The Milwaukee M18 TOP-OFF 175W Power Supply, Model 2846-20, is a compact battery-powered inverter that lets you run or recharge small electronics from any compatible Milwaukee M18 battery. This is a power supply designed for powering and charging small devices on the jobsite, in the truck, or anywhere you do not have easy access to a wall outlet. If you already run M18 tools, this gives that same battery platform another job beyond drills, impacts, and lights.

What makes this unit useful is the output setup. You get 175 watts of continuous power along with one 120V AC outlet, one USB-C Power Delivery 45W port, and one USB-A 2.4A port. In plain terms, that means you can charge or power up to three devices at once, including phones, tablets, laptops, lights, and other small electronics. Milwaukee specifically positions it for personal devices and small electronics, not for high-draw tools or heating appliances, which is the right way to look at it.

The USB-C Power Delivery port matters here because it is not just an afterthought. At 45 watts, it is built to charge newer devices faster than basic low-output wall chargers. For anyone using a laptop, tablet, or phone as part of a mobile workstation, that is the difference between keeping the device alive and actually getting meaningful charge back during the workday.

Milwaukee kept the form factor small and light at 0.8 lb, with overall dimensions of 3.78 inches long, 3.3 inches wide, and 3.33 inches high. That compact size is a big part of the appeal. It does not take up much room in a bag, gang box, or truck compartment, and it is easy to keep around as a problem-solver when you need quick portable power for diagnostics, communication, lighting, or charging.

For real jobsite use, the built-in metal rafter hook is one of those simple features that earns its keep. Milwaukee designed it so you can hang the unit from common materials or carts when worksurface space is limited. That keeps your power source off the floor, closer to eye level, and easier to manage around cords, tools, and materials. It is a small detail, but it makes the unit more practical in unfinished spaces, service calls, and temporary work areas.

From a system standpoint, the biggest advantage is straightforward compatibility. The unit fits all Milwaukee M18 batteries, so there is no separate battery platform to buy into. If your shop, crew, or truck already runs M18, this is an easy add-on. It also includes overload protection, which is important for a portable inverter like this because it helps protect both the unit and the connected electronics when the load exceeds what the power supply is designed to handle.

Who is this for? Electricians, HVAC techs, plumbers, maintenance crews, service pros, remodelers, and anyone building a mobile workstation around the Milwaukee M18 platform. It also makes sense for serious DIY users who already own M18 batteries and want a clean way to keep devices charged during projects, power outages, camping, or travel. If your goal is portable power for laptops, phones, compact lights, and similar electronics, this is the right tool. If you need to run high-draw power tools, heated gear, kitchen appliances, or other heavy loads, this is not the unit for that job.

A smart add-on for anyone already running M18

The Milwaukee M18 TOP-OFF 175W Power Supply is one of those tools you do not think you need until you are on a service call with a dying phone and no outlet in sight.

• Who it's for: Pros and serious DIY users who already own Milwaukee M18 batteries and want portable charging power for phones, tablets, laptops, lights, and other small electronics.
• Why it stands out: The mix of a 120V outlet, 45W USB-C PD, USB-A charging, compact size, and the fact that it works with all M18 batteries makes it a genuinely useful platform accessory.
• Worth knowing: This is for small devices and electronics, not high-draw tools or household appliances. It is sold as a bare unit, so battery and charger are separate.

• What battery system does this power supply use? It fits all Milwaukee M18 batteries.
• How many devices can it power or charge at once? It can charge or power up to three devices at the same time using the AC outlet, USB-C port, and USB-A port.
• What is the USB-C output? The USB-C port provides 45W Power Delivery.
• What kinds of devices is it intended for? Milwaukee lists it for small electronics and personal devices such as laptops, cell phones, TVs, and similar equipment.
• Does it include overload protection? Yes, overload protection is listed in the product specifications.