This work comprises an experimental study on various factors affecting the stability of "partly covered" photoelectrochromic (PEC) devices. The fabricated devices were stored in the dark at open circuit conditions and at regular time intervals, transmittance spectra for coloration and bleaching were taken and I-V measurements were conducted. This methodology revealed that the PEC devices, after passing a transitional period of about 10 days post fabrication, seem to stabilize or to decay at a lower rate. The annealing temperature of the anode and the composition of the electrolyte affect drastically the operation and stability of the devices. By annealing the anode at 350 degrees C for 40 min and using a commercial electrolyte, developed for high performance dye sensitized solar cells, stable devices were fabricated (nearly 10 months of shelf life), but with reduced reversibility. In order to improve the reversibility two different strategies were tried. The first one was the electrochemical treatment of the anode, before incorporation into the device, and the other was to alter the composition of the electrolyte. Reversible devices with shelf life exceeding 5 months were fabricated using an anode annealed at 100 degrees C and an electrolyte consisting of 0.5 M LiI/0.005 M I-2/0.5 M 4-TBP/ACN. Electrolytes specifically designed for PEC devices need to be developed for optimum operation. (C) 2015 Elsevier B.V. All rights reserved.