Most 20V batteries are interchangeable only within one brand’s own 20V platform — a DeWalt 20V MAX pack fits DeWalt 20V MAX tools, but not Black+Decker, Craftsman, Milwaukee, or Makita tools.
For the full breakdown, see our best 20 Volt Battery guide.
A “20V” sticker is a marketing label, not a universal fit — the plastic rails and connector pins on each brand are shaped differently on purpose. That means the single biggest mistake a shopper makes is grabbing a 20V pack off a shelf and assuming it belongs in a different color tool.
The good news is that within a brand, the 20V system is remarkably flexible. DeWalt 20V MAX batteries work in every DeWalt 20V MAX tool, and DeWalt’s higher-voltage FLEXVOLT packs also drop into those same tools. So the compatibility question has a clear answer once you know which platform you own.
Do All 20V Batteries Fit All 20V Tools?
No — matching voltage numbers do not make two batteries interchangeable. Compatibility runs on the brand’s specific platform name, not the number printed on the side.
Every major maker builds a physical interface — rails, terminal block, and an electronic handshake — that only its own packs satisfy. Put a DeWalt 20V MAX battery next to a Craftsman V20 pack and the shape alone tells the story: the contact block sits in a different spot, so the battery won’t seat.
Because the tool and battery also talk electronically, a mismatched pack has more problems than a loose fit. Even when a battery physically slides on, the tool’s circuitry may refuse to run or may not protect the cells correctly. That’s why the honest rule is simple: buy into one platform and stay there.
Which Brands Actually Share Batteries?
True interchangeability lives inside a single brand’s own voltage platform — not between brands, and not even between sibling brands under the same parent company. DeWalt 20V MAX packs fit DeWalt 20V MAX tools only, and the same is true for each competitor.
The one useful cross-compatibility inside a family is DeWalt’s FLEXVOLT line. A FLEXVOLT battery powers DeWalt 60V tools and, on its own, steps down to run standard 20V MAX tools — so one pack can serve both. That flexibility doesn’t travel: FLEXVOLT is a DeWalt product for DeWalt tools.
Flagship 20V systems from competing brands are all proprietary:
- DeWalt 20V MAX — fits DeWalt 20V MAX tools; FLEXVOLT also works here; standard 20V MAX packs cannot run DeWalt 60V or 120V tools.
- Black+Decker 20V MAX — shares the name, not the fit; no swap with DeWalt.
- Craftsman V20 — its own platform; no swap with DeWalt.
- Milwaukee M18 — 18V, its own interface; not directly compatible with DeWalt.
- Makita LXT 18V — its own platform; no swap with DeWalt.
The takeaway repeats across every pair: same parent company, same voltage number, and still no shared connection.
If you’re weighing a fresh pack, a tested 20 volt battery roundup that compares real-world capacity and runtime across these platforms is worth a look before you commit.
| Platform | Swap With | Notes |
|---|---|---|
| DeWalt 20V MAX | DeWalt 20V MAX tools | FLEXVOLT packs also fit; no 60V/120V output from standard packs |
| Black+Decker 20V MAX | Black+Decker 20V MAX only | Not interchangeable with DeWalt despite the shared name |
| Craftsman V20 | Craftsman V20 only | Not interchangeable with DeWalt 20V MAX |
| Milwaukee M18 | Milwaukee M18 only | 18V system; not directly compatible with DeWalt |
| Makita LXT 18V | Makita LXT only | Not interchangeable with DeWalt |
| FLEXVOLT | DeWalt 20V MAX + 60V tools | Auto-switches to 20V in compatible 20V MAX tools |
Are Battery Adapters Worth Using?
Adapters let some brand pairs connect, but an adapter is not the same as native compatibility and no major manufacturer officially supports cross-brand swapping of standard 20V slide-on packs.
A third-party shoe may bridge one brand’s tool to another brand’s battery, yet it doesn’t rewrite how the two systems communicate. The tool may lose low-voltage cutoff, temperature protection, or fuel-gauge feedback, because the pack’s electronics are still speaking a language the tool doesn’t understand. Mismatched connections can also keep a pack from seating fully, which is its own risk.
For everyday work, the dependable path is to match the exact platform name — DeWalt 20V MAX, Milwaukee M18, Makita LXT 18V, Craftsman V20 — rather than trusting a voltage match or an adapter to solve it. Buying the correct pack for your platform costs less headache than nursing a workaround.
The DeWalt battery compatibility overview is a solid reference for how the 20V MAX and FLEXVOLT lines relate to each other.
References & Sources
- Mister Worker. “Are DeWalt Batteries Interchangeable?” Explains DeWalt 20V MAX and FLEXVOLT cross-compatibility within the brand.
- Tool Compatibility. “Battery Compatibility Guide.” Details which brand platforms do and do not share batteries.
- Tool Compatibility. “Power Tool Battery Compatibility FAQ (2026).” Covers common cross-brand compatibility questions and adapter limits.
