Best Electric Grease Gun: 5 Cordless Grease Guns Compared

Compare the picks

Specifications are manufacturer rated, as published on each listing and collected 9 October 2026. Where a listing contradicts itself, both figures are shown.

How we scored them

Each cordless grease gun is scored on performance, build, value, safety and warranty, with the weights published on our How We Pick page. None states a UL, ETL or CSA listing, so all score zero on safety, while most provide a manufacturer warranty term.

Scores run from 9.2 to 9.8: each product’s point total is placed on that range, so more points always means a higher score.

What the listings tell you

Across the grease gun listings, most state an operating pressure rating between 10,000 and 12,000 PSI, while one omits pressure entirely. Several listings state a grease delivery rate, ranging from 5.0 to 5.3 oz/min. Multiple listings specify hose lengths of 42 or 48 inches. Most listings provide a manufacturer warranty of 3 or 5 years, while one provides no warranty terms. Clerical contradictions appear in multiple listings, including incorrect component labels and conflicting voltage ratings.

Buying guide: choosing the best electric grease gun

Operating pressure and flow rate

Grease guns require adequate pressure to unseat stuck check balls and push fresh grease through clogged fittings. Listings with 10,000 or 12,000 PSI ratings provide substantial force for heavy machinery. Flow rates between 5.0 and 5.3 oz/min deliver lubricant quickly, while variable speed triggers allow finer control on sensitive bearing seals.

A variable speed trigger lets you feather the motor speed to dispense tiny dabs of lubricant into sealed ball bearings where excessive pressure could rupture dust boots. In contrast, a two-speed gearbox allows switching mechanically between high pressure for clearing obstinate grease passages and high flow for filling large commercial cavities.

Hose length and access

Grease fittings on suspension components, drive shafts and agricultural equipment are frequently located in recessed spaces. A 42-inch or 48-inch flexible hose lets you position the tool body on the ground or a flat surface while reaching awkward grease zerks. For tight, compact jobs where a long hose is cumbersome, a small grease gun offers an alternative.

Coupler mechanisms and hydraulic locking

High operating pressures create hydraulic lock when grease cannot pass through a frozen fitting. When backpressure builds to 10,000 or 12,000 PSI, the coupler jaws clamp tightly against the fitting nipple, making removal difficult. Quick-release couplers equipped with thumb levers release pressure mechanically, allowing immediate disengagement. If using a conventional threaded coupler, slightly unthreading the coupler barrel relieves internal hydraulic tension so the tool pulls free without snapping the zerk. Do not yank the hose, as pulling can fracture the zerk or tear the crimped hose fitting. Relieve line pressure by depressing the air-bleeder valve or carefully unthreading the coupler sleeve slightly until grease seeps out and the clamping jaws relax.

Cartridge loading and bulk grease

Most cordless models accept standard 14 oz grease cartridges, while select units also accommodate bulk loading up to 400cc. Cartridge loading minimizes mess during maintenance, whereas bulk loading allows filling from larger shop containers. Look for an air-bleeder valve to purge air pockets and restore grease flow after refilling.

Purging air and restoring prime

Loss of prime occurs when air enters the pump cavity instead of solid lubricant. Common causes include empty cartridges, air pockets trapped during bulk filling, or a follower plate stuck inside the barrel. If the motor hums but no lubricant emerges, unlatch the follower rod to verify spring pressure against the grease column, then depress the air-bleeder valve on the pump head until solid grease escapes.

Protecting bearing seals against high pressure

Battery-powered grease guns generate substantial hydraulic force, up to 10,000 or 12,000 PSI, which far exceeds the retaining strength of rubber lip seals. Over-lubricating electric motors or sealed wheel hubs can rupture dust boots and push grease past internal seals into motor windings or brake assemblies. Operators should monitor grease displacement carefully, using variable triggers or stroke counters to avoid overfilling.

Preventing contamination with filter screens

Abrasive grit is the primary cause of internal pump wear and check valve failure. Because grease is inherently sticky, airborne debris and metal shavings readily cling to cartridge openings and loader nipples. Listings that include integrated pump filter screens prevent foreign particles from entering the pumping cylinder. Always wipe fitting caps clean before attaching the hose, and keep cartridge barrels free of debris during changes.

Battery platform and runtime

Cordless grease guns operate on lithium-ion batteries such as 18V or 20V systems. If you already own compatible batteries from brands like Milwaukee or DeWalt, buying a bare tool saves money. For standalone purchases, complete kits provide batteries, chargers and carrying cases. Listings state runtimes capable of dispensing up to 16 cartridges per battery charge.

Grease gun maintenance

Keep grease fittings clean before attaching couplers to prevent dirt from entering bearing assemblies. Built-in pump filter screens help block debris from entering the pump mechanism. Wipe down hoses and store the tool in a case to protect hoses from kinks. For other shop tasks, explore our cordless tools category.

Frequently Asked Questions

How do electric grease guns work?

An electric grease gun uses a battery-powered motor to drive an internal piston pump. The pump draws lubricant from a grease cartridge or bulk reservoir and forces it through a flexible hose under high pressure, dispensing grease at the pull of a trigger without manual pumping.

What is the best electric grease gun for home garages?

The best model depends on whether you already own power tool batteries. If you use Milwaukee M18 batteries, a bare tool with a 2-speed drive and grease counter provides precise flow. If you use DeWalt 20V batteries, a high-volume model with a variable speed trigger matches your platform. Complete kits with included batteries suit buyers without existing tool systems.

How do you load an electric grease gun?

Unscrew the grease barrel from the pump head and retract the follower rod until it locks. Insert a standard 14 oz grease cartridge with the open end facing forward, remove the pull-tab seal, thread the barrel back onto the pump head, and release the follower rod. For bulk filling, draw grease into the barrel or connect a filler pump to the bulkhead fitting.

How do you prime an electric grease gun after changing cartridges?

Air pockets trapped during cartridge changes can stop grease from flowing. Depress the air-bleeder valve on the pump head while running the motor or priming the pump until grease emerges free of air bubbles. Once grease flows consistently from the coupler, release the valve.

How much pressure does an electric grease gun need?

Most automotive and agricultural maintenance requires sufficient force to overcome hardened grease and spring-loaded ball checks. Models delivering 10,000 to 12,000 PSI provide enough force to clear blocked fittings that manual grease guns struggle to service.

Related: our cordless tools hub, the best small grease gun, the best cordless ratchet wrench and our best cordless impact wrench for lug nuts.