The Yell Battery (きあいバッテリー?) is a treasure exclusive to the Japanese version of Pikmin 2. It is a National Hi-Top C battery. It is found in Perplexing Pool in the same spot that the Optical Illustration and Abstract Masterpiece are found in the US and European versions, respectively.
Collecting the treasure
Olimar and the Hocotate ship's notes for this treasure, when translated, appear to be similar to those of the Fuel Reservoir.