Every time Makita improves their battery technology, they change the way the battery fits to the tool with no backwards compatability. So I have an older circ saw, a recip saw and a couple others and no Makita battery to power them. I've been hesitant to grind away parts of the old tools' battery seat. John (Dabbler) came up with a Rube Goldberg solution. I bought an adaptor from the 18 volt Makita tool to 18 volt Milwaukee battery. Then I bought an adaptor from the 18 volt Milwaukee tool to an18 volt Makita battery. Eureka it worked. Now I can use newer style 18 volt Makita batteries on my older Makita tools.