Your toolbox is DeWalt 20V MAX, but a mate’s Milwaukee M18 cordless nailer or rotary hammer would make quick work of a job. Rather than renting or buying a whole new battery platform, a DeWalt to Milwaukee adapter bridges the gap. DEWALT gives 18V as the nominal voltage of its 20V MAX batteries, matching the 18 in Milwaukee’s M18 name, and an adapter lets you use your existing DeWalt batteries in Milwaukee M18 tools.
This guide reviews the best DeWalt to Milwaukee adapters available in the UK, explains the mechanics, covers which batteries work, and outlines important practical considerations.
Watch: Video Guide
How DeWalt to Milwaukee Adapters Work
DEWALT’s “20V MAX” is the maximum initial voltage; the nominal voltage is 18V, matching the 18 in Milwaukee’s M18 name. The batteries differ in shape and contacts, and we have no maker source saying they behave identically.
A DeWalt to Milwaukee adapter fits onto your DeWalt battery and presents an M18-style interface to a Milwaukee M18 tool. We have not verified what circuitry a given adapter contains. Use adapters for tool use only: do not charge a battery through one.
An adapter adds a substantial amount of stack height — published dimensions for the common generic adapters put the added depth at roughly 40–90mm. This is rarely problematic, but always check fit before committing to tight spaces, ladder work, or placing the battery in restrictive storage locations like van shelving or tool bags.
Best DeWalt to Milwaukee Adapters
Badaptor DEW-MIL (Discontinued)
Update: Badaptor has announced that it is discontinuing the range and taking down its website; it has not said what happens to warranty support for existing units. UK retailer Tooled-Up lists this model as delisted and no longer available.
The Badaptor DEW-MIL was sold as a DeWalt-battery-to-Milwaukee-tool adapter. With the maker’s site closing, we could not check its construction or warranty terms.
Priced at approximately £23–29.
Buy Badaptor DEW-MIL on Amazon
DL18ML Adapter (Best Value)
The DL18ML is sold as a DeWalt 20V MAX battery to Milwaukee M18 tool adapter. It is priced at £18–24.
We found no warranty terms we could check.
POWHAZY MWK005A (Wrong Direction)
The POWHAZY MWK005A is sold as a Milwaukee-battery-to-DeWalt-tool adapter, the opposite direction to this guide, so it will not let you use DeWalt batteries in Milwaukee tools; Amazon UK also showed it as currently unavailable on 24 October 2026. For DeWalt batteries in M18 tools, the DL18ML above is the model we could confirm.
Check DL18ML adapter listings on Amazon
Comparison Table
| Adapter | Design Type | Price Range | Build Quality | Warranty | Best For |
|---|---|---|---|---|---|
| Badaptor DEW-MIL | Not confirmed (discontinued) | £23–29 | Not checked | Not confirmed | Discontinued; remaining stock only |
| DL18ML | DeWalt battery to Milwaukee tool | £18–24 | Not checked | Not stated | DeWalt batteries in M18 tools |
| POWHAZY MWK005A | Milwaukee battery to DeWalt tool (wrong direction) | £17–22 | Not checked | Not stated | Not for this job |
Recommended Batteries
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Before you buy: check that the size, fitting/bore and maximum-rated speed marked on the accessory match what your tool’s manual specifies. We have not physically tested these products; listings are compiled from published specifications. These are affiliate links.
Get the free Power-Tool Battery Compatibility Handbook (PDF)
Which batteries fit which tools — cross-brand, adapters & Ah, decoded.
Compatible DeWalt 20V MAX Batteries
DeWalt 20V MAX battery models that adapter listings commonly name are listed below; check the listing for the exact models it covers, as we have not verified them:
- DCB206 — 6.0Ah, the largest of these packs
- DCB205 — 5.0Ah, versatile mid-capacity option
- DCB204 — 4.0Ah, compact and lightweight
- DCB203 — 2.0Ah, a compact pack for low-draw tools
- DCB201 — 1.5Ah, the smallest of these packs
FLEXVOLT: DeWalt says its XR FLEXVOLT batteries are backwards compatible with its own 18V XR (US: 20V MAX) tools, switching voltage automatically. DeWalt says nothing about running them through a third-party adapter in another brand’s tool, and we have not verified it. FLEXVOLT packs are also larger and heavier, so check the fit first.
