Ryobi 36V/40V to Milwaukee 18V Battery Adapter

Use your Ryobi 36V/40V batteries on Milwaukee M18 cordless tools, without buying into a second battery platform. Your Ryobi 36V/40V battery is 40V and a Milwaukee M18 tool expects 18V. The converter holds the output at the tool’s level for as long as the battery lasts. Constructed from durable molded ABS with pure copper contacts, for a secure fit and dependable current transfer. Fewer battery systems in the workshop, on the bench or in the van, and no extra chargers to find room for.

Specifications

• SKU PTA-RYO40-MIL18
• Fits this battery Ryobi 36V/40V (Lithium-Ion)
• Battery voltage 36V/40V
• Runs these tools Milwaukee M18 (Lithium-Ion)
• Tool voltage 18V
• Housing ABS (Injected)
• Terminals Copper
• Current rating 60A continuous (100A peak at 18VDC for up to 2 seconds)1080 Watt continuous at 18V nominal
• Internal wiring 6 mm²
• Weight 147 g (5.2 oz / 0.32 lb)
• Colour Black
• Operating humidity 5–95% RH
• Operating temperature -10 °C to 50 °C (14 °F to 122 °F)
• USB port No
• What's in the box Battery Adapter
• Warranty 12 months after the date of delivery
• Revision Revision 01 (released on August 9, 2026)

Why choose this adapter

• Injection-moulded ABS, not 3D printed — no layer lines to split under load.
• Solid copper terminals, so less of the current is lost as heat.
• 6 mm² internal wiring, rated for 60A continuous with 100A 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.

Ryobi 36V/40V and Milwaukee M18 compatibility

It works in one direction only: Ryobi batteries powering Milwaukee tools. For the opposite pairing, see adapters that run on Milwaukee M18 batteries.

Compatibility can vary with the exact battery and tool model. Before ordering, confirm that your battery belongs to the Ryobi 36V/40V platform and that your tool takes Milwaukee M18 batteries.

Important charging and safety information

This adapter is for powering cordless tools and nothing else. It cannot charge Ryobi or Milwaukee 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 Ryobi 36V/40V battery.

Before you buy