Cordless angle grinder

The cordless angle grinder is a portable angle grinder designed to perform straight, cross and angle cuts, or roughing and polishing tasks on various materials such as metal, stone, ceramics and concrete. Unlike corded grinders, this type of angle grinder operates using rechargeable batteries, providing greater freedom of movement and versatility, making it ideal for construction work, light carpentry and DIY . 

Their ergonomic design makes them easy to operate with one hand. Cordless angle grinders have gained popularity due to their portability and ease of use. They are characterized by their mobility, lightness, and versatility, especially in places without access to the electrical grid. They use lithium-ion batteries, usually 12 V, 18 V, or 20 V. 

 History 
The angle grinder was invented in 1954 by the German company Ackermann + Schmitt ( FLEX-Elektrowerkzeuge GmbH ) in Steinheim an der Murr 

 Characteristics 
 It uses a circular abrasive disc that rotates at high speed, with different diameters (usually 115 mm, 125 mm or 150 mm).

 It works with lithium-ion batteries, usually 18 V, 20 V or 36 V.

 Includes auxiliary handle, disc guard and shaft locking system.

 Some models incorporate a brushless motor for greater efficiency.
 Power: between 1200 and 2000 W.
 Disc diameter: 115–150 mm.
 Cutting depth: up to 65 mm at 90°.

 Advantages and disadvantages 
 Advantages 
 Greater freedom of movement than cable ones
 Less weight and size.
 Ideal for quick cuts on site or outdoors.

 Limitations 
 Lower autonomy and power than wired models.
 They require recharging or additional batteries for extended work.

 Battery types 
Cordless angle grinders are rated by battery voltage, which determines their power and runtime.

 10–12 V 
Compact and lightweight models, suitable for precision work or light cutting.

 Bosch GWS 12V-76
 Makita CP100DZ

 14.4 V 
Less common today, but still present in mid-ranges.

 Makita DGA452Z (compatible with 14.4V and 18V batteries)

 18–21 V 
Professional range. High power for demanding jobs.

 Bosch GWS 18V-10
 Makita DGA513Z
 DeWalt DCG405N
 Einhell TE-AG 18 Li
 Worx WX800

 28–36 V 
Industrial models for intensive tasks and larger diameter discs.

 Milwaukee M28 CAG125X
 Makita DGA900Z

 Comparison between market models  
They started with small, low-power radials, but today they cover a very wide range. 
Brand Model Voltage Motor Max RPM Disc diameter Electronic brake Kickback Approx. weight. Observations Bosch GWS 18V-LI 18 V 4 poles 11,000 115 mm No No 2.3 kg Equivalent to 800 W wired Bosch GWS 12V-76 12 V Brushless 19,500 76 mm No No 0.5 kg Ultra compact Bosch GWX 18V-15 PSC 18 V BITURBO 11,000 125 mm Yeah Yeah 2.7 kg X-LOCK, speed control Makita DGA452 18 V With brushes 11,000 115 mm No No 2.3 kg Classic LXT model Makita DGA513Z 18 V Brushless 8,500 125 mm Yeah Yeah 2.5 kg Cruise control, AVT Makita DGA900Z 36 V Brushless 7,800 230 mm Yeah Yeah 5.4 kg Double battery, industrial use DeWalt DCG405N 18 V Brushless 9,000 125 mm Yeah Yeah 1.74 kg XR, compact and powerful DeWalt DCG418 54 V Brushless 9,000 125 mm Yeah Yeah 2.2 kg FLEXVOLT, high performance Einhell TE-AG 18/115 Li 18 V With brushes 8,500 115 mm No No 1.2 kg Light, economical Einhell AXXIO 18/125 18 V Brushless 8,500 125 mm No Yeah 1.4 kg Professional, PurePower engine Worx WX800 20 V Brushless 8,600 115 mm Yeah Yeah 1.9 kg Compact, PowerShare Worx WX812L 20 V Brushless 8,500 115 mm Yeah Yeah 1.8 kg Nitro, anti-kickback
Brand Model Voltage Disc diameter Max cut at 90° Makita HS301DSAE 12 V 85 mm 25 mm Bosch GKS 18V-57 18 V 165 mm 57 mm DeWalt DCS570N 18 V 184 mm 64 mm Metabo KS 18 LTX 66 BL 18 V 165 mm 66 mm

 Technical notes 
 Max RPM : No-load speed. The higher the speed, the more efficient it is at fine cutting.
 Electronic brake : Stops the disc when the trigger is released, improving safety.
 Kickback control : Detects blockages and shuts off the tool to prevent kickback.
 BITURBO / FLEXVOLT / XGT : Technologies that increase performance in high-end models.