Compatible Milwaukee M18 Tools
Listings for these adapters say they fit Milwaukee M18 tools such as the following; we have not verified any combination:
- Cordless drills and drivers (standard M18 CompactDrill, M18 XC)
- Impact drivers and wrenches
- Circular saws and reciprocating saws
- Angle grinders
- Nailers (friction-ring and straight-finish models)
- Rotary hammers and SDS drills
- Blowers and fans
Not compatible: Milwaukee M12 is a different, 12V platform. Milwaukee’s MX FUEL equipment is a separate system too. Stick to M18 tools.
Important Limitations
No charging through the adapter: do not charge a battery through a third-party cross-brand tool-use adapter. Always use a DeWalt charger for DeWalt batteries.
Height adds up: The extra height (roughly 40–90mm on the generic adapters whose dimensions are published) can be problematic in scaffold tool bags, tight van compartments, or when securing the battery in a power tool trays. Test fit before committing to a job where space is tight.
Use on M18 tools only: do not use a DeWalt-to-Milwaukee adapter on Milwaukee M12 tools or on any other non-M18 Milwaukee system. Stick to tools marked “M18”.
Contact degradation: Every connection and disconnection slightly wears the adapter’s internal contacts and the battery’s spring terminals. Periodically inspect for black corrosion on the contacts or visible cracks on the adapter body. Replace the adapter if contacts become heavily oxidised or if the clip loosens.
Frequently Asked Questions
Will my DeWalt battery work in a Milwaukee M18 tool with this adapter?
Adapter listings say so, but we have not verified any combination or tool- and battery-maker approval for these adapters. DEWALT gives 18V as the nominal voltage of its 20V MAX batteries, matching the 18 in Milwaukee’s M18 name, but similar voltage does not establish compatibility or that the protection functions between battery and tool still work.
Can I charge my DeWalt battery in a Milwaukee charger with the adapter?
No. Do not charge a battery through a third-party cross-brand tool-use adapter. Use a charger expressly specified by the battery maker — for a DeWalt battery, a DeWalt charger.
Do these adapters work with Milwaukee M12 tools?
No. Milwaukee M12 is a different, 12V platform. A DeWalt-to-Milwaukee adapter is sold for M18 tools, so use it only on M18 tools.
Will a DeWalt FLEXVOLT battery work in a Milwaukee M18 tool with an adapter?
DeWalt says its XR FLEXVOLT batteries are backwards compatible with its own 18V XR (US: 20V MAX) tools, switching voltage automatically. DeWalt says nothing about running them through a third-party adapter in another brand’s tool, and we have not verified it. FLEXVOLT packs are also larger and heavier, so check the fit first.
Which adapter is best for occasional use?
We have not tested any adapter, so we can’t rank them on reliability. The DL18ML (£18–24) is the DeWalt-to-Milwaukee model we could confirm; Badaptor is discontinued, and the POWHAZY MWK005A works in the opposite direction (Milwaukee battery to DeWalt tool).
Can I use the adapter with Milwaukee’s M18 FUEL tools?
M18 FUEL tools are part of Milwaukee’s M18 range, so an adapter sold for M18 tools is meant to fit them, but we have not verified any combination. FUEL tools are often used for heavier work, so we suggest a larger pack (such as the DCB206) over the DCB201 or DCB203.
Related battery platforms: DeWalt 20V MAX Battery Compatibility | Milwaukee M18 Battery Compatibility
How we compile this guide
We cross-reference compatibility details against manufacturer specifications where available, official tool manuals, and the physical standards that govern fitment (bore sizes, arbor diameters, voltage platforms, connector types). We prioritise primary sources over retailer listings, flag anything we can’t confirm, and re-verify the data on a regular cycle. Where we give a buying recommendation, we tell you the reasoning — not just the link. More on our method →
