Electric car

Press, 25 August 1979, Page 14

Electric car

Sir, — A. Delhanty (August 14) states; “No costly maintenance.” I would like to see an expert opinion on the battery problem, because the cost of batteries of the necessary capacity will be very high while conventional batteries, i.e. leadacid have a relatively short life. Replacing these would make nonsense of the cheap maintenance theory. Nickel iron batteries have been used where long life was a requirement but they were much more expensive. Can any one shed some light on the present situation? — Yours, etc., M. A. ENSOR, Diamond Harbour. August 14, 1979. [Mr R. T. C. Harman, senior lecturer in mechanical engineering, University of Canterbury, replies: “The first point to consider is the expected battery life. Battery company policy in the United Kingdom is not to release batteries for traction purposes until they can be guaranteed for 1000 deep cycles, or four years minimum life, and policy here is likely to be similar. If the batteries are not heavily discharged each day, they will last longer, up to perhaps seven or eight years with careful charging and maintenance. Apart from battery replacement, the operating costs of the electric car promise to be very low. We favour the concept of paying for the replacement battery on a monthly basis as the vehicle is used from new, under a battery performance contract with your local battery company. Then, as with a rented TV set which fails, replacement is arranged as required. The terms of such a contract might include a reduced payment rate after three years, to favour the user who obtains six years from his battery. The cost of battery payments and operation are likely to remain less than petrol car costs, particularly if the vehicle is used commercially. The much longer life of nickel iron batteries would make them attractive to careless users, or for cars running low annual distances. However, they would be more expensive, they store less energy for a given weight, and they are not readily available. Future technological improvements and the development of new battery systems can only make the electric vehicle more attractive, but our

work on the University of Canterbury electric vehicle project suggests that leadacid powered vehicles are already viable. The use of 75,000 electric milk floats in Britain says the same.”]