[{"data":1,"prerenderedAt":173},["ShallowReactive",2],{"guide-ev-charging-standards-gbt-ccs-nacs-en-US":3},{"guide":4,"related":154},{"title":5,"seoTitle":6,"description":7,"summary":8,"sections":9,"faq":116,"date":126,"service":127,"order":128,"sources":129,"slug":152,"locale":153},"Comparing the GB\u002FT, CCS, NACS, CHAdeMO and ChaoJi charging standards on openness, security and reliability","GB\u002FT vs CCS vs NACS Charging Standards","How China's GB\u002FT compares with CCS, NACS (SAE J3400), CHAdeMO and ChaoJi, and a fact check of claims about Tesla, GB\u002FT and V2L in China.","GB\u002FT is more open than CCS in one specific sense: its specifications are published by the Chinese state and are generally cheaper to obtain, while CCS and NACS documents are sold by ISO and SAE. The certificates in CCS are not what makes it closed, because ISO 15118-2 requires TLS encryption only for Plug and Charge and most sessions run without it. Neither standard is secure by default. In China, the GB\u002FT charging standards are formally recommended rather than mandatory, and no Chinese standard requires vehicles to offer V2L.",[10,55,60,68,73,82,111],{"heading":11,"paragraphs":12,"table":14,"after":53},"Three different meanings of open",[13],"Discussions of charging standards often treat open as one quality. It is more useful to separate three questions: whether anyone can read the specification and at what cost, who governs the standard and certifies equipment, and how the car and charger communicate. Security and reliability are separate questions again.",{"caption":15,"head":16,"rows":22},"How the five standards are published and governed, as of October 2026",[17,18,19,20,21],"Standard","Main markets","Access to the specification","Governance and certification","Charging communication",[23,29,35,41,47],[24,25,26,27,28],"GB\u002FT (GB\u002FT 20234 connectors, GB\u002FT 18487.1 system, GB\u002FT 27930 communication)","Mainland China","Published by the state; SAMR runs a public platform with free online reading for many national standards; English translations are sold by third parties","National standards bodies; the GB\u002FT charging parts are recommended standards; a mandatory safety standard, GB 44263-2024, has applied since August 1, 2025","CAN bus on dedicated connector pins",[30,31,32,33,34],"CCS1 and CCS2","CCS1 in North America, now giving way to J3400; CCS2 in Europe","Sold by IEC and ISO; ISO 15118-20 is priced at CHF 227 per part","Industry-led; CharIN conformance testing; Plug and Charge requires PKI certificates","Power-line communication over the control pilot, using DIN SPEC 70121 or ISO 15118",[36,37,38,39,40],"NACS (SAE J3400)","North America","Tesla published the design in November 2022; SAE documents are sold","SAE International: Technical Information Report in December 2023, Recommended Practice in 2024, J3400\u002F2 for hardware","Uses the CCS DC communication protocols; the change is the connector",[42,43,44,45,46],"CHAdeMO","Japan; earlier Nissan Leaf models in the US","Published through IEC; the full specification and certification rights go to Regular members at 4,000 euros a year","CHAdeMO Association","CAN bus",[48,49,50,51,52],"ChaoJi","China and Japan, in development","In China, through the high-power DC parts of the GB\u002FT series","Joint China-Japan development","Designed for very high power; few production vehicles so far",[54],"On access and cost, GB\u002FT is the more open standard, and that difference is real. On governance, GB\u002FT is state-run while CCS and NACS are industry-run, which is a different model rather than a more or less open one.",{"heading":56,"paragraphs":57},"Certificates are not what makes CCS closed",[58,59],"A widely shared view holds that CCS is locked down by encryption certificates while GB\u002FT uses simple CAN messages anyone can implement. The first half of that view is inaccurate. Under ISO 15118-2, TLS encryption is required only for Plug and Charge, the feature that lets a car start and pay for a session automatically, and only the charger authenticates itself. Most CCS sessions run without TLS. DIN SPEC 70121, which many US DC fast chargers still use, is widely reported to include no TLS at all.","ISO 15118-20, the newer version that supports bidirectional power transfer, makes mutual TLS 1.3 mandatory for all sessions, according to CharIN and vendor implementation guides. Even so, anyone can build a CCS charger without a PKI certificate. What a manufacturer cannot offer without certificates is Plug and Charge billing. The paywall on the documents and the cost of conformance testing are the real barriers, not the cryptography.",{"heading":61,"list":62,"after":66},"Neither standard is secure by default",[63,64,65],"GB\u002FT 27930-2015 messages are broadcast in plain text with no source or destination addresses. Li and colleagues (Journal of