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High-Voltage EV Charging: What Happens on 400V and 500V Fast Chargers

Last verified October 29, 2026

Re-verification overdueThis guide remains available for context but is not presented as current until it is rechecked.

An 800V label does not tell you how an EV will behave on a lower-voltage fast charger. Some high-voltage EVs boost lower-voltage input through existing drive electronics, some use a dedicated booster/charging module, and some manufacturers publish a lower-voltage power cap without publicly stating the conversion method.123456

This guide separates three things that are often collapsed together: the vehicle's battery/charging architecture, the charger's output voltage, and the power the vehicle can actually accept in that lower-voltage state. A missing vehicle means not verified here yet, not that it lacks lower-voltage charging support.

Compatibility matrix

EV / source scope Architecture / OEM-stated voltage Lower-voltage DC support Conversion method established by OEM OEM-stated lower-voltage state OEM-stated high-voltage state Important boundary
Hyundai IONIQ 5 — MY2026 U.S. 800V-class E-GMP; Hyundai lists 523V for the 63-kWh battery and 697V for the 84-kWh battery.1 Yes — 400V charging is explicitly documented.1 Motor/inverter boost at the E-GMP platform level. Hyundai says the motor and inverter boost 400V input to 800V.2 Hyundai's U.S. spec table uses a 150-kW / 400V NACS test condition: 10–80% in about 24 minutes for the 63-kWh battery and 30 minutes for the 84-kWh battery.1 The same table lists 10–80% in about 20 minutes with the included CCS adapter on >250-kW / 800V equipment.1 The 150-kW figure is the published test condition, not a separately stated vehicle-side 400V maximum. The exact 2026 U.S. page and the older E-GMP mechanism source are paired rather than treating the platform release as a current trim sheet.
Porsche Taycan — current MY2027 U.S. family + current Porsche technical press kit Porsche's current U.S. Taycan page identifies 800V battery technology and up to 320 kW charging on applicable variants.7 Yes — 400V charging is explicitly supported in Porsche's current technical documentation.3 Combined Booster Charger (CBC). Porsche's current press kit says the CBC replaces the DC/DC converter and first-generation HV booster.3 Up to 150 kW at 400V charging points, with about 35 minutes in Porsche's described lower-voltage charging state.3 Up to 320 kW at 800V charging points.37 Porsche's February 2024 MY2025 launch release used the earlier wording 150-kW DC/DC converter.8 The current CBC description governs this row; the older wording is historical context, not the current component label.
Lucid Gravity Grand Touring — MY2026 U.S. 926V battery pack.4 Yes — 500V-class charging is explicitly supported.4 Rear motor drive-unit boost. Lucid says the rear drive unit boosts 500V input to match the 926V pack.4 Lucid states sustained speeds up to 225 kW on 500V-architecture fast chargers, including Tesla V3 Superchargers.4 Up to 400 kW on 1000V equipment.4 The 225-kW and 400-kW figures are manufacturer-stated charging capabilities, not guaranteed real-world rates at every compatible station.
Mercedes-Benz CLA — MY2026 U.S., factory-converter status must be verified Mercedes describes an 800V DC architecture for the 2026 CLA 250+/350.9 Condition-dependent: a 2026 CLA without the factory 400V converter is described by Mercedes as 800V-DC-only; a factory-converter-equipped CLA (offered starting Spring 2026) supports 400V DC.9 Factory-installed 400V converter, where fitted. Mercedes does not establish a universal owner retrofit.9 No 400V-specific maximum verified for the exact 2026 build; not applicable for vehicles lacking the converter.9 800V DC charging described by Mercedes; no 2026-specific rated number is borrowed from the separate 2027 specs.9 Check the actual VIN/equipment with Mercedes or dealer before treating a 2026 car as 400V capable. Factory converter, connector shape and Tesla permission are separate decisions. A MY2027 specification cannot certify a MY2026 build.910
Mercedes-Benz CLA 250+ / CLA 350 4MATIC — MY2027 U.S. Mercedes' 2027 U.S. charging page identifies 800V and 400V DC capability for the CLA.11 Yes — 400V DC supported at manufacturer/model level. Confirm individual equipment, actual charger conditions and site authorization.1110 Exact MY2027 conversion hardware mechanism not separately detailed in the reviewed model pages. Earlier MY2026 material specifies a factory 400V converter; do not equate the different model-year evidence.911 400V-specific kW ceiling not established. The 320-kW overall DC figure is not a 400V rating.111213 320 kW general DC charging specification for each 2027 U.S. CLA model; Mercedes' 22-minute 10–80% best-case claim is not a 400V guarantee.1213 J1772 AC and native NACS DC are separate vehicle interfaces. Mercedes describes a CCS1-compatible DC adapter for 2027 native-NACS EVs; Tesla support is restricted to live compatible sites, not every Supercharger.11121310
Mercedes-Benz GLC 400 4MATIC Electric — MY2027 U.S. Mercedes-Benz publishes an 800V DC charging state on the current U.S. model page.5 Yes — a 400V charging state is explicitly listed.5 Not established in the checked current U.S. model page. 100 kW at 400V.5 330 kW at 800V.5 Do not infer a booster, converter or pack-switching method merely from the two published power figures.
Mercedes-Benz EQS 450+ Sedan — MY2027 U.S. Mercedes-Benz publishes an 800V DC charging state on the current U.S. model page.6 Yes — a 400V charging state is explicitly listed.6 Not established in the checked current U.S. model page. 175 kW at 400V.6 350 kW at 800V.6 Mercedes' 2027 EQS model page lists a NACS DC connector, but Mercedes' general 2027 charging overview says EQS has a CCS1 DC inlet. This unresolved manufacturer-page conflict concerns the connector, not the separately listed 400V/800V power states. Confirm the actual vehicle inlet with Mercedes/dealer; do not infer it from this matrix.611

