Bauer 20V to Milwaukee 12V Battery Adapter
327,00 kr
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Bauer 20V to Milwaukee 12V Battery Adapter
327,00 kr
Taxes included.
kr 35.00 Shipping to NorwayZero customs fees. Zero surprise taxes.
Safety feature
Built-in BMS Protection
Integrated Battery Management System (BMS) helps prevent battery over-discharge and improves safety.
Use your Bauer 20V batteries on Milwaukee M12 cordless tools, without buying into a second battery platform. The battery sits above the tool’s platform — 20V against 12V — so this adapter converts instead of connecting the two directly. The molded ABS housing keeps it light and hard-wearing, and pure copper contacts keep current delivery steady. Fewer battery systems in the workshop, on the bench or in the van, and no extra chargers to find room for. It also carries battery protection electronics (BMS) inside.
Specifications
- SKU
- PTA-BAU20-MIL12
- Fits this battery
- Bauer 20V (Lithium-Ion)from Harbor Freight
- Battery voltage
- 20V
- Runs these tools
- Milwaukee M12 (Lithium-Ion)
- Tool voltage
- 12V
- Housing
- ABS (Injected)
- DC-DC converter
- Yes — 20V to 12V
- Terminals
- Copper
- Current rating
- 40A continuous (80A peak at 18VDC for up to 2 seconds)432 Watt continuous at 10.8V nominal
- Weight
- 142 g (5.0 oz / 0.31 lb)
- Colour
- Black, Red
- 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 deliveryMore details
- Revision
- Revision 01 (released on August 20, 2026)
Why choose this adapter
- 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.
- 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.
- 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 Milwaukee M12 compatibility
It works in one direction only: Bauer batteries powering Milwaukee tools. For the opposite pairing, see adapters that run on Milwaukee M12 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 Milwaukee M12 batteries.
Important charging and safety information
This adapter is for powering cordless tools and nothing else. It cannot charge Bauer 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 Bauer 20V battery.
How it works
-
1. Use the battery you own
Any compatible Bauer 20V battery you already have.
-
2. Slide on the adapter
It goes where the original Milwaukee M12 battery sits.
-
3. Click in and work
No tools, no wiring, no modifications.
Bauer 20V to Milwaukee M12 — Common Questions
My battery says 20V. Can it run a tool rated differently?
Yes, and they are closer than the labels suggest. 20V is what a Bauer 20V battery measures off the charger with no load; 18V is what it holds in use. Milwaukee M12 tools are built around 10.8V. The two numbers describe the same class of battery, which is why the adapter works rather than merely fits.
Will my Milwaukee M12 tool run as long on a Bauer 20V battery?
Runtime comes from the battery, not the adapter — a 5.0Ah Bauer 20V battery lasts roughly twice as long as a 2.5Ah one, exactly as it would on its own tool. The adapter’s copper terminals and heavy-gauge wiring are there to keep resistive loss low.
Could this damage my Bauer 20V battery or my Milwaukee M12 tool?
Used with undamaged, compatible equipment it is not expected to. This adapter has its own Battery Management System, which cuts power before the battery is drained too far, so it protects the battery even where the battery has no protection of its own. Stop using it if the adapter becomes unusually hot, the contacts look damaged, or the tool behaves oddly.
Can I charge through the adapter?
No, and it should never be attempted. The adapter carries power one way only, out to the Milwaukee M12 tool — there is no charging circuit inside it. Connecting it to a charger puts the battery, the charger and the adapter at risk. Always take the Bauer 20V battery off the adapter and charge it on its own charger.
My Bauer 20V gear came from Harbor Freight. Is that the same platform?
Yes — Harbor Freight is where Bauer 20V is sold, so a battery or tool bought there is the platform this adapter is built for. What matters is the socket, and Harbor Freight stock is the reference for it.
Does it work with third-party Bauer batteries?
Usually. What matters is the socket, not the badge: if the battery slides on and locks the way an original does, the adapter takes it and the Milwaukee M12 tool runs. Aftermarket moulding does vary, so if yours looks unusual send us a photo and we will check before you order.
How much does it add to the Milwaukee M12 tool?
142 g (5.0 oz) and a short extension between battery and tool. You notice it overhead or in a tight cabinet; on a drill or driver held normally it disappears.