In recent years DC micro-grid has been widely accepted as one of the promising solutions to integrate renewableenergy sources and to supply power to critical loads such as data centres, remote villages and communication stations.However, DC micro-grid has a fundamental stability challenge due to constant power load (CPL) characteristics of point-ofloadconverters, which introduce destabilising effect in the system. This study presents a sliding mode control based nonlinearcontrol scheme for a solar photo-voltaic based DC micro-grid in the presence of CPLs. The objective of the proposedcontrol scheme is to tightly regulate the DC bus voltage and mitigate the destabilising effects of CPLs. The stability of thesystem is analytically established and a limit of CPL is obtained. Furthermore, a charging/discharging algorithm isimplemented for battery bank interfacing bidirectional converter which facilitates three modes charging namelyconstant current, constant voltage, and float mode, to enhance the battery life. The validation of the effectiveness ofthe proposed scheme is done through simulation and experimental results. It is found that the proposed controlscheme ensures desired operation of the DC micro-grid under various operating modes and maintains system stabilitywith CPL under variations in the primary resource and load demand. © The Institution of Engineering and Technology 2017.