Test results of computer-generated simulated driving profiles applied to near-term batteries

Simulated driving profiles applied in the laboratory have considerable merit in the comparison of batteries being tested and evaluated for electric vehicle application. This paper describes a simplified version of a driving profile test and presents the results of tests using the simplified profile and a more sophisticated simulated driving power profile. These tests were applied to improved lead-acid, nickel/iron and nickel/zinc batteries developed under the Near-Term Battery Development Program that is administered by Argonne National Laboratory (ANL) for the Department of Energy (DOE). In all tests, the battery power profile used is from the SAE J227AD urban driving schedule as would be negotiated by the newly developed ETV-1 electric vehicle. As a means of comparing electric-vehicle batteries in the laboratory, ranges achieved with and without regenerative braking are reported. The following conclusions were reached from these tests: notable increases in range were indicated in every battery when regenerative braking was used; charge acceptance by the batteries seemed particularly good during the regenerative braking phase; and little or no additional thermal burden was imposed on the battery by the use of regenerative braking (in fact, in some systems, cooling was slightly enhanced by entropy effects associated with battery charging during regenerative braking). This paper is largely an update of a paper presented at the EV Expo '80 in St. Louis, Missouri on May 20-22, 1980. A companion paper described the general status of the Near-Term Battery Program. The following is a brief description of the Near-Term Battery Program presented as a prelude to the main theme of this paper.