<p>The invention aims at providing a gelling agent for batteries which can form a pasty gel which little suffers from bubble inclusion and has a high gel density in a short time when dissolved in an alkaline electrolytic solution. A gelling agent for batteries which consists of carboxyl -containing polymer granules having a median particle diameter of 100 to 800µm and a bulk density of 0.30g/ml or above and which gives a gel having a turbidity of 200ppm or below and a gel density of 1.37g/ml or above when 2 parts by mass of the carboxyl -containing polymer granules is added to 98 parts by mass of a 40 mass% aqueous solution of potassium hydroxide.</p>
