Bauer 20V to Chicago Electric 18V Battery Adapter

Use your Bauer 20V batteries on Chicago Electric 18V cordless tools, without buying into a second battery platform. The battery side is injection-molded ABS and the tool interface is high-precision 3D-printed ABS for an accurate fit, with pure copper contacts carrying the current. 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-CHI18
• Fits this battery Bauer 20V (Lithium-Ion) from Harbor Freight
• Battery voltage 20V
• Runs these tools Chicago Electric 18V (Lithium-Ion) from Harbor Freight
• 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 131 g (4.6 oz / 0.29 lb)
• Colour Black, Yellow
• 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 February 22, 2026)

Why choose this adapter

• 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.
• 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 Chicago Electric 18V compatibility

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

Important charging and safety information

This adapter is for powering cordless tools and nothing else. It cannot charge Bauer or Chicago Electric 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.