The Cordless Alliance System (CAS) is the world’s only true cross-brand battery alliance for cordless power tools. Founded in 2018 by Metabo and now backed by 45+ manufacturers across Europe, CAS allows any battery from any member brand to work in any member brand’s tools. Unlike regional platforms like Makita’s LXT or DeWalt’s 20V MAX, CAS is genuinely platform-agnostic: a battery made by Metabo works identically in tools from Rothenberger, Mafell, Steinel, and every other member. With over 450 compatible tools across drills, impact drivers, saws, grinders, and specialist equipment, CAS represents a fundamental shift in how power tool ecosystems work.
The system is particularly significant for professional tradespeople and specialist contractors who use tools from multiple brands — plumbers using Rothenberger drills and Metabo grinders, for example, can now standardise on a single battery type rather than carrying separate batteries for each brand. However, CAS remains largely unknown in the consumer DIY market and is primarily distributed through specialist trade suppliers rather than high street retailers.
This guide covers every CAS member brand, all compatible battery models, charger compatibility, UK availability, and clarifies common misconceptions (particularly the widespread confusion between CAS and other third-party battery systems).
How CAS Works
The Cordless Alliance System operates on a simple principle: standardised connector, standardised voltage, standardised safety protocols. Every CAS battery uses an 18V Li-Ion cell pack with a proprietary Metabo-designed connector that is identical across all member brands. This means a Metabo battery works in a Rothenberger tool, a Steinel battery works in a Mafell tool, and so on, with zero adaptation required.
CAS batteries use tabless Li-Ion cells — a design that improves cooling, extends cycle life, and increases power delivery compared to conventional tabbed cells. Most CAS batteries include integrated battery management systems (BMS) that communicate with compatible tools to optimise performance and protect against overcharge, over-discharge, and temperature faults.
Each CAS member manufactures their own batteries and chargers but must comply with the CAS specification for voltage (18V nominal, 20V peak), connector design, and safety protocols. This means you are not locked into a single manufacturer’s charger — a Metabo charger will charge a Rothenberger battery, though some newer batteries include fast-charge protocols specific to certain charger models.
TL;DR Compatibility Rules
- Any CAS battery works in any CAS tool, regardless of brand.
- All CAS systems use 18V nominal (20V peak) voltage.
- CAS batteries are only 18V — there is no 20V, 40V, or variable-voltage CAS line.
- CAS member brands are typically specialist or professional-focused (not consumer DIY brands).
- A CAS battery will not work in a Makita, DeWalt, Milwaukee, or Ryobi tool (these are separate, proprietary systems).
- A Makita, DeWalt, Milwaukee, or Ryobi battery will not work in a CAS tool.
- CAS batteries are available primarily through specialist trade suppliers and online retailers, not consumer DIY channels.
- Chargers vary by brand and model; cross-brand charging is possible but not guaranteed on all combinations.
CAS Member Brands
The following table lists all known Cordless Alliance System members, their primary specialisation, and UK availability status:
| Brand | Primary Specialisation | UK Availability | Typical Tools |
|---|---|---|---|
| Metabo | General-purpose power tools | Yes — Online & trade suppliers | Drills, impact drivers, grinders, saws, sanders |
| Rothenberger | Plumbing & HVAC specialist tools | Yes — HVAC & plumbing suppliers | Pipe threading, cutting, pressing tools, drain cleaners |
| Mafell | Fine woodworking & joinery | Limited — Specialist woodworking suppliers | Precision circular saws, track saws, joinery drills |
| Steinel | Heat guns & adhesive application | Yes — Tool retailers & online | Heat guns, glue applicators, shrink-wrap tools |
| Eibenstock | Concrete mixing & drilling | Limited — Specialist building suppliers | Paddle mixers, core drills, floor tools |
| Haaga | Sweepers & floor cleaning | Rare — German import specialists | Cordless sweepers, floor polishers |
| Starmix | Industrial vacuum systems | Limited — Specialist vacuum suppliers | Wet & dry vacuums, extraction equipment |
| Collomix | Industrial mixing equipment | Rare — Specialist trade distributors | Heavy-duty paddle mixers, grout mixers |
| Scangrip | Work lighting & inspection | Yes — Tool retailers & online | LED work lights, inspection lamps |
| Rubi | Tiling & masonry specialist | Limited — Specialist tiling suppliers | Tile saws, grout saws, masonry tools |
This list represents the core confirmed CAS members. Additional manufacturers may have joined the alliance since these specifications were published; check the official CAS partnership list for the most current member roster.
