Batteries in solar home systems can cause problems and costs for the users and/or operators of the systems. In Zambia the Lundazi Energy Service Company (LESCO) operates 150 solar home systems on a fee for service basis. The aim of the study was to investigate how the capacity of lead-acid flat plate batteries had changed after one year of operation under real conditions. The results indicate that the batteries capacity has been significantly reduced in comparison to new unused batteries of the same type. Changes in battery management and maintenance, along with. additional education of customers on correct use of SHS is advised in order to improve the life span of batteries in practical use. (c) 2004 Elsevier Ltd. All rights reserved.