If you are flexible with your travel dates, always consider that you can buy extremely cheap train tickets if you avoid travelling in the weekends and if you choose to travel during the low season.
If the train timetable doesn't fit in your schedule or budget, bus and carpooling can provide you some time and price alternatives, without substantially changing the duration of the journey.
Which stations serve the rail line Charleroi - Liège?
You can take the train to Liège at Charleroi-Sud / Charleroi-Zuid, which arrives at Liège-Guillemins / Luik-Guillemins.
How long does it take from Charleroi to Liège and when do the trains leave?
With the fastest connections you will be in Liège in 2 hours and 4 minutes, but on average it takes 2 hours and 32 minutes. The first train headed to Liège is at 05:11, while the last one leaves Charleroi at 18:11.