Everyone is complaining that the M18 batteries are no longer really compatible. The new power tool won't run right without the 12A batteries. Its been that way ever since the 4A battery came out. No one is gonna toss the 12A battery on the Surge and run that all day. You'll have forearms like Popeye. And also no one will take the original 1.5A battery and put it on the Fuel circular saw, much less the table saw. Are they compatible? Eh, I guess so, but each tool has the ideal battery for it. The little ones for the impacts, the 4.0 and 5.0 for the hammer drill, circ saw, grinder, etc, the 9.0 for the OPE, and now the 12.0 for the new tools. I have no problem with them calling it compatible, because in a pinch, its nice to know that I could put a 4.0 on the new table saw and get that one last cut out of it.