Journal of Power Sources 207 (2012) 30–36 Contents lists available at SciVerse ScienceDirect Journal of Power Sources jou rnal h omepa g e: www.elsevier.com/locate/jpowsour Dynamic charge acceptance of lead–acid batteries: Comparison of methods for conditioning and testing  Heide Budde-Meiwes a,∗ , Dominik Schulte a , Julia Kowal a , Dirk Uwe Sauer a , Ralf Hecke b , Eckhard Karden c a Electrochemical Energy Conversion and Storage Systems Group, Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, Jägerstraße 17-19, 52066 Aachen, Germany b Digatron Industrie-Elektronik GmbH, Aachen, Germany c Ford Research and Advanced Engineering Europe, Aachen, Germany a r t i c l e i n f o Article history: Received 25 October 2011 Received in revised form 15 December 2011 Accepted 20 December 2011 Available online 30 December 2011 Keywords: Lead–acid battery Charge acceptance Short-term history Micro-hybrid vehicle a b s t r a c t Dynamic charge acceptance (DCA) is a key requirement for batteries in micro-hybrid vehicles. In auto- motive applications, DCA reaches a stable level during several weeks or months in service. A conditioning method that accelerates stabilizing DCA is presented. Various test methods for evaluation of DCA are com- pared. This is necessary for comparing new technologies (e.g. negative electrodes with carbon additives) and cell concepts (e.g. bi-polar batteries). © 2011 Elsevier B.V. All rights reserved. 1. Introduction A micro-hybrid vehicle requires higher performance of its starter battery compared to conventional vehicles. Stop/start and regenerative braking are the hybridization features used for micro- hybrids, while avoiding the need for a high-volt (above 60 V) electric motor and traction battery. In its most widespread, and lowest cost, implementation, the topologies of a micro-hybrid vehi- cle’s power train and electric power supply system are the same as in conventional vehicles with internal combustion engine, i.e. a 14 V generator with modified control algorithms and one lead–acid battery (or sometimes two) perform the brake energy recupera- tion. Together with novel vehicle functions like electrically assisted brakes and steering systems, or cabin pre-heating during key-off, micro-hybridization confronts the starter battery with substan- tially increased energy throughput by micro-cycling with a typical amplitude (depth of discharge, DOD) around a few percent state of charge (SOC) or less. Fast recharge of the battery during these micro-cycles under a broad range of real world usage conditions,  Presented at 8th LABAT (International Conference on Lead–Acid Batteries), Albena, Bulgaria, 7–10 June 2011. ∗ Corresponding author. Tel.: +49 241 80 99579; fax: +49 241 80 92203. E-mail address: batteries@isea.rwth-aachen.de (H. Budde-Meiwes). like temperature and driving profiles, is a pre-requisite for consis- tently high availability of stop/start and other essential functions for the customer. It has been proposed to characterize the recharge ability of vehicle starter batteries as dynamic charge acceptance (DCA) [3]. Fuel savings due to regenerative braking critically depend on the DCA of the battery [10]. With an appropriate modification of the alternator control strategy, lead–acid batteries can provide brake energy recuperation functionality, as was shown by Karden et al. [2], Liebl et al. [6] and Schaeck [11]. However, the dynamic charge acceptance of lead–acid batteries in operation is not very consistent and hard to predict. Carmakers have introduced vary- ing test methods for DCA into their specifications for micro-hybrid starter batteries, and a harmonized DCA test method is being devel- oped by the European industry within battery standardization (prEN 50342-6). The aim of the present paper is to propose a quick conditioning and testing method for DCA to produce performance measurements that are representative of real world conditions. DCA is investigated during regenerative braking events with a duration in the time range from 3 to 20 s. As a definition of DCA usually the average charge current or the charge current after a certain time is analysed (e.g. after 10 s). There are two different DCA conditions to be considered. The first DCA is obtained while the car is regularly driven without longer parking phases (maximum one weekend or so), the second DCA is defined as DCA obtained after a long parking period (e.g. airport) after which significant recovery of SOC is demanded. 0378-7753/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.jpowsour.2011.12.045