Mercedes-Benz CLA: 2026 converter, 2027 voltage and actual Supercharger access

The U.S. CLA's 400V DC charging answer depends on the vehicle's equipment and model-year evidence, not on its NACS-shaped DC inlet. Mercedes' earlier MY2026 product FAQ warns that CLAs without a factory-equipped 400V converter can DC fast charge only at compatible 800V stations; it describes factory converters becoming available starting Spring 2026. Its current MY2027 U.S. charging page, by contrast, describes the CLA as supporting both 400V and 800V DC fast charging.911

Check before buying or planning a charging stop Evidence-based decision
1. Identify the actual 2026 or 2027 car. MY2026: ask Mercedes/dealer to confirm the exact VIN's factory converter; the model-year label alone does not prove it is fitted. MY2027: Mercedes' current U.S. CLA model-level description includes both voltage classes; confirm actual equipment/charging conditions when needed.911
2. Distinguish voltage from advertised peak power. Mercedes lists 320 kW overall DC for both 2027 U.S. CLA 250+ and 350 4MATIC, but the checked model and charging pages do not separately specify a 400V-side kW maximum or 400V charge curve. Do not interpret 320 kW as the rate at a lower-voltage DC station.111213
3. Use the correct charging interface. 2027 U.S. CLA specs explicitly identify J1772 for AC Level 1/2 and a native NACS inlet for DC fast charging. For a CCS1-cable DC charger, Mercedes says its 2027 native-NACS EVs include a compatible DC adapter. This is not a J1772 AC adapter, nor proof that all 2026 used cars include every accessory.9111213
4. Check the actual Tesla site. Tesla lists Mercedes-Benz as a manufacturer enabled at select NACS Superchargers, but a Tesla-only stall remains unavailable and supported sites vary by vehicle. Select your exact EV and station in Tesla's live app/map and confirm charging/payment setup; neither 400V capability nor a native NACS plug grants all-station access.10

For Tesla-only/All-EV/Magic Dock/manufacturer-enabled station classes and network activation details, see ATC's non-Tesla Supercharger and NACS compatibility guide. For interpreting best-case charging-time and power numbers, see EV DC fast-charging times. No universal MY2026 retrofit, 400V kW ceiling, 400V charge curve, every-VIN capability or every-Tesla-site entitlement is established by this check.