Computer and Communications, 2019) captured 27,655 messages from a real charging session and demonstrated replay attacks. Adding RSA signatures alone did not stop replay; adding nonces did.","A 2025 preprint by Shi and colleagues describes weak authentication in the GB\u002FT 20234.2 connection-confirmation circuit, which relies on resistor values.","CCS: the Brokenwire attack (Köhler and colleagues, University of Oxford, NDSS 2022) used a wireless signal to abort charging sessions from up to 47 meters with less than 1 watt of power. It exploits the power-line communication shared by DIN SPEC 70121 and ISO 15118 and was tested against multiple production vehicles and chargers.",[67],"Our position is that certificates matter most for vehicle-to-grid at scale. When thousands of cars export power on command, the commands and the billing must be authenticated, or the grid itself is exposed. That is the purpose of ISO 15118-20 and of the US EV public key infrastructure framework that the SAE EVPKI Consortium and the Joint Office of Energy and Transportation announced in December 2024. China has also revised its communication standard, and GB\u002FT 27930-2023 replaced the 2015 edition in April 2024.",{"heading":69,"paragraphs":70},"What the reliability data shows",[71,72],"In the US, J.D. Power's 2025 public charging study found that 14 percent of EV owners had a visit in which they could not charge, down from 19 percent in 2024, and its 2026 study was reported to show a record low of 12 percent for failed DC fast charging visits. We found no national failure-rate statistic for China. China does have an interoperability test standard, GB\u002FT 34657.1, revised in 2025, and Chinese drivers are familiar with handshake failures between cars and chargers.","Without comparable data, we do not claim that GB\u002FT is more reliable. As an engineering judgment, CAN on dedicated pins is electrically simple and robust, while power-line communication on the pilot wire is more sensitive to electrical noise and implementation errors.",{"heading":74,"list":75},"Strengths and weaknesses of each standard",[76,77,78,79,80,81],"GB\u002FT: low-cost access to the specification, very large installed base and simple CAN communication. Drawbacks are separate AC and DC inlets, limits in the 2015 generation, weak built-in security and use limited to mainland China.","CCS1: mature, with a roadmap to bidirectional power through ISO 15118-20. Drawbacks are a bulky connector, a mixed US reliability record and paid specifications. In North America it is being replaced at the vehicle inlet by J3400.","CCS2: Europe's required standard, combining three-phase AC and DC in one inlet. It is not used in the US.","NACS (SAE J3400): a compact single inlet for AC and DC, rated to 1,000 volts under J3400\u002F2, with access to Tesla Superchargers. Adapters are common during the transition, and because the DC communication is the same as CCS, the CCS security issues carry over.","CHAdeMO: the first standard with bidirectional DC, used for Leaf V2H since about 2012. It has effectively ended in the US; the 2026 Leaf uses NACS for DC charging.","ChaoJi: designed for very high power with backward compatibility. Few or no production cars use it yet.",{"heading":83,"paragraphs":84,"table":86,"after":109},"What Chinese standards actually required of Tesla",[85],"A popular claim holds that China forced Tesla to adopt GB\u002FT and to enable vehicle-to-load (V2L). We checked each part against China's national standards database.",{"caption":87,"head":88,"rows":92},"Fact check based on the SAMR national standards database, October 2026",[89,90,91],"Claim","Verdict","Basis",[93,97,101,105],[94,95,96],"The GB\u002FT charging standards are mandatory","Inaccurate","GB\u002FT 20234.1-2023 and GB\u002FT 20234.3-2023 (effective September 7, 2023), GB\u002FT 18487.1-2023 and GB\u002FT 27930-2023 (effective April 1, 2024) are listed as recommended standards. The prefix GB without T marks a mandatory standard.",[98,99,100],"China forced Tesla to adopt GB\u002FT","Partly true","Tesla has fitted GB\u002FT ports to China-market cars since 2017. Market access, subsidies and compatibility with the public network made GB\u002FT a practical requirement rather than a single mandatory rule. Since August 1, 2025, the mandatory GB 44263-2024 sets safety requirements for charging systems, including charge-discharge systems.",[102,103,104],"A Chinese standard forced Tesla to enable V2L","False","GB\u002FT 18487.4-2025 (recommended, effective November 1, 2025) sets requirements for vehicles that offer external discharge; it does not require every vehicle to offer it. Tesla added V2L to the Model Y L in China through software update 2025.32.300, announced October 31, 2025, at up to about 2.2 kW with an official adapter priced at 599 yuan at launch. Tesla also offers V2L in the US on the