This work improves the accuracy of longitudinal thermoelectric energy harvesting (LTEH) models introducing the prediction of the interconnection effects. LTEHs are composed of multiple arrays of thermoelectric generators (TEG) electrically arranged in series-parallel configuration. The way that TEG modules are connected strongly affects the electro-thermal outputs of each module and the whole harvester as well. In this paper, a new computational model capable to simulate the electro-thermal dynamics of a longitudinal thermoelectric energy harvester have been developed. It is composed of an array of interconnected TEG modules, which, at the same time, can be disposed thermally and electrically in different series-parallel configurations. The comparison of results between theoretical and experimental data shows great accuracy and the possibility to be used as a simulation tool. The root mean square errors RMSE for electrical power generated and system efficiency are 2.9 mW and 2.15 x 10(-4)%. Additionally, the normalized root mean square errors NRMSE are 0.75% and 0.52%. (C) 2017 Elsevier Ltd. All rights reserved.