Maybe charging it up was part of a ritual.
With reference to its powers,
In the march from Sinai, and at the crossing of the Jordan, the Ark preceded the people, and was the signal for their advance (Num. 10:33; Josh. 3:3, 6). The Ark of the Covenant burned the thorns and other obstructions in the wilderness roads. According to tradition, sparks from between the two cherubim killed serpents and scorpions. (Canticles iii) [1] During the crossing of the Jordan, the river grew dry as soon as the feet of the priests carrying the Ark touched its waters; and remained so until the priests -- with the Ark -- left the river, after the people had passed over (Josh. 3:15-17; 4:10, 11, 18). As memorials, twelve stones were taken from the Jordan at the place where the priests had stood (Josh. 4:1-9).