Better Place demonstrates a battery swap.
SPARKS are flying over the future of battery technology as Mercedes-Benz publicly spars with international green energy group Better Place.
Mercedes' future mobility boss Professor Herbert Kohler has slammed the group saying its aim to provide battery swapping sites for electric vehicles won't work and is potentially dangerous.
As Mercedes starts revealing its future electric vehicle program, Kohler has squared up against Better Place saying he has "no confidence" in its model or its projection of one-billion electric cars on the road by 2015.
Better Place aims to become a global provider of EV infrastructure, including charging stations and battery swapping sites.
The company has already set up a national network operations centre in Victoria to control the software that will run the recharge network in Australia and has unveiled its first charging station in Canberra.
But it is the battery swap plans that concern Kohler and - he says - many other carmakers.
Better Place Australia CEO Evan Thornley hit back, saying "rumours of the death of battery switching from competing commercial interests like Mr Kohler may be greatly exaggerated".
"In Tokyo last year, Better Place ran a taxi trial with battery switchable vehicles that ran through all weather conditions seamlessly, switching the batteries 3470 times during the five-month trial," he says.
"There continues to be a groundswell of support for Better Place and battery switching technology as a facilitator to the mass adoption of electric vehicles globally."
Professor Kohler says Better Place founder Shai Agassi's position has repeatedly changed and was now looking for a common infrastructure across competing car brands.
"It is very seldom car manufacturers share the same opinion, but 95 per cent of us are in the same position ... no one is interested in having `one size fits all' on the battery side," Professor Kohler says.
"It is not feasible."
He says the cost of the battery - up to 50 per cent of the cost of small cars - means carmakers won't share batteries because they don't know how the replacement product has been made or how it has been treated during previous swaps.
"What is the lifetime of that battery and so on," he says.
"There is also one big problem in the economic case, because the battery is rather expensive, but in the next five to 10 years we do see a reduction in cost because of economy of scale. What Agassi is going to invest in now (replacement batteries) is going to change. A battery that cost $1500 a kilowatt hour in five to 10 years will be $750 a kWh. And that is not reflected in their business case. With those kinds of guys we don't want to make business."
Mr Thornley says Professor Kohler is incorrect about Better Place's cost assumptions and any expectations around battery standardisation.
"We expect and welcome falling battery costs - they will drive even lower costs for electric driving," Mr Thornley says.
"We have built our business model around accommodating a range of different batteries for different-sized and configured vehicles."
Professor Kohler also struck out over the issue of safety in battery swaps.
"I don't want to have someone dealing with a battery and to try do it as quickly as possible and oh, by the way he forgot the right connectors and the right position," he says.
"Who is responsible then when a mother and two children will get that electric shock. Who will be the responsible guy? Never, ever Better Place, it will always be Mercedes, because we are a big company and they can get more money out of us and so on."
Mr Thornley says safety is a "principal concern for any reputable company in the automotive or electricity business".
"Better Place is no exception and nor is global auto company, Renault, or electricity giants, General Electric (GE), who have partnered with us. The data from the field also demonstrates strong safety performance.
"Better Place raised one of the largest clean tech finance rounds in history last year led by HSBC, one of the world's leading banks who, along with Morgan Stanley and Lazard, scrutinised our business model thoroughly.
"The Chinese government, as custodians of the world's largest car market, have indicated strong support for battery switching technology and the world's largest utility, State Grid Corporation of China, has conducted a battery switch pilot in Hangzhou."