Bauer 20V to Makita 18V Battery Adapter

Use your Bauer 20V batteries on Makita 18V LXT cordless tools, without buying into a second battery platform. Built with a durable injection-molded ABS housing and pure copper contacts for steady current delivery. This helps you get the most out of your existing battery system while avoiding the cost of another set of batteries and chargers.

Specifications

• SKU PTA-BAU20-MAK18
• Fits this battery Bauer 20V (Lithium-Ion) from Harbor Freight
• Battery voltage 20V
• Runs these tools Makita 18V LXT (Lithium-Ion)
• Tool voltage 18V
• Housing ABS (Injected)
• 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 101 g (3.6 oz / 0.22 lb)
• Colour Black
• Operating humidity 5–95% RH
• Operating temperature -10 °C to 50 °C (14 °F to 122 °F)
• USB port Yes
• What's in the box Battery adapter
• Warranty 12 months after the date of delivery
• Revision Revision 01 (released on February 28, 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.
• 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.
• A USB port on the adapter, so the same battery charges a phone on site.
• Made for the Bauer 20V batteries sold at Harbor Freight, so the fit is the one you already own.
• Covered by a 12-month warranty from the day it arrives.

Bauer 20V and Makita 18V LXT compatibility

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

Compatibility can vary with the exact battery and tool model. Before ordering, confirm that your battery belongs to the Bauer 20V platform and that your tool takes Makita 18V LXT batteries.

Important charging and safety information

This adapter is for powering cordless tools and nothing else. It cannot charge Bauer or Makita 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 Bauer 20V battery.