This paper focuses on the platoon formation planning problem for electric commercial vehicles, considering charging constraints. We present a polynomial time heuristic designed to efficiently handle large scale instances. To evaluate its performance, we compare the heuristic with a Mixed Integer Linear Programming (MILP) model in terms of solution quality and computational time. Results show that the heuristic achieves near-optimal solutions for small and medium sized instances and can solve problems involving up to 2,000 vehicles in less than 7 s, while the MILP requires over an hour to solve instances with more than 100 vehicles.