Eoin Treacy's view Charging stations for electric cars are becoming increasingly visible and the innovations introduced by Tesla Motors are helping to reduce range anxiety. As an increasing number of auto manufacturers invest in electric car focused R&D, the cost of these cars should also decline. The viability of electric cars and how well they penetrate the wider auto market will in no small part be dependent on improvements in battery technology, not least in achieving better power to weight ratios.

Tesla Motors is a high profile success story in the electric car market and is likely to benefit from heightened competition in the manufacture of electric power trains. The share has rallied from $40 to almost $200 since May and has at least paused over the last month.

Among US listed battery manufacturers, a number of high profile start-ups such as Ener1 and A123 have disappeared while more established companies such as Johnson Controls and EnerSys move from strength to strength. Johnson Controls has held a progression of higher reaction lows since October 2012 and is now testing its 2011 peak below $45. A break in the progression of higher reaction lows, currently near $40 would be required to begin to question medium-term demand dominance. EnerSys which manufacturers everything from lead batteries for cars to military grade submarine batteries has accelerated higher this month. The first clear downward dynamic is likely to signal a peak of at least near-term significance. (Also see Comment of the Day on August 10th 2012)

PolyPore International is a manufacturer of wide selection of membranes including those used in batteries. The share hit a medium-term peak in 2011 and has been building support mostly above $35 since 2012. It found support in the region of $40 this month and a sustained move below that level would be required to question medium-term scope for continued higher to lateral ranging.

South Korean listed Samsung SDI encountered resistance this week in the region of the 2011 peak; posting a large downside key reversal. At least some consolidation of powerful gains over the last six months now appears the most likely scenario. LG Chem also pulled back this week.

Hong Kong listed BYD has held a progression of higher reaction lows for the last year but has paused in the region of HK$40 and some consolidation looks more likely than not.

Japan's Panasonic continues to pause below ¥1000 but a sustained move below the 200-day MA, currently near ¥800, would be required to question medium-term scope for continued higher to lateral ranging.

This article from autobloggreen may be of interest.

It is also worth highlighting that while electric vehicles garner a great deal of media attention that they are not the only alternative fuel vehicles. The California EPA's Air Resources Board contains a list of fuel efficient cars which are permitted to use the state's carpool lanes with a single occupant. It can therefore be considered a reasonably complete list of “eco-friendly” vehicles.

Westport Innovations acquired BAF Technologies from Clean Energy Technologies in June. As well as a joint venture with Cummins for powertrain development and a CNG locomotive division, the company is now also the largest converter of Ford and Volvo cars to CNG power trains. The share has been impacted by spending on acquisitions and has returned to test the 2012 lows near $22.50. A clear upward dynamic will be required to reconfirm support in this area.