Continuing just-auto’s series of interviews with major automotive battery producers, Matthew Beecham talked with Masato Furumi, General Manager, Business Promotion Department, Automotive Battery Business Promotion Division, International Business Unit, GS Yuasa International Ltd.

In what ways do your lead-acid batteries for stop-start vehicles differ from conventional batteries?

They have higher output power, higher input power (charge acceptance), and higher endurance against frequent high-rate discharge. This is achieved by producing cells with an increased number of thinner plates with the appropriate type and amount of carbon additive in the negative plates and higher density positive active material and higher endurance positive grids. These measures protect the batteries from stratification, sulphation and prevent grid corrosion due to lower electric potential.

Some people believe that the emerging EV and PHEV markets could flatten out due to unproven technology.  They reckon that the market will be initially bolstered by heavy subsidies to automakers, battery makers and consumers but that sustained growth will depend on yet-to-be-proven battery technology as well as on supporting government policies.  Would you agree?

We think that the development of Li-ion battery technology for EVs is still at a relatively early stage and that will not in itself hinder the EV and PHEV market growth. The mobile phone and PC markets have developed in a similar fashion.

I guess that the stubbornly high cost of battery packs – which can account for about half the cost of an electric vehicle – is a big hurdle.  Presumably, the costs need to be reduced to below $400 a kilowatt hour to make it commercially attractive? 

Battery price has sharply reduced and is already much lower than half of EV price. Although the Japanese yen is currently strong, module price of $400 a kilowatt hour is an achievable target.

If the cost of battery packs can be significantly reduced, where will the cost reduction come from? i.e. efficient factory management, cutting waste and other management-related expenses or from fundamental improvements in battery technology?

The automotive large Li-ion battery business is relatively new and still developing. Battery price can be reduced drastically by mass production scale expansion. Consequently, the production scale for parts suppliers will expand and parts costs will reduce. The price for small Li-ion batteries is now under $400 a kilowatt-hour because the market scale is large enough. Furthermore, as batteries with higher energy density are developed, price per kilowatt-hour will fall.