Stanley Black & Decker 20V Battery Cross-Compatibility — What Actually Works (2026)

If you’ve ever wondered whether your DeWalt, Black+Decker, Stanley FatMax, Craftsman, or Porter-Cable batteries are interchangeable, you’re not alone. They’re all owned by the same parent company, Stanley Black & Decker. Surely the batteries fit in each other’s tools, right?

The short answer: no. Despite the common ownership, these brands use deliberately incompatible battery platforms. This isn’t an accident—it’s a deliberate strategy to segment the market and protect brand positioning. This guide explains why, what actually is compatible, and which systems matter for UK users.

The Short Answer: No Cross-Compatibility

No, Stanley Black & Decker brands do not share batteries. Each brand has its own connector design, battery management system (BMS), and electronics. A DeWalt 20V MAX battery will not fit in a Black+Decker tool, even though both companies are owned by Stanley Black & Decker.

This is a deliberate design choice. The company maintains separate platforms to keep professional-grade tools (DeWalt) separate from consumer lines (Black+Decker, Stanley), protecting the premium positioning of the DeWalt brand and ensuring each product line operates within its intended market.

The Brands Under Stanley Black & Decker

Here’s a breakdown of each brand’s 20V platform, including connector type and UK availability:

 

BrandLatform NameNominal VoltageConnector TypeUK AvailabilityMarket Segment
DeWalt20V MAX / FLEXVOLT20V (18V nominal)5-slot rectangularWidely availableProfessional / serious DIY
Black+Decker20V MAX / POWERCONNECT20V (18V nominal)4-slot connectorLimited availabilityConsumer / casual DIY
Stanley FatMaxV20 System18V (despite “V20” name)Proprietary connectorUK-focused brandEnthusiast / semi-professional
CraftsmanV20 System20V (18V nominal)5-slot (reversed polarity)Noth America primarilyConsumer / DIY
Porter-Cable20V MAX20V (18V nominal)Unique connectorVirtually unavailable in UKConsumer

Why They’re Not Compatible

There are several reasons why Stanley Black & Decker maintains separate battery platforms across its brands:

Different Connector Designs

Each brand uses a different physical connector to prevent batteries from fitting into incompatible tools. DeWalt 20V MAX uses a 5-slot rectangular connector, while Black+Decker 20V MAX uses a different 4-slot design. Stanley FatMax V20 uses its own proprietary connector. Even though the voltage is nominally the same, the mechanical design prevents accidental mismatches.

Incompatible Battery Management Systems

Each platform has its own battery management system (BMS) hardware and firmware. These systems communicate with the tool to regulate discharge, monitor cell health, and protect against overcharge. A Black+Decker battery’s BMS will not communicate properly with a DeWalt tool, even if you could physically force a connector—which you shouldn’t.

Craftsman Reversed Polarity

To add another layer of incompatibility, Craftsman V20 batteries use reversed polarity compared to DeWalt’s system. This means even if the physical connector were similar, connecting the wrong battery could damage both the battery and the tool.

Market Segmentation

Perhaps most importantly, this incompatibility is deliberate strategy. Professional tradespeople expect DeWalt tools and batteries to be premium-tier equipment. If consumers could use cheaper Black+Decker batteries in DeWalt tools, it would dilute the brand’s positioning. Keeping the platforms separate protects the premium positioning of each brand within its target market.

Third-Party Adapters

Adapters exist that claim to bridge these gaps—for example, adapters that allow a DeWalt battery to physically connect to a Black+Decker tool. However, we do not recommend using them for several reasons:

  • Warranty void: Using an adapter will void the warranty on both the battery and the tool.
  • BMS incompatibility: The tool’s electronics may not communicate correctly with the battery’s management system, risking overcharge or complete failure.
  • Safety risk: Mismatched power delivery can damage cell chemistry or cause the battery to fail unexpectedly during use.
  • Poor runtime: Adapters may reduce output voltage or current, resulting in weak performance.

If you own tools from different Stanley Black & Decker brands, you’ll need to maintain separate battery inventory for each platform. It’s frustrating, but it’s the safe and reliable approach.

What About Stanley FatMax V20 in the UK?

Stanley FatMax V20 is the most relevant SBD platform for UK users. Despite the “V20” branding suggesting 20V, it’s actually an 18V system—marketed confusingly to compete with traditional DeWalt 18V tools. Stanley FatMax V20 batteries are not compatible with DeWalt 18V or 20V tools; they use a completely separate connector.

Stanley FatMax V20 is widely available in UK DIY retailers and is a solid mid-market option for DIYers who don’t already own tools from other systems. It has its own ecosystem of drills, saws, angle grinders, and other compact tools, along with a respectable range of batteries (typically 1.3Ah to 4.0Ah).

If you’re building a cordless kit from scratch in the UK and DeWalt is outside your budget, Stanley FatMax V20 is a viable alternative—just commit to that system rather than trying to mix and match.

DeWalt 20V MAX in the UK

DeWalt 20V MAX is the professional standard in the UK and dominates the market. It has a much wider range of tools, batteries, and chargers than any other Stanley Black & Decker brand. If you’re looking to invest in a cordless system for serious DIY or professional work, DeWalt is the most supported option.

For a detailed breakdown of DeWalt’s ecosystem, battery options, and tool compatibility, see our dedicated DeWalt 20V MAX platform page.


