Question about DeWalt DCG406NT-XJ (125 mm) Cordless angle grinder 125 mm, 18 V (basic v.)

I have 2 rechargeable batteries 18 V / 2.0 Ah and the charger DCB113 from a previous purchase for a cordless drill. Now I have bought the DCG406-XJ cordless angle grinder without the battery. Are the existing 2.0 Ah batteries sufficient for this or should it be a higher capacity? The first time I used a fully charged small battery, the battery life was not so good.