Cybertruck.",[106,107,108],"China has a national V2G policy","Confirmed","The NDRC and three other agencies issued policy document 1721 (2023), published January 4, 2024, calling for at least five pilot cities and 50 bidirectional projects by the end of 2025. The first pilot list, issued April 2, 2025, named 9 cities and 30 projects. These are pilots and price signals, not vehicle mandates.",[110],"V2L in China spread through competition: most Chinese brands offer it as a feature for camping and outages, and Tesla followed the market.",{"heading":112,"paragraphs":113},"What this means for a home charger in New York",[114,115],"In North America the connector question is settled in favor of J3400. The next changes are in communication and security: ISO 15118-20, certificate infrastructure and the UL 1741 SC certification for bidirectional AC charging. A charger bought today should accept firmware updates, and the wiring should be planned so that the charger can be replaced without rewiring.","We install home and commercial chargers across NYC and Long Island, with electrical work performed by licensed partner electricians, and we size the circuit and conduit so that the next charger can be swapped in. Our guide on preparing a renovation for bidirectional charging covers the wiring in more detail.",[117,120,123],{"q":118,"a":119},"Does Tesla use GB\u002FT charging ports in China?","Yes. Tesla has fitted GB\u002FT ports to China-market vehicles since 2017. The reason was compatibility with China's public charging network and market access, not a single mandatory standard; the GB\u002FT charging standards themselves are recommended standards.",{"q":121,"a":122},"Is NACS a different protocol from CCS?","For DC fast charging, NACS (SAE J3400) uses the same communication protocols as CCS. The main change is a smaller connector that handles both AC and DC, which is why adapters between the two work.",{"q":124,"a":125},"Are all Chinese national standards mandatory?","No. Standards numbered GB are mandatory, while those numbered GB\u002FT are recommended. Most charging standards, including GB\u002FT 20234, GB\u002FT 18487.1 and GB\u002FT 27930, are recommended. GB 44263-2024, a charging system safety standard, is mandatory.","2026-10-25","ev-charging",51,[130,134,137,140,144,148],{"title":131,"url":132,"publisher":133},"GB\u002FT 27930-2023 非车载传导式充电机与电动汽车之间的数字通信协议 - 全国标准信息公共服务平台","https:\u002F\u002Fstd.samr.gov.cn\u002Fgb\u002Fsearch\u002FgbDetailed?id=053404E3EF398F91E06397BE0A0A9209","国家市场监督管理总局",{"title":135,"url":136,"publisher":133},"GB 44263-2024 电动汽车传导充电系统安全要求 - 全国标准信息公共服务平台","https:\u002F\u002Fstd.samr.gov.cn\u002Fgb\u002Fsearch\u002FgbDetailed?id=1E0A96CB22374BB4E06397BE0A0AA9ED",{"title":138,"url":139,"publisher":133},"GB\u002FT 18487.4-2025 电动汽车传导充放电系统 第4部分：车辆对外放电要求 - 全国标准信息公共服务平台","https:\u002F\u002Fstd.samr.gov.cn\u002Fgb\u002Fsearch\u002FgbDetailed?id=33D40F11613A5D92E06397BE0A0A5B93",{"title":141,"url":142,"publisher":143},"SAE completes TIR for J3400 standard","https:\u002F\u002Fwww.sae.org\u002Fsite\u002Fnews\u002F2023\u002F12\u002Fsae-j3400-tir-released","SAE International",{"title":145,"url":146,"publisher":147},"Brokenwire: Wireless Disruption of CCS Electric Vehicle Charging - NDSS Symposium","https:\u002F\u002Fndss-symposium.org\u002Fndss-paper\u002Fbrokenwire-wireless-disruption-of-ccs-electric-vehicle-charging","NDSS Symposium",{"title":149,"url":150,"publisher":151},"特斯拉正式支持“外放电”：Model Y L 推送 2025.32.300 软件更新，新增低电量模式等功能 - IT之家","https:\u002F\u002Fwww.ithome.com\u002F0\u002F893\u002F932.htm","IT之家","ev-charging-standards-gbt-ccs-nacs","en-US",[155,161,165,169],{"slug":156,"title":157,"description":158,"service":159,"date":160},"nyc-renovation-permits","NYC permits for renovation, electrical and plumbing work","Which renovation, electrical and plumbing jobs need a NYC Department of Buildings permit, who files it, and what changes on Long Island.","electrical","2026-10-24",{"slug":162,"title":163,"description":164,"service":159,"date":160},"electrical-panel-upgrade","Electrical panel and service upgrades for NYC and Long Island homes","When an older NYC or Long Island home needs a new panel or a bigger electrical service, what the work involves, and how long it takes.",{"slug":166,"title":167,"description":168,"service":127,"date":126},"ev-charging-without-service-upgrade","EV charging without an expensive service upgrade","Load sharing, CT-clamp load management, dryer-outlet sharing and right-sized chargers: ways to add EV charging in NYC and Long Island without upgrading your electrical service.",{"slug":170,"title":171,"description":172,"service":127,"date":160},"ev-charger-installation","Installing a home EV charger in NYC or Long Island","Level 1 vs Level 2 charging, panel capacity, permits, Tesla Powershare, and what to know for houses and buildings in NYC and Long Island.",1792924279790]