Representative Tools by Brand

Each Stanley Black & Decker brand has its own 18V/20V battery system. Below are representative tools from the brands most relevant to UK buyers. Remember: batteries are NOT interchangeable between these brands despite all being owned by the same parent company.

DeWalt 18V XR — Professional Trade Tools

ToolModel NumberNotes
Combi DrillDCD796NBrushless, 13mm chuck
Combi Drill (Heavy Duty)DCD996NBrushless, 3-speed, 38,250 bpm
Impact DriverDCF887NBrushless, 205 Nm
Impact Driver (Compact)DCF840NBrushless, compact body
Circular SawDCS391N165mm blade, 3,700 rpm
Reciprocating SawDCS367NBrushless, compact
Angle GrinderDCG406NBrushless, 125mm disc
SDS-Plus Rotary HammerDCH273NBrushless, 2.1J impact energy
JigsawDCS334NBrushless, T-shank

DeWalt has 200+ tools on the 18V XR platform — the widest range of any SBD brand. See our DeWalt 20V MAX / 18V XR Battery Compatibility Guide for full details.

Stanley FatMax V20 — Serious DIY & Light Trade

ToolModel NumberNotes
Brushless Combi DrillSFMCD715Brushless, 60 Nm, 13mm chuck
Combi DrillSFMCD711Brushed motor, budget option
Circular SawSFMCS500165mm blade, 4,000 rpm
Reciprocating SawSFMCS300Compact, lightweight
Angle GrinderSFMCG400125mm disc
ChainsawSFMCCS630Brushless, 300mm bar
Hedge TrimmerSFMCHT85555cm blade, 35mm max cut
Multi-ToolSFMCE500Variable speed oscillating

Stanley FatMax V20 is widely available in the UK through Screwfix, Wickes, and Amazon. The range covers around 30 tools across power tools and garden equipment.

Black+Decker 18V — DIY & Garden

ToolModel NumberNotes
Combi DrillBCD700S2-gear, hammer action, 10mm chuck
Drill/DriverBCD00137 Nm torque, 10mm chuck
Impact DriverBDCIM18N155 Nm torque
StrimmerSTC1820PC28cm cut, POWERCONNECT
Hedge TrimmerGTC1845L2045cm blade
ChainsawGKC1825L2025cm bar

Black+Decker focuses on entry-level DIY and garden tools. The range is smaller than DeWalt or Stanley FatMax but covers the essentials for home use.

Craftsman V20 & Porter-Cable 20V MAX — Limited UK Availability

BrandToolModel NumberUK Availability
CraftsmanDrill/DriverCMCD700Import only
CraftsmanBrushless DrillCMCD710Import only
CraftsmanOscillating Multi-ToolCMCE500Amazon (import)
Porter-CableDrill/DriverPCCK607Not officially sold in UK
Porter-CableCombo KitPCCK602L2Not officially sold in UK

Neither Craftsman nor Porter-Cable has official UK distribution. Tools are only available through grey-market importers and US chargers require voltage adapters, making them impractical for UK buyers. We recommend choosing DeWalt, Stanley FatMax, or Black+Decker for UK use.

Where to Buy Stanley Black & Decker Batteries

You can find the full range of Stanley Black & Decker batteries, tools, and chargers on Amazon UK:

Buy DeWalt 20V MAX Batteries on Amazon

Buy Black+Decker 20V Batteries on Amazon

Buy Stanley FatMax V20 on Amazon

Frequently Asked Questions

Can I use DeWalt batteries in Black+Decker tools?

No. DeWalt 20V MAX and Black+Decker 20V MAX batteries have completely different connectors and are not physically compatible. Even if you could force a connection, the battery management systems would not communicate properly, risking damage to both the battery and tool.

Are Stanley FatMax V20 and DeWalt 20V MAX batteries the same?

No. Despite both being marketed as 20V systems, they are entirely separate platforms with different connectors and electronics. Stanley FatMax V20 is actually 18V nominal, not 20V. Do not attempt to use FatMax batteries in DeWalt tools or vice versa.

Can I use a battery adapter between SBD brands?

Adapters exist, but we stronglz advise against using them. They void your warranty, create battery management system incompatibility risks, may reduce power output, and pose a safety hazard. It is better to maintain separate batteries for each system.

Why doesn’t Stanley Black & Decker make one universal battery?

Market segmentation. A universal battery would blur the brand lines between consumer-grade tools (Black&Decker, Stanley) and professional equipment (DeWalt). The company deliberately keeps platforms incompatible to maintain pricing power and brand positioning across its portfolio.

Which SBD brand should I buy in the UK?

DeWalt 20V MAX is the most widely supported in the UK and offers the best tool variety, battery range, and ecosystem. If DeWalt is outside your budget, Stanley FatMax V20 is a solid alternative. Avoid Black+Decker, Craftsman, and Porter-Cable unless you’re already committed to those systems—they have limited UK availability and smaller tool ranges.

Is Stanley FatMax V20 actually 20 volts?

No. Despite the “V20” branding, Stanley FatMax is an 18V system (nominal voltage). It’s marketed with the “V20” name to appeal to customers comparing it against traditional 18V competitors, but the actual voltage is 18V. Don’t be confused by the naming.