I don't know if you are still looking but here goes...

I've owned Makita, DeWalt, Bosch, and Panasonic. For overall use, the best has been the Panasonic. 15.6 volts is not 18 or 24 but the key is the amphour rating 3.0-3.5! Usefull 15.6v for a comparitively ... Login to read more.