Hyundai IONIQ 5: 2025 maximum claim versus 2026 test-charger figure

These are different kinds of numbers, not evidence that the 2026 IONIQ 5 has a 150-kW vehicle-side limit or that Hyundai changed a 135-kW cap. Hyundai's U.S. model-year-specific sources describe two different things: a 2025 vehicle “up to” claim for Tesla Superchargers, and 2026 charging-time tests conducted with specified charger power and voltage.141

U.S. vehicle / charging path Manufacturer's figure What the number describes What it does not establish
2025 IONIQ 5 at an eligible Tesla Supercharger Up to 135 kW under ideal conditions.14 Hyundai's vehicle/model-year-scoped maximum claim on its 2025 owner FAQ. Actual speed varies with battery temperature, state of charge, station conditions and other factors.14 Not a guaranteed delivered rate, a limit for the 2026 model or a statement about every Supercharger.
2026 IONIQ 5 using NACS at 400V 150-kW / 400V charger test; 10–80% in about 24 minutes (63-kWh pack) or 30 minutes (84-kWh pack).1 Hyundai's charger/test-condition figure associated with its stated charging-time benchmarks. Not a separately published maximum actual vehicle acceptance power in this checked Hyundai table; not proof that a particular 150-kW charger will deliver 150 kW.
2026 IONIQ 5 using the specified CCS adapter at higher-voltage DC equipment Greater-than-250-kW / 800V charger test; about 20 minutes from 10–80% for either listed pack.1 A different higher-voltage manufacturer test condition, not the lower-voltage NACS measurement. Not a guarantee of 20 minutes at an arbitrary public charger or proof that connector shape alone determines charging speed.

Measured observations are a third category. Car and Driver reported a 40-minute 10–90% Tesla session versus 30 minutes on Electrify America for one tested 2025 IONIQ 5 XRT. MotorTrend reported separate 5–80% testing with a 126-kW Tesla peak versus 266-kW at a CCS site, and 32- versus 22-minute sessions.1516 Those independent 2025 test observations have different charge windows, equipment and conditions from Hyundai's 2026 10–80% maker tests: the figures are not interchangeable or a diagnosis of an owner's car.

For an actual charging stop, verify that the specific Supercharger is available to the selected vehicle, rather than assuming every Tesla connector or station is eligible.17 Compare the site's available voltage/power, the battery's current state of charge and temperature, and the source's model-year scope before comparing claimed peaks or charging times. Hyundai's 2020 E-GMP platform description explains motor/inverter voltage boosting at a platform level; it does not independently specify the 2026 model's measured peak at a particular station.2

Why 800V EV is not enough information

The architecture class and the charger voltage answer different questions. Hyundai's current 2026 IONIQ 5 specification, for example, lists exact battery voltages below 800V while still documenting the vehicle's higher-voltage fast-charging state.1 The E-GMP platform can accept 400V charging because Hyundai designed the motor and inverter to perform the voltage-boosting function.2

Porsche's current Taycan documentation describes another implementation. Its current technical press kit says a Combined Booster Charger (CBC) replaces the earlier DC/DC converter and first-generation HV booster while supporting up to 150 kW at 400V and up to 320 kW at 800V.3 Porsche's February 2024 U.S. launch release used the earlier phrase 150 kW DC/DC converter; that dated wording is useful historical context but is not used as the present component name.8

Lucid documents another implementation. The 926V Gravity uses its rear motor drive unit to boost 500V input and Lucid states up to 225 kW on 500V-class chargers versus up to 400 kW on 1000V equipment.4

The Mercedes-Benz examples are useful for the opposite reason: the current U.S. model pages publish separate 400V and 800V power limits, but the checked pages do not state the conversion mechanism.56 That field stays not established instead of being filled by inference.