Representative Tools by Member Brand
With over 450 tools across 45+ brands, the CAS system covers far more specialist categories than any single-brand platform. Below are representative tools from the key CAS member brands available in the UK.
Metabo — Power Tools
Metabo is the founding brand and largest member of the CAS alliance, offering the widest range of general-purpose cordless tools.
| Tool | Model Number | Notes |
|---|---|---|
| Cordless Drill/Driver | BS 18 LT BL Q | Brushless, 75 Nm, Quick system |
| Cordless Impact Driver | SSD 18 LTX 200 BL | Brushless, 200 Nm |
| Cordless Impact Wrench | SSW 18 LTX 400 BL | Brushless, 400 Nm, compact |
| Cordless Angle Grinder 125mm | W 18 L 9-125 Quick | Brushless, 10,000 RPM |
| Cordless Circular Saw | KS 18 LTX 57 | 165mm blade, 57mm depth of cut |
| Cordless Reciprocating Saw | SSE 18 LTX BL Compact | Brushless, variable speed |
| Cordless Multi-Tool | MT 18 LTX BL QSL | Brushless, StarlockPlus |
| Cordless Jigsaw | STA 18 LTX 100 | Brushless, 100mm cut depth |
| Cordless Vacuum | AS 18 HEPA PC Compact | HEPA filter, wet/dry |
| Cordless SDS-Plus Hammer | KHA 18 LTX BL 24 Quick | Brushless, 2.2 J, 3-mode |
Mafell — Precision Woodworking
Mafell brings premium German precision woodworking tools to the CAS system — tools not available from any other battery platform.
| Tool | Model Number | Notes |
|---|---|---|
| Cordless Plunge Saw | MT 55 18M bl | Brushless, 57mm depth, guide rail compatible |
| Cordless Cross-Cut Saw | KSS 40 18M bl | Brushless, 40mm depth |
| Cordless Jigsaw | P1 cc 18M bl | Brushless, precision cut |
Rothenberger — Plumbing & Press Tools
Rothenberger offers professional pipe pressing and plumbing tools — a category unique to the CAS ecosystem.
| Tool | Model Number | Notes |
|---|---|---|
| Electro-Hydraulic Press | ROMAX 4000 | 32 kN, 12–108mm, Bluetooth |
| Compact Press Tool | ROMAX Compact III | 24 kN, 12–35mm, lightweight |
| Cordless Pipe Cutter | ROCUT 110 | Plastic pipe, 40–110mm |
Steinel — Heat Guns
Steinel manufactures professional cordless heat guns — the only brand offering this tool type on CAS.
| Tool | Model Number | Notes |
|---|---|---|
| Cordless Heat Gun (Standard) | MobileHeat 3 (MH3) | 600W, 570–930°F, 30s heat-up |
| Cordless Heat Gun (Premium) | MobileHeat 5 (MH5) | 1,000W, LCD display, 4s heat-up |
| Cordless Heat Gun (High-Temp) | MobileHeat 7 (MH7) | 1,022°F max, TPO/PVC welding |
Starmix — Vacuum & Dust Extraction
Starmix is a specialist vacuum and dust extraction brand, offering professional-grade cordless cleaning solutions.
| Tool | Model Number | Notes |
|---|---|---|
| Cordless Wet/Dry Vacuum | ISC BATRIX M 36-18V | Dual-voltage, M-class filter |
| Cordless Dust Extractor (L-Class) | iPulse L-1635 | L-class, 35L capacity |
| Cordless Dust Extractor (M-Class) | iPulse M-1635 | M-class, construction dust |
| Cordless Dust Extractor (H-Class) | iPulse H-1635 | H-class, hazardous dust |
Collomix — Mixing & Stirring
Collomix makes professional-grade cordless mixing equipment for construction sites.
