Battery for Senco tools 14.4v 3000mAh 3.0Ah Ni-MH Replacement

The battery Senco 14.4v 3000mAh 3.0Ah Ni-MH has a capacity of 3000 milliampere hours. This indicates the current of the battery and is indicated by Ah or mAh. Is the capacity high? Then it takes a long time before the battery of your 14.4v 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!