"""The vehicle is powered by four Z37 ZEBRA sodium nickel chloride hot batteries manufactured in Switzerland. The batteries are rated as 20kWh each for a nominal total of 80 kWh, which should have been more than enough to complete a regular 10 hour shift. But as in all new technologies, there is still much to be learned and improved

Martin explained that during the just over a month of in the field testing during 2007, the pack actually produced only 65 kWh of energy, and one of the individual 20kWh modules failed, requiring replacement. But this wasn't the first time the ZEBRAs failed. Another 20kWh unit also failed during off-road tests at Transport Canada. Not a promising start; and these are the same batteries being used in both the Smith and Modec heavy trucks being operated in the UK.

According to Martin, the battery manufacturer's explanation for the high rate of failure isn't the chemistry, but manufacturing related, something in the process was "out of spec." Needless to say, Unicell is on the hunt for another battery solution and they’ve turned to their Toronto neighbor, Electrovaya and its Lithium Superpolymer battery"""

Would need to talk to EFL to see where this all stands as of today.