Architecture voltage, battery voltage and charger voltage are different fields

Treat these separately:

  • Architecture class: the broad electrical design family commonly described as 400V, 800V or 900V+.
  • OEM-stated battery/system voltage: an exact figure when the manufacturer publishes one for the relevant battery or vehicle.
  • Charger output voltage: the voltage state the DC station can provide.
  • Vehicle acceptance power: the power the vehicle can actually take under that voltage state and current conditions.
  • Conversion method: the onboard hardware or pack strategy used to reconcile charger voltage with battery voltage, but only when the manufacturer actually establishes it.

A vehicle's peak charging number by itself does not prove its nominal architecture voltage or lower-voltage behavior.

What this means at a lower-voltage fast charger

Before a road trip, the useful questions are:

  1. Does this exact model/year support the charger's voltage class at all?
  2. If it does, has the manufacturer published a lower-voltage power limit or charging-time state?
  3. Is the limitation caused by a documented onboard conversion path, or is the mechanism simply not public in the checked source?
  4. Is the connector/network itself available to the vehicle?
  5. Is the battery warm enough and at an appropriate state of charge to approach the published charging capability?

Connector access is a separate problem from voltage compatibility. For Tesla Supercharger/NACS access by non-Tesla EV, use the non-Tesla Supercharger and NACS compatibility guide. For charging-time comparisons by vehicle and stated test state, use the EV DC fast-charging times guide. The battery-temperature state of a particular charging session cannot be diagnosed from a charger nameplate.

What is not established here

  • This is not a complete list of every 800V-class EV.
  • 800V-class is not treated as an exact pack-voltage claim unless the OEM publishes an exact figure.
  • A charger advertised at 150, 250, 350 or 400 kW does not guarantee the vehicle will receive that power.
  • Connector compatibility does not prove useful lower-voltage charging power.
  • A published 400V/500V power state does not prove a particular conversion mechanism unless the OEM says what the hardware is doing.
  • Hyundai's motor/inverter-boost mechanism is sourced to E-GMP technical documentation and paired with the exact current U.S. IONIQ 5 specification; this guide does not pretend the current trim table independently explains the mechanism.
  • Porsche's current durable row uses the current CBC terminology; the launch-era 150 kW DC/DC converter phrase is not presented as the current component name.
  • The Mercedes-Benz GLC/EQS rows intentionally preserve not established for conversion method.
  • For the U.S. CLA, a factory 400V converter is specifically described for qualifying MY2026 builds; 2027 model-specific 400V kW, exact conversion mechanism, a universal retrofit and every-VIN fitment are not established by the inspected sources.
  • Lucid Gravity's documented 926V/500V behavior is not generalized to Lucid Air without an exact current Air source.

Update policy

This living comparison changes when manufacturers revise model-year charging equipment, software, published 400V/500V limits, connector hardware or network access. Last full editorial source recheck: October 29, 2026. M20 independently examined the original Porsche, Lucid, Mercedes, Tesla and Hyundai owner documentation and both independently reported 2025 Hyundai charging tests, including the source-version and model-year distinctions. Hyundai's 2026 specification table is a limited exception: its live multi-megabyte comparison view could not be completely rendered, and exact source figures were rechecked against indexed Hyundai-issued sections rather than claimed as directly inspected complete table text.

Manufacturer documentation conflict still open: the exact 2027 Mercedes EQS 450+ model page lists a NACS DC inlet, while Mercedes' general 2027 charging page says the EQS uses CCS1. This reference does not decide which connector is installed on a given EQS VIN or provide physical-adapter instructions for it.611 The CLA manufacturer pages and Tesla charging policy were separately checked on October 29; the 2026 CLA factory-converter fitment and 2027 400V-specific kW ceiling still require equipment-specific manufacturer evidence.

