What H-bridge do I need for my setup?
Based on your last edit, your battery pack is not a 12V battery, it's an array of 18 3.7V cells that give you 54000mAh with 3.7V output, the regulator it has is actually a step up regulator, so it converts your 3.7V in a 12-24Vdc, what you would need us a step up regulator that can boost 3.7V into 24V with at least 20A