| Tool | Model Number | Notes |
|---|---|---|
| Cordless Paddle Mixer | XO 20 NC | 2-speed, up to 40L, HEXAFIX coupling |
This is a representative selection. The full CAS system includes tools from over 45 brands covering categories such as sweeping (Haaga), metal finishing (Eisenblätter), plaster processing (Eibenstock), tile cutting (Rubi), and lighting (Scangrip). All use the same 18V CAS/Metabo battery.
CAS Battery Models
The two primary CAS battery lines are Metabo Li-Power (standard duty) and Metabo LiHD (high demand). Both series are compatible across all CAS member brands. Other CAS members produce batteries under their own brand names but to identical CAS specifications.
| Battery Series | Capacity | Technology | Weight (approx.) | Best For | Buy |
|---|---|---|---|---|---|
| Li-Power 2.0 | 2.0 Ah | Standard Li-Ion | 330 g | Light duty, reduced weight | View on Amazon |
| Li-Power 4.0 | 4.0 Ah | Standard Li-Ion | 590 g | General purpose, balanced runtime | View on Amazon |
| Li-Power 5.2 | 5.2 Ah | Standard Li-Ion | 710 g | Extended runtime, trade use | View on Amazon |
| LiHD 4.0 | 4.0 Ah | Tabless Li-Ion (high demand) | 570 g | High power tools, faster charging | View on Amazon |
| LiHD 5.5 | 5.5 Ah | Tabless Li-Ion (high demand) | 625 g | Professional daily use | View on Amazon |
| LiHD 7.0 | 7.0 Ah | Tabless Li-Ion (high demand) | 775 g | Heavy-duty drills, grinding, all-day runtime | View on Amazon |
| LiHD 8.0 | 8.0 Ah | Tabless Li-Ion (high demand) | 880 g | Extended professional projects | View on Amazon |
| LiHD 10.0 | 10.0 Ah | Tabless Li-Ion (high demand) | 1080 g | Extended-runtime production work | View on Amazon |
Other CAS member brands (Rothenberger, Steinel, Mafell, etc.) produce batteries to the same 18V CAS specification. These may be branded under their own names but are mechanically and electrically identical to the Metabo equivalents, making them fully interchangeable.
CAS Charger Compatibility
CAS uses a standard 18V charging protocol, meaning most CAS chargers can charge any CAS battery. However, specific fast-charge protocols vary by manufacturer. The following Metabo chargers are widely used within the CAS ecosystem:
- ASC 55 — Compact single-slot charger. Standard charge time ~30–45 minutes for 4.0 Ah battery.
- ASC 145 — Dual-slot charger with faster charging. ~20–30 minutes for 4.0 Ah.
- ASC Ultra — Professional dual-slot charger with temperature management. ~15–20 minutes for 4.0 Ah.
Rothenberger, Steinel, and other CAS members produce their own chargers which, whilst branded differently, operate on the same charging standard. A Metabo battery will charge in a Rothenberger charger and vice versa, though the exact charge time may vary slightly depending on charger design and battery model.
UK Availability
CAS tools and batteries are not widely stocked in mainstream UK DIY retailers (B&Q, Screwfix, Toolstation). Instead, they are distributed through specialist trade suppliers:
- Metabo — Available through online retailers and select trade suppliers. Specialist stockists include European power tool specialists.
- Rothenberger — Plumbing and HVAC specialists, particularly those supplying contractors. Online distribution through trade distributors.
- Steinel — More readily available; heat guns stocked by some tool retailers and specialist suppliers. Check online retailers for CAS-compatible models.
- Mafell, Eibenstock, Haaga, Starmix, Collomix, Scangrip, Rubi — Imported on demand through specialist distributors. Limited to specialist suppliers in respective trades (woodworking, tiling, plumbing, etc.).
For most UK users, online European retailers and Amazon.co.uk are the primary sources. Pricing is often higher than equivalent Makita or DeWalt tools due to smaller UK distribution networks.
