Milwaukee M18 Power Supply Review

Milwaukee M18 Power Supply Review

How many times have you been working on a job site and you don’t have power where you need it?  My guess is a lot.  When you don’t have a power source, you usually need to turn to a gas-powered generator.  However, there are plenty of times when a generator is more of a pain or can’t be used because you are indoors.  So what options do you have?  How about a battery-powered power station?  Today we check out the Milwaukee M18 Power Supply Review to see if this is a viable option.

Milwaukee M18 Power Supply Review Overview

There are a lot of companies that claim they have an option for battery power that can run high-demand tools and other items but very few can actually deliver the energy needed for a job site.  So when Milwaukee designed a power station based on their M18 battery platform, we had to see how this stacks up. And if it really holds up to the claim of having portable power that can run high-demand tools.

Milwaukee M18 Power Supply Review Features

The Milwaukee M18 Power Supply (2845-20) delivers 3600 starting watts with 1800 running watts.  You can power up to 15 amps using the power supply.

The power supply must be powered by four Milwaukee M18 batteries.  While you can use any of their M18 batteries, you will get the best performance with the M18 12Ah batteries.  All the batteries slide in from the top which makes it easy to not only swap out or remove batteries but also see the fuel gauge of each battery.

Milwaukee M18 Power Supply Review

Here is a quick rundown of the amount of usage you can expect with 5Ah batteries compared to 12Ah batteries.

Milwaukee M18 Power Supply Review

On the side of the unit is where you plug in the included charging cord to charge the batteries. However, the Milwaukee M18 Power Supply does not offer pass-through power. In other words, the unit must be turned off to charge your batteries. When the unit is powered back on, charging stops.

Milwaukee M18 Power Supply Review

On top of the power supply, there is a handle that makes it easy to carry and move around the job site. This handle also has an “anti-theft” feature. You can slide the side bars over the batteries, install a padlock, and keep your valuable batteries from “walking away”.

Milwaukee M18 Power Supply Review

As with all Milwaukee tools they are made for the job site where conditions can be harsh.  So Milwaukee designed this with a cage to protect from drops or large items falling on the unit.

On the side, there is a push button to turn on and off the power supply, plus you can see the battery fuel status. We recommend using four batteries of the same amp hours. When one battery runs out, you’re done. If you use three 12Ah batteries with one 5Ah battery, when the 5Ah runs out, the unit turns off regardless of what is left on the 12Ah batteries.

Milwaukee M18 Power Supply Review

Below the power button, there are two (upside down?) 120V AC outlets to power your tools and also the charging receptacle when you’re ready to charge the batteries. The unit simultaneously charges all four batteries at a standard 3A rate.

On the right, there is one USB-A and one USB-C outlet.  So while this unit will power high-demand tools, it will also safely charge sensitive electronics like your phone with pure sine wave output.

Milwaukee M18 Power Supply Review

If that is not enough, there is a place to attach a shoulder strap. Milwaukee offers (and we recommend) a shoulder strap (49-16-2845 Shoulder Strap) for easier carrying. The bare unit is roughly 28 lbs., and can be 40+ lbs. with four batteries. Save your back – get the strap!

Milwaukee M18 Power Supply Review Performance

So now we know the features but what about performance?

Before we get into the performance, I want to look at the functionality.  First, turning on and off the power station is extremely easy with a simple push button.  I like that the power supply shows battery status and it is easy to read.  I also like how the cage is formed to easily wrap and stow an extension cord around the unit. So that when you are ready to use the M18 Carry-On Power Supply, you always have an extension cord available.  Now, I’ll get into performance.

Over the years we have used a lot of different gas-powered generators and battery-supplied power stations. We found a lot we liked. However, some were more for recreational use and not always great for the job site.  Either because they weren’t designed to be durable and rugged enough, or there just wasn’t enough juice to run high-power-demand tools.

In the Milwaukee M18 Power Supply Review it performed great. We hooked it up with just a miter saw, and also the common job site setup of a miter saw along with a dust collection system? We were amazed.  Not only did it run both tools simultaneously, but there wasn’t any lag and no bogging down, even though we were cutting wood.  We were extremely impressed. I thought it might be a challenge for this M18 Power Supply Station, but this application didn’t even phase it.

Are there any cons? I think there are two: 1) Pass-through power capability would have been a significantly useful feature. 2) I need to mention, if you leave the unit on it will drain your batteries (at the rate of approximately an amp an hour), even if there isn’t any load. So this unit can not be used as a backup power source for something like a sump pump. And you’ll be dead in the water the next day if you forget to turn it off overnight.


Next on the list was a table saw and dust collection combination.  Again, the M18 Power Supply Station ran both without any hiccups.  Both started right away and even when running the saw through wood, the tools never bogged down.

Milwaukee M18 Power Supply Review Value

You can pick this power supply up at Home Depot for $699 (bare tool).  If you need portable, reliable power, $699 is a great price and worth the investment.  However, you still will need batteries to power this unit.  You can pick up four 6Ah batteries for $498 or four 12Ah batteries for $996.

I know what you are thinking (and you’re right), that can add up to be a lot of money.  However, this price is if you are starting from scratch and don’t have any Milwaukee batteries.  Most job sites utilizing the Milwaukee M18 battery platform will have more than enough batteries available for this 4-place charger/power station. So in reality, your investment may only be the bare tool.  If you do need to buy batteries, it will up the cost a lot, but not having downtime and actually having a tool that can handle the work? Well, it’s worth it.

Milwaukee M18 Power Supply Review Wrap Up

The bottom line, Milwaukee did a great job with the M18 Power Supply.  Not only is the design simple and practical, but it actually works and can handle the power tool demands on the job site.  If you are already invested in the Milwaukee M18 battery platform, this is a great addition as you never know when you’ll need power in a powerless location.  If you do have to invest in the power supply and the batteries, it’s nice to know that Milwaukee has one of the largest lines in the market so you can grow into a quality power tool line. And this M18 Power Supply is covered by Milwaukee’s standard 3-year warranty.


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