We investigate the effect of light soaking and forward electric bias treatment on SHJ solar cells and modules, and in particular the influence of the thermal treatment occurring during lamination. A substantial performance increase is observed after electric bias or light soaking, which is shown to be potentially partly reset by the lamination process. This reset is reproduced by annealing the cells with the same thermal budget. A second treatment after lamination again improves performances, and a similar final performance is reached independently of the pre-lamination treatment. Therefore, a single treatment after lamination enables maximal module output without any benefit from a cell pre-treatment. Whereas cells react overall better to forward bias, modules show a slightly better response to light soaking.