It is expected that Milwaukee will formally announce a new M18 Forge 12Ah battery pack this year at their next Pipeline media event.
We don’t have any details yet, but that’s also not the point of this post.
Here, we’re going to get you up to speed with a quick overview of background info. Think of this as a sort of Pipeline prologue, so that you can better understand whatever is said about the next Forge battery everyone is expecting.
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We’re going to go over a lot of “what,” but not a lot of “why,” and I’d be glad to elaborate on any part in a follow-up.
Although I said this will be a quick overview, I meant relatively quick. The new Forge battery is going to be 3rd-generation cordless Li-ion technology, or 4th depending on how you treat it.
First-Gen M18 Lithium-ion Batteries
Each cordless power tool battery has energy storage and circuitry to manage it all.
Shown above is what a typical Milwaukee M18 XC-size cordless power tool battery looks like on the inside.
There used to be 2 cordless power tool battery sizes – compact batteries, and extended capacity batteries.
Have you ever used AA or AAA batteries? Rechargeable Li-ion batteries are nothing like that, but maybe the visualization can help.
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Years ago, compact rechargeable Lithium-ion (Li-ion) batteries had 5 battery cells, and higher capacity batteries had 10.
Over time, battery cells with greater charge capacity were made available, and runtime was extended.
There were differences in performance early on, such as with cold tolerance, but we’re going to skip all that.
The main differences were with energy capacity.
Essentially, the storage density increased. Consider calories. Let’s say you have a bottle of flavored water with 10% juice. You have a bottle of the same size, but with 100% juice. Which bottle has more calories? It’s kind of like that.
As Li-ion battery tech continued to progress, the energy storage capacity increased.
This allowed for 2 things – i) the same tools could work for longer, and ii) new tools could draw more power and still deliver usable runtime.
Brushless Motors
Milwaukee – and other cordless power tool brands – introduced tools that were engineered with brushless motors.
What you need to know is that brushless motors, while more expensive than those with brushes, are more efficient.
Greater efficiency allowed for 3 things – i) similarly capable tools could work for longer, ii) new designs could draw more power and still deliver usable runtime, iii) balanced improvements with both greater power and longer runtime.
Serial vs Parallel Connections
Here, hold a 50 pound weight, please.
It’s up on shelf, too high for you to reach. A friend comes along and you stand on their shoulders to reach the weight. You pick up and hold the weight until your arms tire. You are weightless, and so you and your friend are supporting the same 50 pound weight. That’s analogous to serial connections, in a very loose way.
Next, after you rest for a bit, hold a 100 pound weight.
The weight is placed on a lower shelf. You and your friend can both support the weight at the same time, lightening the load. That’s analogous to parallel connections.
When you connect 2 battery cells in series, you add their voltages together. When you connect 2 battery cells in parallel, you add their charge capacities together.
Imagine drinking out of a bottle of water with 2 straws. Insert the end of one stray into the other to approximately double the length. That’s a serial connection. Drink from the bottle of water with the straws side by side. That’s a parallel connection.
Two straws side by side let you drink more water faster. Two straws end to end let you drink from the bottom of a taller bottle, something that has no easy analogy in an electrical engineering sense.
Taking another look at these Milwaukee M18 battery cell arrays, you should see that there are 10 battery “cells.” Don’t be concerned about how they’re connected.
Each cell has a nominal (working) voltage of 3.6V. 5 cells in series will have a working voltage of 3.6V x 5 = 18V. Batteries that are labeled “20V Max” are no different. The “Max” part refers to the maximum measurable voltage of a freshly charged 18V battery pack that is not yet powering a load.
Okay, so 5 cells in series is 18V. What about 10 cells? Each array of 5 cells is arranged in parallel.
This would be described as a 5S2P battery pack. 5 cells are in series, and each array of batteries in series are in parallel.
Lastly, here’s a 100 pound weight placed on a very high shelf, way out of reach. You have 3 friends with you.
