The Battle of Chamkaur, also known as the Second battle of Chamkaur was a battle fought between the Khalsa, led by Guru Gobind Singh, against the Mughal army and Ajmer Chand’s league of Rajput Hill Chieftains. The period of this Battle in Chamkaur is 21,22 and 23 December 1704 [6,7,8 Poh Samat 1761 Bikrmi]. Guru Gobind Singh with his entourage left Anandpur Sahib at the night of 20 December 1704.
Guru Gobind Singh makes a reference to this battle in the Zafarnamah. He tells how a huge (Dahlakh) army ..the word used to describe the number of Mughal soldiers is “Dahlakh”. It is a Persian word and historians translate it to mean “infinite” or “Ten Lakh”, but a Muslim writer  wrote that the small fort used by the Sikhs was surrounded by 700 cavalry equipped with artillery. In the History Of The Sikhs: Hari Ram Gupta, pp.293. ..
History of the Sikhs mentions 700 cavalry with artillery. However, the number actually is slightly larger because of the uncounted infantry soldiers of the army that drove the artillery. Mughals specialized in cavalry but this was a siege. Hence we expect Mughals to bring a few cannons, driven by large numbers of villagers ( villagers were the basic infantry of Mughal Empire). Other infantry would include the Hindu Bhumi militiamen and matchlockmen. They add to the growing 700. I think we can say with some confidence that this number is approximately a 1000, including 700 horses and perhaps 300 infantry. Unfortunately it cannot be confirmed. Deduced from the “Men at Arms: Mughal Army”. attacked his Sikhs who were only forty in number and without food. In spite of their numerical strength, the Mughal soldiers were unable to kill or capture the Guru. The Guru also talks of cowardice of one of the Mughal generals and how he hid himself behind a wall, not having the courage to face the Guru.