The Milwaukee 2845-20 M18 CARRY-ON 3600W/1800W Power Supply is a battery-powered temporary jobsite power source for contractors who need outlet-style power without the noise, fumes, and maintenance of a gas generator. This is a portable power supply designed for running one 15 amp jobsite tool or charging electronics where corded power is not practical. Model Number: 2845-20. If you work in finished spaces, indoors, underground, or anywhere extension cords turn into a hassle, this unit solves a very real problem.

The numbers are what matter here. You get 3600 starting watts and 1800 running watts of pure sine wave inverter power. In plain terms, that means the unit is built to start and run one demanding 15 amp tool, not just lights and chargers. Milwaukee specifically positions it for tools like table saws, pancake compressors, and pipe threaders. Instant start technology helps it get those tools moving cleanly, while the sustained output is meant to keep them running without the usual compromises you get from lighter-duty battery power stations.

One of the biggest advantages of this Milwaukee portable power supply is how it fits into an existing M18 setup. It works with all M18 batteries, so if your truck is already stocked with M18 packs, you are not buying into another battery platform just to get temporary power. Milwaukee also states that the unit runs on four batteries, which tells you right away this is not a casual backup brick. It is built to pull serious power from multiple packs to support real work.

Milwaukee also got the jobsite practicality right. The unit is quiet, rated at 66 dB(A), and it is emissions-free, which is a major deal for indoor remodels, service work in occupied spaces, underground work, confined spaces, scissor lifts, and utility carts. Those are exactly the places where gas units are a pain or simply not allowed. At 28 lbs without batteries, it is not featherweight, but it is compact enough to move where you need it, and the optional shoulder strap compatibility makes that easier when you are carrying it in and out of the site.

The design is also more useful than a basic inverter box. Along with outlet power, you get USB-C PD and USB-A ports for faster charging of phones and other sensitive electronics. Milwaukee also includes an integrated 3A standard simultaneous M18 charger when the unit is not in discharge mode, which helps cut down on the amount of extra charging gear you need to bring. There are also lockable battery bays for padlock use, a smart feature for crews leaving tools and batteries in shared work areas.

From a build and form-factor standpoint, this is clearly engineered as a jobsite piece, not a camping accessory trying to pass as contractor gear. The protective outer frame, compact footprint, and carry-focused layout are meant to live around materials, cords, and rough floors. Its listed dimensions of 15.05 inches long, 12.25 inches wide, and 13.75 inches high make it small enough to stage near the cut station or next to the work area instead of parking it far away like a generator.

Who should buy it? The Milwaukee 2845-20 M18 CARRY-ON 3600W/1800W Power Supply makes the most sense for remodelers, service contractors, finish crews, punch-list work, commercial interior crews, and anyone already invested in M18 batteries who needs portable 120V-style power without the normal generator headaches. If you need to run one serious corded tool in places where noise, exhaust, or access are an issue, this is the kind of power solution that earns its keep fast.

Generator alternative for crews already deep in M18

The Milwaukee 2845-20 M18 CARRY-ON 3600W/1800W Power Supply is one of the smarter jobsite power options out there if your goal is real tool power without gas-generator baggage.

• Who it's for: Contractors and service crews who already own M18 batteries and need portable power for one corded 15 amp tool, especially indoors or in finished spaces.
• Why it stands out: It is built around a real contractor use case, not just backup charging. Pure sine wave output, one-tool 15 amp capacity, quiet operation, and M18 battery compatibility make it legitimately useful on site.
• Worth knowing: This is not meant to replace a big generator for running multiple tools at once. It is best when you need clean, portable power right where the work is happening.

• What kind of product is this? This is a portable power supply designed to provide temporary outlet-style power for one 15 amp tool and for charging electronics on the jobsite.
• What batteries does it use? It fits all Milwaukee M18 batteries and operates using any four M18 battery packs.
• Can it be used indoors? Yes. Milwaukee describes it as quiet and emissions-free, making it suitable for indoor, underground, and confined-space use.
• Is it safe for sensitive electronics? Yes. It uses a pure sine wave inverter and also includes USB-C PD and USB-A ports for charging electronics.
• Does it charge M18 batteries too? Yes. It has an integrated 3A standard simultaneous M18 charger when the unit is not in discharge mode.