If you've followed our coverage of the 2018 New Products Symposium, you'll be well aware that the new Milwaukee 12 Ah high output battery is being used on the M18 system. It's not just about extra capacity, though. Aside from the fact that 12 Ah battery packs aren't alone, there's some serious technology worth talking about.
Let's dig a little deeper into the new battery and see what we can find.
The Milwaukee 12 Ah high output battery is still an 18V battery. A quick calculation (or looking at the bottom label) tells us that you're getting a total of 216 watt-hours of energy storage. Here's how it compares to some other Milwaukee batteries:

- 567% more energy than a 3.0 Ah M12 battery
- 233% more energy than a 6.0 Ah M12 battery
- 500% more energy than a 2.0 Ah compact M18 battery
- 140% more energy than a 5.0 Ah M18 battery
- 33% more energy than the 9.0 Ah M18 high-demand battery
footprint
To get this capacity, some changes had to be made to the Milwaukee 12 Ah high output battery. The 9.0 Ah High Demand battery pack uses 15 cells – three packs of five 18650 cells (3P5S). To jump up to 12 Ah, Milwaukee could basically try adding a fourth plate, but that would be a cooling nightmare. Therefore, the new battery pack contains 15 cells of the 21700 size. They're longer and wider than the 18650, so you'll notice an increase in size even beyond the 9.0 Ah battery pack.
This one measures 3.89 inches tall, 3.38 inches wide, and weighs 3.35 pounds. That's a big pack for an 18V battery. Nonetheless, Milwaukee High Output Batteries are compatible with all Milwaukee M18 and M18 Fuel tools. You probably don't want to use it on something like the Milwaukee Surge.
The Milwaukee 6.0 Ah high output battery isn't half the size – it doesn't use the same 21700 cells so it's a 10 cell pack.
strength
There's not much to gain in getting another 3 Ah of runtime with a battery of this size. Milwaukee doesn't just focus on making batteries for 18V batteries that are capable of delivering much higher wattage than standard batteries. It's still 18 volts, just capable of delivering more current (amps) without overheating.
More Power, New Motor
The new battery opens the door to more power, and with it the possibility of a bigger motor to take advantage of it. You'll see the divide between small brushless motors for compact tools like drills and impact drivers and larger brushless motors for larger tools like the new 9" grinder and table saw in the M18 Fuel series .
Performance
I'm still waiting for some new tools from Milwaukee to come out of the "next breakthrough" series designed around high output batteries. However, I got hold of the new M18 Fuel Super Sawzall and did some testing with a couple of batteries, including a Milwaukee 12Ah high output battery pack.

In the speed test, the high-output battery pack was 22 percent faster than the 9.0 Ah battery pack and 13 percent faster than the 5.0 Ah battery pack. All batteries are fully charged, so I don't know why 5.0 is faster than 9.0. But that's the result of the average cutting speed.
Excitingly, tests of cutting pressure-treated wood with embedded nails didn't push the new batteries to their absolute limits. So, while we've seen a significant increase in performance, it's possible to get even more on things like grinders.
We will continue to run tests as much as possible and update this article with results.
the bottom line
The Milwaukee 12Ah High Output Battery Pack doesn't just increase battery capacity, it dramatically increases the available wattage the Milwaukee can draw from it. The result was that it validated Milwaukee's claim that the M18 wire was not capable of reaching 18 volts.
The new battery has a large footprint, but we can expect to see it power larger tools. There have been Super Sawzalls, table saws, 9-inch grinders, and more under the M18 Fuel name. This is just the beginning, so what's next?
I think we can definitely rely on another miter saw – perhaps a 12" model. I'm counting on more rotary hammers and maybe an M18 fuel mower to extend the OPE.
One thing's for sure—they can match the power output of several 15-amp tools these days. But could we see a shift next to the 2 battery system?
No indication so far, but going this route will cover almost any tool that runs on a 110V outlet, regardless of current. If you've dreamed of a completely cordless workplace with zero compromises in power, Milwaukee has the batteries to power it.
Milwaukee 12 Ah High Output Battery Key Features
- REDLINK Intelligence: Provides optimized performance and overload protection using system-wide communication between tool, battery and charger
- Class-leading construction: Provides long-lasting performance and optimal protection against job site conditions
- Onboard Fuel Gauge: Displays remaining runtime
- Versatility: Powers over 150 M18 wireless solutions
Milwaukee 12 Ah High Output Battery Specifications
- Model: Milwaukee 48-11-1812
- Battery: M18 12.0Ah
- Dimensions (L x H x W): 6 x 3.9 x 3.4 inches
- Weight: 3.35 lbs.
- Price: $199