Each person is weightless. You climb onto your friend’s shoulders and ask the other 2 to do the same. With you and a friend both standing on the other friends’ shoulders, you hold the 100 pounds and share the work of supporting the load. Every person is now holding 50 pounds.
In a cordless power tool battery, the voltage won’t vary for a particular platform. That is, Milwaukee M18 batteries with Li-ion rechargeable battery tech will always have groups of 5 cells in series. Whether there were additional groups of 5 cells in parallel used to be the only thing to consider with respect to power delivery.
When holding a weight – that’s the load. In the context of cordless power tool batteries, the load isn’t a physical weight, but a device – usually a motor – which consumes electrical power.
Similar to having help from a friend to support a heavy weight, batteries configured in a parallel configuration can have lighter demands from an electrical load.
If you connect two batteries in parallel, and the load remains constant, each battery will drain half as fast as if the same load was carried by just one battery.
Milwaukee M18 High Demand
In the image here, there’s a compact battery (5 cells), a Milwaukee “XC” eXtended Capacity battery (10 cells), and an HD High Demand battery (15 cells).
In the High Demand battery, there is an array of 3 sets of 5 cells.
Remember the 50 pound weight I asked you to hold? Sure, you could pass it along to someone else when your arms tire. But what if I asked you to hold a 150 pound weight? With 3 people holding it at the same time, it’s as if you’re just holding a 50 pound weight.
The more simultaneous support you have, the greater the load you can hold.
As a group, 3 people of comparable strength can hold more than 1 or 2 of them.
Thus, when Li-ion battery tech reached the peak of its potential, a shift towards 15-cell Li-ion batteries allowed for higher powered tools. It also delivered longer runtime. In some cases, it allowed for tools that were both higher-powered and longer lasting.
Second-Gen Cordless Battery Tech – High Output
Imagine a classroom filled with 10 kindergarteners. You add 5 more. What happens to the noise level? You then add 5 more.
How many kindergarteners can you add before there are problems?
At some point, the room will reach capacity. Frustrations will rise. Laughter will give way to screaming and crying about how Alice isn’t sharing the blocks, and James is hogging all of the blue crayons.
There’s only so many kindergarteners you can practically fit into a classroom. Now, give them all cupcakes. Does the number change?
Increase the size of the room, and you can fit more kindergarteners. Makes sense, right?
Increase the size of a Li-ion battery cell, and you can increase the energy storage without suffering from the same types of complications as with smaller sizes.
What’s the main issue with increasing the energy storage density of a Li-ion battery? HEAT.
Surely you must have noticed that your phone heats up when charging. Charging or discharging a battery involves the flow of energy, and a property called internal resistance.
Do you get cranky after a long work session, where you’re hot, sweaty, hungry, and tired? How will you respond if someone asks you to do some mundane task before you can rest and recover?
Milwaukee’s High Output batteries have greater charge capacities – energy storage – but also lower internal resistance, and can deliver greater output than batteries engineered with smaller Lithium-ion battery cells.
The difference is enough where a 5-cell High Output battery can deliver around the same power as a 10-cell battery that’s built with the first-gen Li-ion tech. Or, a 10-cell High Output battery can deliver around the same power as a 15-cell battery built with first-gen tech.
AND, it also means that a 15-cell High Output battery can deliver around the same power as… nothing that came before it.
Even with lighter loads, the 15-cell High Output batteries would run cooler than others.
Milwaukee’s First FORGE Battery
Milwaukee Tool’s first FORGE battery was introduced last year.
It is advertised as delivering the most power, fastest charging, and longest life. The Milwaukee M18 FORGE 6Ah battery delivered comparable charge capacity to the existing 6Ah battery, but greater power levels.
The 6Ah battery features different Li-ion technology, with the internal batteries being “pouch” cells, rather than cylindrical.
Amp-Hours
Amp-hours (Ah) refers to the charge capacity of a battery.
