
I learned a couple of things about the new Milwaukee M18 Top-Off USB-C charger at their recent Pipeline media event.
In this series of “Pipeline Secrets” posts, I’ll be discussing details, features, or reveals that came to light at the media event, the kind that you are unlikely to have heard about yet.
As you might have seen in my launch post (I’ll include the link below), the new M18 Top-Off (model 2847) is a two-way charger. It can be used to charge M18 Li-ion batteries, or you can use an M18 battery to recharge your electronics devices.
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This model is being sold alongside the other M18 Top-Off that features a low-power AC outlet, which is not present here.

The new M18 Top-Off is sold with a 65W USB-C wall adapter and cable rated at 100W.

Milwaukee will also be selling a 120W charging brick separately.
Why does the Top-Off come with a 65W charger? Why will Milwaukee be selling a 120W charger?
Here’s where the first secret feature popped up. Milwaukee designed their chargers for continuous use.
Here’s a quick rundown of the new Top-Off USB’s M118 battery charging times:
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- M18 2Ah battery: 42 minutes
- M18 5Ah battery: 105 minutes
- M18 12Ah battery: 230 minutes
That’s nearly 4 hours to recharge a 12Ah battery, which isn’t terrible for such a compact charger. Still, that’s nearly 4 hours of charging and thus heat generation.
I was told that a lot of USB-C charging adapters are designed to be fast, but with prolonged charging many will begin thermally-throttling their charging rate.
Thus, Milwaukee designed their chargers for continuous use, to avoid surprise delays when using the Top-Off to recharge your M18 batteries.
If you buy the Top-Off USB-C, don’t toss the included charger into your spares bin.
How will you know if your charger isn’t up to the task of recharging an M18 battery as its maximum rate of 100W?
(Note: the maximum charging rate requires the 120W charger or a separate charger, and isn’t achievable with the bundled 65W power adapter.)

A little turtle LED indicator light that will turn on when you’re not charging an M18 battery as fast as possible.

The turtle light, indicating a slower charging speed, is hidden when the device is unpowered or when you’re using a charger that can deliver at least 100W of power continuously.
Thus, if you use a power brick with at least 100W single port output, you might charge an M18 battery at the full rated speed – at least at first. If you’re using a 3rd party power supply, which many of us would be inclined to do, and it thermally throttles down the power after time, the turtle indicator light will be the only sign of this.
I asked Milwaukee why they are launching their own 120W USB-C power adapter that can be used with the M18 Top-Off charger, rather than letting users rely on the many 3rd party power bricks out there, and their answers made a lot of sense.
I also really like the turtle LED indicator light. It’s completely hidden if you’re charging at max rate, but will light up if you’re using an underpowered charging brick or your non-continuous-rated power brick throttles down to avoid overheating.
The turtle is a very subtle feature, but helpful and well thought out UI (user interface) inclusion.
Learn More: New Milwaukee M18 Top-Off Charger Does 2 Things
Jared
That’s pretty slick. It makes me wonder how my Dewalt USB-C charger compares. It’s also spec’d with a 65w power supply and is 100w max – maybe it’s slowing down and just not telling me? It would be handy to know.
Interestingly, I’ve found the 65w Dewalt adapter is enough to power my laptop (which came with a 90w adapter), even though most 3rd party 65w adapters aren’t. I figured that out because I sometimes use it to charge my laptop off my Dewalt batteries, then tried just the adapter when I had 120v power. It made me wonder if the third-party adapter companies were cheating on their specs – maybe it’s just that Dewalt made a better 65w adapter to match up with the charger?
Until that experiment, I just assumed all 65w adapters were 65w.
Bonnie
Are those other chargers multi-port? Some of those list the combined max power, but can’t deliver it all via one port.
Also USB-PD has several sub-types/revisions, and if your laptop uses a non-standard voltage (ie charges at anything other than 20V) it won’t be able to get the precise voltage it wants from older or cheaper PD chargers that only provide a few fixed intervals.
Stuart
I was already familiar with the new Top-Off charger, so I asked “why buy Milwaukee USB-C power adapters when there are many power adapters and modern GaN adapters on Amazon and elsewhere?”
Maybe the Dewalt is also rated for continuous use – I don’t know.
I didn’t realize that consumer power bricks could throttle down.
chip hershberger
I am not sure why you would want this top off,except for heated gear.
The og top-off will run a propane heater with a 6 for 2 hours.
Making it a replacement for the heater that was recalled.
https://www.homedepot.com/p/Mr-Heater-Contractor-Series-60-000-BTU-Forced-Air-Propane-Outdoor-Space-Heater-with-10-ft-Hose-and-Regulator-MHC60FAV/316812709
Stuart
It’s a compact M18 battery charger and also a USB-C power source.
Saulac
It took too long to get here. Will it ever get to the point of having the AC charger built in? An AC inverter?
Stuart
If you want built-in AC conversion, why not buy a regular charging dock?