Did the Companions fast in the Battle of Badr? And when was fasting the month of Ramadan made obligatory?

Ramadan fasting was prescribed in the second year of the Hijra, and the Prophet, peace and blessings be upon him, fasted nine Ramadans. He used to command his companions to break their fast when they approached the enemy, to strengthen them for fighting, as happened in the battles of Badr and the Conquest (of Mecca), where they broke their fast. Although the chain of narration for the hadith of Umar in Tirmidhi is weak, some scholars have graded it as hasan (good) and considered it authentic, which confirms breaking the fast in the Battle of Badr to repel the enemy.