Let’s say you have a 6Ah battery. In theory, this means that it has enough energy storage to power a 1-amp load for up to 6 hours, a 2-amp load for up to 3 hours, a 6-amp load for up to 1 hour, a 12-amp load for up to 30 minutes, and so forth.
If you see the terms Watt-hours, that’s a measure of energy capacity, or Voltage x Amp-hours.
None of this describes the power delivery of a battery pack. There are ways to describe the maximum power output of a cordless power tool battery, but the industry does not do this.
Tabless Battery Cells
“Tabless” describes the engineering of the rechargeable Li-ion battery cells used in next-generation cordless power tool batteries.
These images, courtesy of Bosch, do a good job of showing the physical differences.
Imagine – yes, again – a room full of kindergarteners. THE ICE CREAM TRUCK IS HERE!!!
What happens at the door to the room? There might be some crowding as say 20 kids try to exit the door all at once, and at the worst some pushing and screaming.
Now, instead of a room with just one or two doors, imagine all the kids are sitting under a large canopy tent with an unrestricted and open side. They’re going to run out of the tent almost unrestricted, right?
Energy flow, without going too much into technical details, is similar.
With “tabless” Li-ion battery designs, there are so many more pathways, rather than just one or two.
As a result, a “tabless” battery cell can deliver much greater power and remain cooler under heavy loads.
What to Expect with M18 FORGE 12Ah
We are expecting Milwaukee to announce an M18 Forge 12 Ah battery. There could be more than this, in which case everything said here still stands.
It is expected that the Forge 12Ah battery to be Milwaukee’s most powerful yet.
Let’s put everything together.
M18 First-Generation Battery Tech – small 1-door room with 20 kids
M18 High Output Battery Tech – large 2-door room with 30 kids
M18 FORGE Battery Tech – large open-wall room with 30 kids
ICE CREAM TRUCK!! Which room empties the quickest?
What if there’s something less exciting, such as if you’re giving out carrots to one kid at a time? You’re going to see less of a difference – if any.
Here’s a big question – What kinds of new tools might an M18 Forge 12Ah battery be able to power?
Milwaukee’s cordless power tool and battery technological advances tend to be introduced in waves. First comes new battery tech, then comes an expansion and the next generation of cordless power tools.
Sometimes the battery tech is ahead of the tools, sometimes the tools are ahead of the batteries.
The M18 Forge 6Ah battery allowed for high power delivery in a smaller and lighter package. The expected M18 Forge 12Ah battery is expected to deliver higher power delivery than the existing High Output 12Ah battery.
It is expected to raise the power delivery threshold. In other words, it will allow for increased capabilities.
For some of the same tools, the Forge 12Ah is expected to run cooler, which can also help it last longer.
Let’s say you have a jobsite radio that drains 1Ah of charge capacity every hour. A 6Ah battery might last 6 hours, and a 12Ah might last for 12 hours. Forge 6Ah and 12Ah batteries won’t provide runtime and power delivery benefits in this type of application.
The Forge batteries should provide performance and runtime benefits when powering tools that might overheat during heavy use. The exact benefits will depend on the type of tool.
The Forge 6Ah battery that launched last year can out-power the existing High Output 6Ah battery, and without a substantial increase in size. Consider that the 15-cell High Output 12Ah battery has 50% more Li-ion cells than the 10-cell High Output 6Ah and 8Ah batteries. The 6Ah battery is advertised as delivering comparable power as the 12Ah, but without its size and weight.
The Forge 12Ah battery will take the M18 cordless power tool into new territory.
This has happened twice now, first when Milwaukee introduced High Demand batteries with 15 rechargeable Li-ion cells in a 5S3P configuration, whereas only 5S1P and 5S2P configurations had previously been available.
Then, they introduced High Output batteries in 5S1P, 5S2P, and 5S3P configurations. The new High Output 12Ah battery increased the M18 cordless platform’s power delivery ceiling, again.
The M18 Forge 6Ah battery that launched last year did not do this, but the 12Ah is expected to.