Recheck the 2025/2026 Hyundai charging-source comparison by November 4, 2026, and the 2026/2027 CLA converter/voltage/adapter/Tesla-access guidance by November 5, 2026, or sooner when original equipment or network guidance changes. The whole guide's next forced review is November 4, 2026 because that is the earliest targeted refresh; this is not a guarantee that mutable specifications remain correct in the meantime.

Sources

Footnotes

  1. Hyundai Motor America — 2026 IONIQ 5 Features & Specs, U.S. manufacturer table originally inspected Sept. 21, 2026; current indexed Hyundai-hosted table/specification snippets independently cross-checked Oct. 29, 2026. https://aws-sweb.hyundaiusa.com/us/en/vehicles/ioniq-5/compare-specs Establishes 523V/697V battery values and published 400V NACS versus 800V CCS-adapter charger test conditions. The oversized live comparison table could not be completely rendered in this Oct. 29 review; indexed original-manufacturer text, not a full visual inspection, supports this row. ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9

  2. Hyundai Motor Group — E-GMP dedicated EV platform technical release, Dec. 2, 2020. https://www.hyundai.com/worldwide/en/newsroom/detail/0000000812 Establishes 400V/800V multi-charging and the motor/inverter voltage-boost mechanism at the E-GMP platform level. ↩ ↩2 ↩3 ↩4

  3. Porsche Newsroom — Taycan press kit, range and charging, current technical page observed Sept. 21, 2026. https://newsroom.porsche.com/en/press-kits/taycan/Die-Reichweite-und-das-Laden.html Establishes the current Combined Booster Charger description, its replacement of the earlier DC/DC converter and first-generation HV booster, up to 150 kW at 400V and up to 320 kW at 800V. ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  4. Lucid Group — Introducing the 2026 Lucid Gravity Grand Touring, April 15, 2025, observed Sept. 21, 2026. https://ir.lucidmotors.com/news-releases/news-release-details/introducing-2026-lucid-gravity-grand-touring-force-attraction Establishes the 926V pack, up-to-400-kW 1000V state, up-to-225-kW 500V-class state and rear-drive-unit boost mechanism. ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7

  5. Mercedes-Benz USA — GLC 400 4MATIC Electric SUV, current MY2027 U.S. model page, observed Sept. 21, 2026. https://www.mbusa.com/en/vehicles/model/glc/suv/glc400e4 Establishes 330 kW at 800V and 100 kW at 400V; the checked page does not establish the conversion mechanism. ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  6. Mercedes-Benz USA — 2027 EQS 450+ Sedan, current U.S. model page, rechecked Oct. 29, 2026. https://www.mbusa.com/en/vehicles/model/eqs/sedan/eqs450v Establishes 350 kW at 800V and 175 kW at 400V; does not establish the conversion mechanism or exact nominal pack voltage. Source discrepancy: this model page lists a NACS DC connector, whereas Mercedes' general 2027 charging guidance (R014) says MY2027 EQS models have CCS1. This guide does not resolve physical EQS plug fitment. ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8

  7. Porsche USA — Taycan model family, current MY2027 U.S. product page, observed Sept. 21, 2026. https://www.porsche.com/usa/models/taycan/taycan-models/taycan/ Establishes the current U.S. model-year family and continued 800V battery technology/up-to-320-kW charging state on applicable Taycan variants. ↩ ↩2

  8. Porsche Newsroom USA — The new 2025 Porsche Taycan models, Feb. 6, 2024. https://newsroom.porsche.com/en_US/2024/products/02062024_The_new_2025-_Porsche_Taycan_models.html Historical launch source: establishes the MY2025 launch-era wording 150 kW DC/DC converter plus up-to-320-kW 800V charging. The current R004 technical source controls the present component terminology. ↩ ↩2

