting to $400,000–$600,000 per Megacharger stall (including liquid-cooled high-voltage lines). A 20-stall depot totals $8–12M, but V4 hybrids cut this by 30–40% through shared cabinets. Megablocks add $6–7M per 20 MWh unit ($300–$350/kWh installed, including medium-voltage transformers at $500,000–$1M each), with full-site permitting and interconnection at $100,000–$300,000. Other expenses: annual O&M ~$1,000/stall (5% of capex), offset by $0.30–$0.50/kWh revenue. Total network capex for 2026–2028 projections: $8–12B, about 20% lower than prior estimates thanks to V4 efficiencies.

Rollout Projections for 2026–2028: Supporting Semi and Robotaxi Charging

Key assumptions: Semi fleet: Starts at 50,000 units in 2026 (Nevada factory full ramp), cumulative 100k (2027), 150k (2028). Daily energy: 1,600 kWh/truck (1,000 miles at 1.6 kWh/mile, autonomous 23/7 ops).

Robotaxi demand: Unsupervised FSD enables 40,000–60,000 miles/year/vehicle (2–3x the typical 15,000–20,000 miles/year private use). Efficiency: 3–4 miles/kWh (0.25–0.333 kWh/mile), producing 13,300–15,000 kWh/year per car (avg. 14,600 kWh). Fleet scales: 500k vehicles (2026), 2M (2027), 5M (2028).

Total energy: 7.3 TWh/year (2026), 29.2 TWh (2027), 73 TWh (2028)—mainly overnight/urban depots at 250–500 kW.

Fleet scales aggressively: 500k vehicles (2026, mix of owner-opted Model 3/Y + initial Cybercab), 2M (2027), 5M (2028).

Per-vehicle energy: 30–50 kWh/day extra (2x utilization), totaling 20–30 TWh/year network-wide by 2028.

Infrastructure baseline: NA Supercharger network at 20,000 stalls end-2025 (10% YoY growth to date). V4 adoption: 50% of new builds. Megachargers start private, go public 2027. Upgrades: 20–30% of V3 sites/year.

Constraints/mitigations: Grid queues eased by Megablock’s medium-voltage step-up. permitting 6–9 months/site. Costs as above. revenue offsets 20–30% of capex.

Total demand: Semis add 8–24 TWh/year. Robotaxis add 7–73 TWh/year.

For 100 TWh/year Total capacity increase: 24.82 GW (solar) + 9.56 GW (natural gas) ≈ 34 GW. If it was a mix. Solar has 24% capacity factor and gas has about 60%.

Projections focus on practical V4/Megablock rollouts to reach 95%+ coverage for high-utilization fleets (e.g., 300-mile radius access). Rollout speeds up via modular factories (Shanghai/Lathrop scaling Megapacks 2x/year) and NACS adoption (doubling utilization).

This path positions Tesla to capture 20–30% of NA freight by 2028, with V4/Megablock lowering total infrastructure capex to $8–12B (vs. $25B+ without modularity). Risks include supply chain (lithium/copper) and regulatory (FSD approval), but grid resilience via storage makes it feasible—potentially adding 1–2% to US peak demand while cutting freight CO2 by 15–20 Mt/year.