A method for maintenance, repair and/or optimization of a battery. The battery has, as components, individual cells connected to one another in series and/or in parallel, having electrical terminal contacts which are connected to one another positively and/or firmly, directly or by cell connectors, forming an overlapping region, and/or a battery monitoring unit having a number of connection elements which are positively and/or firmly connected to the electrical terminal contacts and/or to the cell connectors, forming a further overlapping region. To exchange a component, the positive and/or firm connection of the component to be exchanged to at least one component not be exchanged is separated directly next to the overlapping region and a replacement component is connected positively and/or firmly to the overlapping regions of the at least one component not be exchanged by the electrical terminal contacts thereof or the connection elements thereof, forming a respectively new overlapping region.