Milwaukee 18V to MacNaught 18V Battery Adapter (Pump, Grease Gun)

Use your Milwaukee M18 batteries on MacNaught 18V cordless tools, without buying into a second battery platform. Voltage is not the obstacle here — both sides are 18V. The socket is, and that is what this solves. Built with an injection-molded ABS battery interface, a 3D-printed ABS tool socket for a close fit, and pure copper contacts. It keeps one battery platform serving more tools, which costs less than buying into another. It also carries battery protection electronics (BMS) inside.

Specifications

• SKU PTA-MIL18-MNA18
• Fits this battery Milwaukee M18 (Lithium-Ion)
• Battery voltage 18V
• Runs these tools MacNaught 18V (Lithium-Ion)
• Tool voltage 18V
• Housing ABS
• Terminals Copper
• Current rating 40A continuous (80A peak at 18VDC for up to 2 seconds)720 Watt continuous at 18V nominal
• Internal wiring 5 mm²
• Weight 109 g (3.8 oz / 0.24 lb)
• Colour Red, Black
• Operating humidity 5–95% RH
• Operating temperature -10 °C to 50 °C (14 °F to 122 °F)
• USB port No
• Built-in BMS protection Yes
• What's in the box Battery adapter
• Warranty 12 months after the date of delivery
• Revision Revision 01 (released on December 27, 2025)

Why choose this adapter

• Your Milwaukee M18 battery and MacNaught 18V tools run at the same voltage, so the adapter changes the fitting rather than converting anything.
• A Battery Management System inside the adapter cuts power before the battery is drained too far — protection your battery may not have on its own.
• Solid copper terminals, so less of the current is lost as heat.
• 5 mm² internal wiring, rated for 40A continuous with 80A peak at 18VDC for up to 2 seconds, so a high-draw tool is not held back by the adapter.
• Covered by a 12-month warranty from the day it arrives.

Milwaukee M18 and MacNaught 18V compatibility

It works in one direction only: Milwaukee batteries powering MacNaught tools. For the opposite pairing, see adapters that run on MacNaught 18V batteries.

Compatibility can vary with the exact battery and tool model. Before ordering, confirm that your battery belongs to the Milwaukee M18 platform and that your tool takes MacNaught 18V batteries.

Important charging and safety information

This adapter is for powering cordless tools and nothing else. It cannot charge Milwaukee or MacNaught batteries and must never be connected to a charger of any kind. Always take the battery out of the adapter before charging, and charge it on the original charger made for your Milwaukee M18 battery.