  9. Mercedes-Benz USA — 2026 CLA Sedan future vehicles page, U.S. factory-converter qualification, inspected Oct. 29, 2026; page itself undated. https://www.mbusa.com/en/future-vehicles/2026-mercedes-benz-cla-sedan States 800V DC system, factory-equipped converter for 400V DC starting Spring 2026, and no 400V DC for vehicles without it. Does not determine any individual VIN or retrofit. ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10

  10. Tesla — Supercharging Other EVs, current NACS manufacturer and station-eligibility guidance, inspected Oct. 29, 2026; undated mutable page. https://www.tesla.com/support/charging/supercharging-other-evs Lists Mercedes-Benz enabled at the manufacturer level but excludes Tesla-only sites, distinguishes All EVs/Magic Dock from NACS-enabled stations and requires exact EV/site lookup. No universal Mercedes CLA Supercharger speed, per-VIN access or Tesla Plug & Charge guarantee. ↩ ↩2 ↩3 ↩4

  11. Mercedes-Benz USA — Charging Your Mercedes-Benz EV, current MY2027 U.S. charging guidance, inspected Oct. 29, 2026; page undated. https://www.mbusa.com/en/charge States 2027 CLA and GLC support both 400V and 800V DC; describes native NACS DC and included CCS1-compatible DC adapter for applicable MY2027 vehicles. Its statement that MY2027 EQS uses CCS1 conflicts with the exact EQS 450+ model page (R007), which lists NACS. Does not give a CLA 400V maximum kW. ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11

  12. Mercedes-Benz USA — 2027 CLA 250+ Electric Sedan specifications, inspected Oct. 29, 2026. https://www.mbusa.com/en/vehicles/model/cla/sedan/cla250e Lists J1772 AC 9.6 kW, NACS DC 320 kW general maximum, 22-minute stated DC 10–80%; does not give a separate 400V DC maximum. ↩ ↩2 ↩3 ↩4 ↩5

  13. Mercedes-Benz USA — 2027 CLA 350 4MATIC Electric Sedan specifications, inspected Oct. 29, 2026. https://www.mbusa.com/en/vehicles/model/cla/sedan/cla350e4 Lists J1772 AC 9.6 kW, NACS DC 320 kW general maximum, 22-minute stated DC 10–80%; no separate 400V DC maximum. ↩ ↩2 ↩3 ↩4 ↩5

  14. Hyundai Motor America — 2025 IONIQ 5 Tesla Supercharger charging instructions, current model-year-specific owner FAQ, inspected Oct. 28, 2026; page not independently dated. https://owners.hyundaiusa.com/us/en/resources/general-information/hyundai-charging-information-2025-ioniq5 Names up to 135 kW at Tesla Superchargers for the 2025 vehicle, with ideal-condition, temperature, SOC and site qualifications; does not define the MY2026 maximum. ↩ ↩2 ↩3

  15. Car and Driver — 2025 Hyundai Ioniq 5 NACS Charging Test, independent original test by Dave VanderWerp, April 11, 2025, inspected Oct. 28, 2026. https://www.caranddriver.com/news/a64410159/2025-hyundai-ioniq-5-nacs-port-charging-test/ One 2025 IONIQ 5 XRT 10–90% comparison (Tesla 40 minutes, Electrify America 30 minutes); not manufacturer specification or typical-condition guarantee. ↩

  16. MotorTrend — 2025 Hyundai Ioniq 5 NACS Charging Test, independent original test, June 4, 2025, inspected Oct. 28, 2026. https://www.motortrend.com/reviews/2025-hyundai-ioniq-5-nacs-range-charging-test Observed 126-kW Tesla versus 266-kW alternative peak and 5–80% times of 32 vs. 22 minutes; different conditions/windows, not a MY2026 rating. ↩

  17. Tesla — Supercharging Other EVs, current U.S. official support, inspected Oct. 28, 2026; undated page. https://www.tesla.com/support/charging/supercharging-other-evs Distinguishes supported station/vehicle access and using the Tesla app to find compatible stations; does not specify IONIQ 5 2026 vehicle power limits. ↩

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