Milwaukee M18 Battery To Harbor Freight Bauer 20V Tools

thingiverse

Adapts Milwaukee M18 battery packs to Harbor Freight Bauer 20V cordless tools. No warranty-voiding tool modifications required, features a 10kΩ resistor in the adapter to fake the thermistor. The thermistor is a safety feature with lithium batteries to prevent overheating and fire. Do not overly discharge your batteries during use. Not for charging. Do not taunt Happy Fun Ball. Absolutely no warranties expressed or implied. Use this design at your own risk! i have a number of Milwaukee M18 tools, batteries and chargers. The Bauer tool line from Harbor Freight has some rather nice tools available at an attractive price point, but I have no desire to own and maintain a second battery ecosystem. There are a number of tools either not available from Milwaukee, or that I need infrequently enough that I cannot justify paying Milwaukee prices. There are adapters sold for this on eBay and Amazon, but they cost more than some of the Bauer tools which negates the cost savings. So, I made my own adapters. Additional parts required: 1 M3x16 flathead screw 4 M3x12 flathead screws 5 M3 heatset inserts 2 male 0.250 "quick connect" terminals (interfaces with M18 battery) 3 female Pico 1598D "ATO Fuse Block" terminals (interfaces with Bauer tool) 1 10kΩ resistor, 1/4W-1/2W (there's no appreciable current through this) wire, solder, epoxy The Pico terminals need modification to fit the cavities but it's fairly evident what to trim or bend away for clearance on assembly. The connector for the Bauer tool's "TH" terminal is soldered to the 10kΩ resistor, which has the other end soldered to the "-" terminal. Male 0.250" terminals on the M18 side are soldered to the wire and epoxied in place after ensuring they're positioned correctly to mate with the battery. Fishing the wires through the print is a little tricky but not difficult. Longer screw is for the battery latch and sandwiches all parts of the adapter together for strength. I used flat head socket screws since I had them, but any flat head M3 screws will work as long as they're the correct length. Photos taken before applying epoxy to show the resistor bridging the "TH" and "-" terminals. This is partially based on 05WEL's "Ozito battery to Xfinity (Aldi) battery adaptor" at https://www.printables.com/model/206655-ozito-battery-to-xfinity-aldi-battery-adaptor and partially based on AgentGene's "M18 to black & decker 18v adapter" at https://www.thingiverse.com/thing:2882736. At this point just about all of the sources have been reworked and remodeled, but credit where credit is due. This adapter also physically fits Harbor Freight's Hercules 20V line, but at least in the impact driver I tested with it didn't allow the tool to work. Your Mileage May Vary.