Based on a previous approach for the modelling of piezoelectric monomorph benders, a new, more complete, analytical model is proposed. Some previously neglected features of the actuator stack, notably the thickness of the electrodes and the presence of isolation layers at the top and bottom of the stack, were taken into account in this new iteration. The demonstrated model takes the form of a system of two constitutive equations describing the mechanical and electrical state of the actuator. This model is then experimentally validated in a test environment measuring the beta parameter of a custom made actuator for which the initial model presented errors. The results of these measurements show that the estimation error of the beta parameter for this particular actuator design has been brought down from 69% to 3%, demonstrating that the inclusion of the previously neglected features leads to an accurate analytical model, paving the way for a proper optimisation study.