Milwaukee's M12 and M18 batteries are part of their cordless power tool lineup and offer different power and compatibility options. Here are the key differences between the M12 and M18 battery systems:

  1. Voltage and Power: The M12 battery system operates at 12 volts, while the M18 battery system operates at 18 volts. As a result, M18 batteries generally provide more power and are suitable for heavier-duty applications compared to M12 batteries.

  2. Tool Compatibility: The Milwaukee M12 battery system is designed specifically for Milwaukee's M12 line of power tools. Similarly, the M18 battery system is intended for use with Milwaukee's M18 line of power tools. It's important to note that M12 batteries are not compatible with M18 tools and vice versa.

  3. Tool Size and Weight: Since M12 batteries are smaller and operate at a lower voltage, tools using M12 batteries tend to be more compact and lightweight compared to tools using M18 batteries. This can be advantageous in situations where portability and maneuverability are important.

  4. Runtime and Capacity: Generally, M18 batteries have higher capacity and longer runtime compared to M12 batteries due to their higher voltage. This makes M18-powered tools better suited for demanding tasks that require extended use without frequent battery changes.

  5. Tool Selection: While both the M12 and M18 systems offer a wide range of power tools, it's worth noting that the M18 system has a broader selection of tools available, including larger and more powerful tools suitable for heavy-duty applications. The M12 system, on the other hand, is often preferred for lighter tasks or situations where compactness is prioritized.

When choosing between the Milwaukee tools M12 and M18 battery systems, consider the type of tasks you'll primarily be using the tools for, as well as your preference for tool size, weight, and power. If you already own tools from either system, it's generally recommended to stick with the corresponding battery system to maintain compatibility.