Confirming this (just did the calcs and was about to post, and then I saw that its already been posted). Someone asked if it boosts the user's own SpA - it doesn't and doesn't seem to have any apparent use in singles. Also, as the boost is applied to the stat and not the damage, the resultant damage numbers are a bit different from, say, Life Orb. Consequently, it also works with moves like Psyshock and Secret Sword, as their damage depends on SpA.Edit: posting here for records. Battery boosts SpA of the ally by 1.3x
Although Dazzling blocks moves called by a Prankster 'mon using stuff like Metronome and Assist, if a Prankster 'mon uses Instruct or After You to make its ally attack in the +1 priority bracket, that attack is not blocked by the foe's Dazzling.