# A Review on Standardizing Electric Vehicles Community Charging Service Operator Infrastructure
## 4 Charging Type
### Conductive Charging
#### 4.1.3 Charging Standards  
This section discusses the different charging standards based on the conductive charging. Figures 4-6 shows the existence of charging standards based on the different countries, manufacturers, and types of EV. These can be mentioned as follows:  
* SAEJ1772 The SAEJ1772 charging standard is used for EV conductive AC charging, especially in North America. However, the SAEJ1772 charging standard also supports DC charging to achieve high-level energy transfer for fast EV charging. The International Society of Automotive Engineers mainly initiates it. The essential features of the standard can be characterized with the help of various parameters such as power supply level, different charging levels, charging time, charging cost, adaptability in different countries, and the network communication protocol between the charger and EV [66]. The charging time and voltage involved in the standard for conductive charging vary with the charging levels for 2W, 3W, and 4W EVs. The charging time for SAEJ1772 lies in the range of 4-7 h for charging Level 1 with the charging power level of 120 V. With charging Level 2 and Level 3, EVs can be charged with a charging time of 2-3 h and 0.5 h, corresponding to the charging power level of 240 V and 450 V [67]. Previously, EVs were charged wirelessly with the help of the inductive charging method. However, the government agency of California, i.e., the California Air Resources Board proposed the idea of the SAEJ1772 standard in the year 2001. Since 2001, most EVs have started adopting the SAEJ1772 standard in countries such as the USA, Germany, Japan, and Finland, and are manufactured by various companies such as Yazaski, Chevrolet Volt, Nissan Leaf, Teison, etc. [68]. * CHAdeMO The CHAdeMO charging standard is mainly used for EV conductive fast DC charging developed with considerations for compatibility with the industry. Japanese manufacturers first developed the standard to support three level charging [69]. Some countries, including Japan and Germany, use the CHAdeMO charging standard for EVs with a charging time of 0.5-1 h based on charging Level 3 along with the charging power level of 480 V for 4W vehicles. The EV requirement of charging determines the adaptability of the CHAdeMO charging standard. If EVs want to opt for fast  
Figure 4: Taxonomy of charging standards based on the countries. charging, they can use the CHAdeMO charging standard. However, they should also contain the same charging connector to achieve efficient and fast charging [70,71]. CHAdeMO has been utilized widely in several countries such as Japan, Norway, and Germany, in which many manufacturers such as Nissan Leaf, Yazaki, Fuzikura, etc., have started expanding their business by manufacturing the charging standard for fast DC EV charging. * CCS Combo 1/Combo 2 Many countries such as Japan and others in Europe are expanding their infrastructures to introduce fast charging connectors for efficient EV charging. Unlike CHAdeMO, the CCS charging standard is being adopted by countries worldwide. CCS combo 1, based on the SAEJ1772 conductive charging standard, was first coordinated and employed by a company named CharIN to facilitate EVs with fast DC charging. After this, CCS combo 1 (based on the AC type 1) was upgraded to the CCS combo 2 charging standard, which is based on AC type 2 charging. CCS combo 1 and CCS combo 2 charging standards can charge 4W EVs with a variable charging power, which lies between 600 V and 1000 V [72]. Moreover, EVs do not need to acquire extra space for this type of connector due to the usage of AC type 1 and type 2 chargers with DC connector pins for low voltage fast DC charging. The sustainable feature of the CCS charging standard has been adopted by Tesla since 2018. It means they can make use of the CCS combo 2 charging connector with superchargers for EV charging, increasing its usability [73,74]. Many manufacturers incorporate the CCS combo charger along with the Tesla, which includes Honda, VW eGolf, Mini Electric, Mercedes etc.