7.2v battery for Wolf Garten tools

The Wolf-Garten 7.2v 3000mAh 3.0Ah Ni-MH battery has a capacity of 3000 milliampere hours. This indicates the current of the battery and is indicated as Ah or mAh. Is the capacity high? Then it takes a long time before the battery of your Wolf-Garten 7.2v tool is empty. Is mAh lower? Then you will have to charge the battery more often. With more mAh your machine does not become more powerful!