What CAS is NOT
The Cordless Alliance System is frequently confused with other battery alliances and third-party systems. It is important to understand these distinctions:
CAS is NOT Einhell Power X-Change
Power X-Change (also 18V) is Einhell’s proprietary ecosystem used by Einhell and a small number of other manufacturers. It is NOT part of the Cordless Alliance System. Power X-Change batteries will not work in CAS tools, and CAS batteries will not work in Power X-Change tools. This is a common point of confusion — both systems are 18V European systems, but they use different connectors and are completely incompatible.
CAS is NOT Compatible with Makita, DeWalt, Milwaukee, or Ryobi
CAS is a completely separate ecosystem from the major consumer brands. A CAS battery will not fit in a Makita LXT, DeWalt 20V MAX, Milwaukee M18, or Ryobi ONE+ tool, regardless of voltage. These are proprietary systems with proprietary connectors:
- Makita LXT — Uses Makita’s proprietary connector. 18V nominal.
- DeWalt 20V MAX — Uses DeWalt’s proprietary connector. 20V nominal.
- Milwaukee M18 — Uses Milwaukee’s proprietary connector. 18V nominal.
- Ryobi ONE+ — Uses Ryobi’s proprietary connector. 18V nominal.
Whilst all of these systems are 18V (or approximately 18V), the physical connector shape is different on each system, making cross-system compatibility impossible without an adapter.
CAS Tools Must Be Explicitly CAS-Compatible
Not all Metabo or Rothenberger tools are CAS-compatible. Some older models and certain product lines use proprietary battery designs. Before purchasing a tool, always verify that it is explicitly marketed as “CAS compatible” or “Cordless Alliance System compatible.” Check the product manual or contact the manufacturer if in doubt.
Frequently Asked Questions
Can I use a Metabo battery in a Rothenberger tool?
Yes. Any CAS battery from any member brand will work identically in any CAS tool from any other member brand. A Metabo LiHD 5.5 Ah battery will power a Rothenberger pipe threader with no modifications or adapters required. The battery will deliver the same voltage and capacity regardless of which brand manufactures the tool.
Is Einhell part of the Cordless Alliance System?
No. Einhell manufactures Power X-Change, a separate and incompatible 18V ecosystem. Despite both systems being 18V, they use different connectors and cannot be mixed. If you own Einhell Power X-Change tools, you must use Power X-Change batteries — CAS batteries will not fit.
How many tools are in the CAS system?
CAS currently includes over 450 compatible tools across 10+ member brands. This includes drills, impact drivers, circular saws, angle grinders, reciprocating saws, heat guns, vacuum systems, sweepers, paddle mixers, pipe threading tools, and specialist equipment. The system continues to expand as new manufacturers join the alliance.
Are CAS batteries compatible with Makita or DeWalt?
No. CAS batteries will not work in Makita LXT, Makita XGT, DeWalt 20V MAX, DeWalt FLEXVOLT, Milwaukee M18, or any other non-CAS system. These systems use proprietary connectors that are physically incompatible with CAS. You cannot use an adapter to make them work — the connector shape, voltage regulation, and safety protocols are entirely different.
Where can I buy CAS batteries in the UK?
CAS batteries are available through online retailers, specialist trade suppliers, and European power tool distributors. Metabo batteries are most readily available through online channels. Rothenberger batteries are best found through plumbing and HVAC specialist distributors. Steinel heat guns with CAS batteries are available through selected tool retailers. For other brands (Mafell, Eibenstock, etc.), contact specialist suppliers in those trades or import from European distributors.
What is the difference between Li-Power and LiHD CAS batteries?
Li-Power batteries use standard tabbed Li-Ion cells and are suitable for general-purpose, light-to-medium duty work. LiHD batteries use tabless Li-Ion cells that are designed for higher power demand, faster charging, and longer cycle life. LiHD batteries offer better performance and durability for professional, full-time use but cost more. For occasional use, Li-Power is sufficient; for daily trade use, LiHD is recommended. Both are fully compatible across all CAS tools and chargers.