11Now, the acts of Asa from first to last, behold, they are written in the Book of the Kings of Judah and Israel. 12In the thirty-ninth year of his reign Asa became diseased in his feet. His disease was severe, yet even in his disease he did not seek YHVH, but the physicians.
2 Chronicles 16:11,12
1st and 2nd Kings use Jehoshaphat’s 1st sole year of reign [869 BC] following his ascension year of the death of his father to synchronise with the reigns of Israel’s kings, whilst still counting his total reign of 25 years from the beginning of his co-regency when his father became diseased [872 BC] to his own death in the 5th year of the reign of Joram of Israel [848 BC] when his own Jehoram of Judah succeeds in his own right for a further 8 years.