9 V Battery has the least current than 1.5 V AA Battery.
Explanation:
A standard 9 V battery has about 400-600 mAh capacity. In the most basic terms, these batteries can supply about 500 milliamps for one hour before being "dead".
Normal AA/AAA batteries that have a voltage rating of 1.5 V can supply constant 50 mA current for a total capacity of 1800-2600 mAh.
Therefore 9 V Battery which have current around 400-600 mAh capacity has the least current than 1.5 V AA Battery which have 1800-2600 mAh capacity.
