This study presents a decentralised off-line strategy for optimal hybridisation and management of photovoltaic (PV)/batteries hybrid systems in residential distribution grids. The aim is to study the voltage plan of the network without/with this process for different penetration rates of PVs and also comparing with the initial grid without PV. The tool has been tested by using a real Swiss distribution network and real data of houses electricity consumption. In addition, a voltage assessment methodology has been proposed. Lot of study cases has been performed and the results show that the voltage plan of the grid is greatly improved, thanks to the tool proposed. For quantify the results, one performance index, which assesses the quality of the network voltage has been introduced.