 Disc table for cordless grinders (76–125 mm) 
Diameter (mm) Usual compatibility Available disc types Common applications 76 mm Compact mini grinders Fine cut, multi-material, metal Light repairs, automotive 85 mm Bosch GWS 12V, Makita 12V Cutting metal, ceramic, diamond Electrical installations, plumbing 100 mm Some 12–14.4 V Cutting, roughing, turbo diamond Ceramic cutting, DIY 115 mm Standard in 18 V All types: cutting, roughing, diamond, flap Construction, renovations, carpentry 125 mm Standard in 18–21 V All types + special discs (brush, polishing) Professional work, metallurgy, masonry

 Battery pack technology 
Battery packs require battery balancing, which is a technique that maximizes a battery's ability to have all of its energy available for use and increases battery longevity.  Typically, a battery regulator is a device built into the battery pack that performs battery balancing.  Most modern cordless drills use lithium-ion batteries which offer: 

 Higher energy density.
 Less weight.
 Absence of memory effect.
 Fast charging and long life.

Manufacturer Model Voltage Capacity (Ah) BMS type Observations Bosch PBA 12V 2.5Ah 12V 2.5 External Home use, Power for All system Bosch GBA 18V 5.0Ah 18V 5.0 Internal Professional, CoolPack technology Bosch ProCORE 18V 8.0Ah 18V 8.0 Internal High energy density, smart BMS Makita BL1021B 12V 2.0 External CXT Series, Compact Makita BL1850B 18V 5.0 Internal LXT Series, with charge indicator Makita BL4040 40V 4.0 Internal XGT Series, Battery-Machine Digital Communication DeWalt DCB124 12V 3.0 External XR Compact, light professional use DeWalt DCB184 18V 5.0 Internal XR Li-Ion, compatible with the entire 18V range DeWalt DCB546 18V / 54V 6.0 Internal FLEXVOLT, dual voltage, smart BMS

 Internal architecture of battery packs 
The nominal voltage of a battery pack is determined by the number of 3.7 V cell subgroups connected in series. Each subgroup can be made up of one or more cells in parallel, which increases the capacity (Ah) of the pack. 
+Structural typology according to voltage Nominal voltage Number of 3.7V subgroups in series Example of models BMS Comment 3.7 V 1 USB Power Banks Not required The cells are in parallel; a 3.7 V → 5 V DC-DC converter is used. 10.8–12 V 3 Black&Decker BL1510, Makita BL1013, Bosch BAT411 (PS31) External 2 intermediate sockets for BMS on the charger 14,4–16 V 4 Makita BL1415G External 3 intermediate sockets; BMS normally in the charger 18–21 V 5 Makita BL1850B, Bosch SM31 (GSR 1800-LI) Internal 4 intermediate sockets; with integrated BMS
The presence of intermediate taps in the pack's wiring allows the BMS (internal or located in the charger) to monitor and balance the state of charge of each group of cells. This balancing is essential in series configurations, since the cells do not balance themselves automatically as they do in parallel. Some low-cost designs use diodes to limit cell imbalance, although this technique offers limited protection and may reduce the battery's lifespan. 

 Power packs => % Charge vs. Volt 
% load 3.7 V pack 10.1 V pack 14.8 V pack 18 V pack 21 V pack 100% 4.2 V 12.6 V 16.8 V 21.0 V 25.2 V 75% 3.9 V 11.7 V 15.6 V 19.5 V 23.1 V 50% 3.7 V 10.8 V 14.4 V 18.0 V 21.0 V 25% 3.5 V 10.0 V 13.2 V 16.5 V 18.9 V

 Applications 
 Cutting of wooden boards, MDF, plywood.
 Cutting metal profiles with suitable discs.
 Cutting of plastics and synthetic materials.
 Installation, assembly and renovation work.

 Security 
Hand-held radial saws include protection systems such as:

 Adjustable disc guard.
 Safety switch.
 Non-slip grip.
 Cutting guides and cutting line blowers.

 Related pages 
 Angle grinder

 References 

 Literature 



 Other websites 



Category:Construction
Category:Tools