brudno - 4/30/2015 21:24

Batteries are not always interchangeable there are quite a few different generations of batteries the latest batteries will work in all the tools from the latest to the first m18's but the older batteries wont always work in the newer tools, especially the fuels, they use different batteries. You cant physically install the wrong battery though, the tools have tabs that wont allow the older batteries to be installed. There still the best cordless tools on the market its more of a statement of how innovative and advanced there new tools are vs tools they were putting out even just a year or two ago and the different power requirements.