In the current push to promote electromobility the crucial step of ensuring global standardization has yet to be sufficiently resolved. Discussion of global standardization is currently focused on electric vehicle charging standards. An international charging system standard is required to be able to guarantee that regardless of whether a vehicle is manufactured in Japan or China it will be fully compatible with the charging infrastructure of the United States or Germany. A charging standard defines both the technical charging methods, including voltage and the speed of the charging process, as well as the physical connector used to plug the vehicle into a station.

At present, there exist two major charging standards which are employed by electric vehicle manufacturers, the J1772 standard and the CHAdeMO standard, these standards can be roughly divided geographically with the J1772 standard being employed by North American and European auto manufacturers and the CHAdeMO standard being used by those in Japan. The J1772 standard was developed by a task force assembled by the Society of Automotive Engineers (SAE) an organization of scientists and vehicle engineers. The design specifications of the J1772 standard were developed by a committee composed of 150 car manufacturers, electrical equipment makers and utilities.  The Japanese CHAdeMO standard was developed by a consortium consisting of representatives from Nissan, Mitsubishi, Subaru and Tokyo Electric Power.

While a majority of North American and European auto manufacturers have committed to using the J1772 standard in their products, both now and in the future, the CHAdeMO standard remains the more prevalent charging standard across the world. The prevalence of the CHAdeMO standard is due in large part to its support of DC fast-charging, a standard which enables vehicles to be charged at much faster speeds utilizing direct currents of up to 500 V.  While the J1772 does not currently provide for the possibility of DC fast-charging, the SAE are actively developing a DC charging alternative to compete with the Japanese standard. This standard, however, will be placed at a considerable disadvantage when it is introduced in 2013 as the number of CHAdeMO stations in the U.S. alone is expected to reach the thousands by then. The considerable lead taken by the CHAdeMO standard may very well outweigh the rumored technological superiority of the SAE supported fast-charging standard, as auto manufacturers are keen to take advantage of the existing infrastructure available for the Japanese standard.

Both the CHAdeMO standard and the SAE’s upcoming fast-charging standard have been claimed to be universal.  However, the true universality of any individual charging standard depends upon the forming of a consensus among the world’s auto manufacturers, as neither standard is likely to eliminate the other on purely technological grounds. Thus, industry experts predict a future in which the two standards co-exist, with the burden falling to electric vehicle owners to determine which standard is more readily available in their area. This compromised future is hardly conducive to a wide scale, public adoption of electrified transport and therefore, the need to develop a universal charging standard remains a key priority in the future development of electric vehicles.

The development of a universal charging standard is among the chief goals of the Eco Urban Living initiative.

Read More:
A NY Times article on the competing standards 
An article in Scientific American regarding fast charging standards
An article on Smart Planet regarding the development of fast charging methods