Makita 197280-8 Akku-BL1850B Li 18,0V 5.0Ah, 5 W, 18 V, Schwarz

I've had a few "compatible" batteries from other brands, but I've found the hard way that the original Makita batteries last longer. They're also slightly smaller for the same capacity. I love how the little charge indicator on the back has 4 clear LED segments that stay on for a little bit when you press the charge status button. That helps make it easy to read if my fat finger is in the way. They also shutdown properly at the end and don't over discharge like some off-brands. These batteries aren't the least expensive (I wish they were), but time and again it's been worth it to have original Makita batteries.