M18 Brushless 1/4" Hex 3 Speed Impact Driver Bare Tool

Battery answer

Every reviewed M18 pack powers SKU 2851-20 at full rated performance, with no battery-specific condition.

Battery platform
Milwaukee M18
Packs required
Not published by Milwaukee
Battery requirement sources (1)

Milwaukee · Impact Drivers · SKU 2851-20 · Milwaukee source

Compare the reviewed M18 packs

BatteryCapacityEnergy Power levelAnswer
48-11-1813 12 Ah 216 Wh PWR5 Works
48-11-1820 2 Ah 36 Wh not published Works
48-11-1828 3 Ah 54 Wh not published Works
48-11-1840 4 Ah 72 Wh not published Works
48-11-1850 5 Ah 90 Wh PWR2 Works
48-11-1850R 5 Ah 90 Wh not published Works
48-11-1861 6 Ah 108 Wh PWR4 Works
48-11-1865 6 Ah 108 Wh PWR3 Works
48-11-1881 8 Ah 144 Wh PWR4 Works

Energy is capacity × nominal voltage — our arithmetic on Milwaukee’s figures, not a number they publish. It is the only honest way to compare packs across capacities. Power level is Milwaukee’s own PWR tier where they publish one.

Compatibility sources (1)
  • Milwaukee Toolmanufacturer support, retrieved 2026-07-30
    “All M18 Batteries are compatible with M18 tools & chargers.”

Tool specifications and manufacturer claims

Basic tool facts

BrushlessYes
Weight, bare tool Not published for this exact SKU
Specification sources (1)

Full specifications

As published by Milwaukee for SKU 2851-20, read 2026-07-31. Values are quoted in their units, not reformatted.

Chuck Size1/4" Hex
Chuck TypeHex Quick Change
Power SourceCordless
Motor TypeBrushless
Length5.1"
Weight2 lbs
Height7.75 in
Width2.25"
RPM0-1700/0-2600/0-3400
IPM0-1500/0-3400/0-4200
Torque1600 in-lbs
LEDYes
Voltage18V
BrushlessYes
Maximum RPM3,400
RPM Range0 - 3,400

What Milwaukee says about it

Manufacturer marketing copy, reproduced so you can judge it. We have not tested these claims.