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:

 

Brand Latform Name Nominal Voltage Connector Type UK Availability Market Segment
DeWalt 20V MAX / FLEXVOLT 20V (18V nominal) 5-slot rectangular Widely available Professional / serious DIY
Black+Decker 20V MAX / POWERCONNECT 20V (18V nominal) 4-slot connector Limited availability Consumer / casual DIY
Stanley FatMax V20 System 18V (despite “V20” name) Proprietary connector UK-focused brand Enthusiast / semi-professional
Craftsman V20 System 20V (18V nominal) 5-slot (reversed polarity) Noth America primarily Consumer / DIY
Porter-Cable 20V MAX 20V (18V nominal) Unique connector Virtually unavailable in UK Consumer

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

Tool Model Number Notes
Combi Drill DCD796N Brushless, 13mm chuck
Combi Drill (Heavy Duty) DCD996N Brushless, 3-speed, 38,250 bpm
Impact Driver DCF887N Brushless, 205 Nm
Impact Driver (Compact) DCF840N Brushless, compact body
Circular Saw DCS391N 165mm blade, 3,700 rpm
Reciprocating Saw DCS367N Brushless, compact
Angle Grinder DCG406N Brushless, 125mm disc
SDS-Plus Rotary Hammer DCH273N Brushless, 2.1J impact energy
Jigsaw DCS334N Brushless, 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

Tool Model Number Notes
Brushless Combi Drill SFMCD715 Brushless, 60 Nm, 13mm chuck
Combi Drill SFMCD711 Brushed motor, budget option
Circular Saw SFMCS500 165mm blade, 4,000 rpm
Reciprocating Saw SFMCS300 Compact, lightweight
Angle Grinder SFMCG400 125mm disc
Chainsaw SFMCCS630 Brushless, 300mm bar
Hedge Trimmer SFMCHT855 55cm blade, 35mm max cut
Multi-Tool SFMCE500 Variable 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

Tool Model Number Notes
Combi Drill BCD700S 2-gear, hammer action, 10mm chuck
Drill/Driver BCD001 37 Nm torque, 10mm chuck
Impact Driver BDCIM18N 155 Nm torque
Strimmer STC1820PC 28cm cut, POWERCONNECT
Hedge Trimmer GTC1845L20 45cm blade
Chainsaw GKC1825L20 25cm 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

Brand Tool Model Number UK Availability
Craftsman Drill/Driver CMCD700 Import only
Craftsman Brushless Drill CMCD710 Import only
Craftsman Oscillating Multi-Tool CMCE500 Amazon (import)
Porter-Cable Drill/Driver PCCK607 Not officially sold in UK
Porter-Cable Combo Kit PCCK602L2 Not 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.