Milwaukee Tool has never been a company that shies away from innovation. From the first cordless drill to the battery platform that powers everything from circular saws to heated jackets to a dragster, Milwaukee has consistently pushed the boundaries of what a tool company can ask its customers to spend money on. Now, the venerable Wisconsin toolmaker has done it again.
Introducing the Milwaukee M18 Top Off Battery Charger, a revolutionary new device that lets you charge your M18 battery using another M18 battery.
What Is It?
The M18 Top Off Charger is elegantly simple in concept. You have a dead Milwaukee M18 battery. You also have a charged M18 battery. You connect them both to the Top Off. The Top Off then transfers charge from the second battery into the first battery—albeit slowly, inefficiently, and at a premium price point.
“We asked ourselves: what is the number one pain point for M18 users?” said a Milwaukee spokesperson that we definitely did not make up. “The answer was unanimous: Outlets. People hate outlets. They’re on the wall, and that wall is often so very far away.” Milwaukee engineers worked tirelessly to solve this problem using a process that they described as “technically possible.”
The result is a device roughly the size of a deck of cards that connects two M18 batteries together and transfers approximately 60% of the charge from one battery to the other, with the remaining 40% presumably going to heat, vibration, and occasionally a faint smell of ozone.
Design & Build Quality
Milwaukee’s legendary red-and-black aesthetic is fully on display here. The Top Off is constructed from the same glass-filled nylon housing found across the entire M18 lineup. It’s also incredibly durable, which is good, because most users will likely throw it aggressively in the back of their work trucks while trying to remember where they put their actual charger.
There are two battery ports, conveniently labeled DONOR and RECIPIENT. An LED indicator strip shows the transfer progress in real time, cycling through green, yellow, and red before ultimately displaying an icon that appears to be a battery shrugging.
The unit ships with a Quick Start Guide, a warranty card, and a fold-out sheet listing the 14 scenarios in which using the M18 Top Off will void your Milwaukee battery warranty.
Performance
In our testing, charging a fully depleted 5.0 Ah M18 battery using a fully charged HD12.0 FORGE battery took approximately 45 minutes and yielded a Recipient battery at 58% charge. The Donor battery still retained a 20% charge, meaning the M18 Top Off successfully turns one good battery and one dead battery into two mediocre batteries.
To be fair, transfer speeds should improve dramatically when using Milwaukee’s forthcoming M18 Top Off RAPID+ model, which charges a dead battery 40% faster by simply requiring you to use two Donor batteries instead of one.
Milwaukee confirmed that the M18 Top Off Battery Charger does not include an input battery, an output battery, or the standard charger needed to recharge the battery that charges the other battery. That charger is, of course, sold separately.
When asked why a product called the M18 Top Off Battery Charger would require users to also own a different charger, company representatives emphasized that the product name had already been finalized.
Reaction from contractors has been mixed, with some praising Milwaukee for once again innovating within the cordless space, and others quietly staring at the product for several seconds before saying, “Wait.”
Pricing & Availability
The Milwaukee M18 Top Off Battery Charger is available now at your local home improvement retailer for $79.99 as a bare tool. For customers who already own more than six M18 batteries, Milwaukee is offering the Top Off 6-Pack Bundle, which comes in a custom Packout tray and includes a laminated card desperately explaining why you should buy it.
The Bottom Line
The Milwaukee M18 Top Off Battery Charger represents a genuine milestone in the history of energy transfer technology. It is the ouroboros (go on, click the link) of cordless power and available for the bargain price of just $49.99 before tax. Overall, we give it five stars out of ten, adjusting for the fact that two of our remaining stars ran out of charge during testing and are currently connected to each other via the M18 Top Off Charger in our break room.