Each new major advance paved the road for new cordless power tools and tech.
Dual Battery Tools
Keep in mind that two battery arrays in a parallel configuration can increase the amount of power that can be simultaneously delivered to a load, such as a power tool motor.
As you might have seen, Milwaukee has several M18 dual-battery cordless power tools.
Milwaukee does have a higher powered line of cordless equipment, MXFuel, but there’s a middle ground where some tools and equipment would still be fitting for their M18 cordless line.
An M18 Forge 12Ah battery with tabless cells is expected to deliver an increased power delivery ceiling.
While this would be great for single-battery tools, it should also be impactful in the context of dual-battery tools and equipment. We might finally see a Milwaukee M18-powered cordless dual stage snow blower.
Something like a cordless snow blower can really tax 18V-class batteries, even in a dual battery configuration.
I recently tested a different cordless power tool brand’s dual battery powered snow blower, and it ran on 15-cell batteries not too unlike Milwaukee’s existing High Output 12Ah batteries. Even with the tested unit being a higher voltage product, its two batteries, each in a 15S1P configuration, overheated before their full energy capacity could be discharged.
I would expect for 15-cell batteries featuring tabless cells – such as the expected M18 Forge battery – to perform better.
What Types of Tools Might Benefit from this?
Milwaukee has a single cordless air compressor, with 2 gallon air tank.
Maybe a Forge 12Ah battery will allow for a larger air compressor that still fills fast and doesn’t have any compromises with respect to duty cycle or similar.
Milwaukee has a cordless table saw with 8-1/4″ blade size. Maybe a higher powered battery will allow for a larger cordless jobsite table saw with 10″ blade size.
Milwaukee doesn’t yet have a cordless tile saw.
They launched their M18 Fuel 12″ cordless miter saw years ago. Maybe it’s time for an update?
Makita recently launched a new tabless battery, and their promotional materials featured performance comparisons for a wide range of tools. In each, they demonstrated improvements in application speed, runtime, and operating temperatures, when compared to batteries with similar charge capacity.
Makita advertises improvements ranging from up to 39% longer runtime to 26% faster cutting. In every example, the battery temperature was lower for the tabless battery than ones featuring Li-ion cells similar to those in Milwaukee’s M18 High Output batteries.
Even if we ignore any differences in application (drilling, cutting, grinding, etc) speed or runtime, lower temperatures could allow for lower downtime at the charger.
(If you’re wondering why Milwaukee isn’t launching a higher capacity battery pack with pouch cell technology similar to the 6Ah battery, it’s because tabless cells were found to have better thermal dissipation and deliver faster turnaround. This is based on hurried conversations a year ago, but it makes sense – Forge is about next-level battery technologies, and not necessarily just pouch cells.)
We don’t yet know what Milwaukee will be revealing over the next few weeks and months, but we can anticipate major news.
The Forge 12Ah battery will likely be just part of the story.
Questions?
This post was intended as a condensed primer to bring everyone up to speed about the fundamentals.
I skipped over technical aspects – notice how I didn’t refer to “electrical current” even once – and took the liberty to create analogies that were easy to grasp at the expense of technical accuracy.
Okay – one more analogy. Voltage is akin to the pressure in a water hose. The greater the pressure, the further the distance it will spray out. Current is akin to the water flow. High Output is similar to increasing the internal diameter to allow for greater flow. Tabless batteries are like a soaker hose, where water can leave the hose along the length rather than just at the end.
Please ask any questions you might have!
And for ToolGuyd regulars who can teach a masterclass on cordless battery tech – please feel free to nitpick! I’ve learned over the years that “kindergarteners in a room” can help explain all kinds of physics concepts. although sometimes at the expense of technical accuracy. I’m open to new analogies, just keep in mind that the goal is to get everyone up to speed on 16 years of M18 cordless power tool battery tech.
Leo B.
Exciting possible development! The rear handle saw would be a nice application, especially if the battery is lighter. SDS drills, miter saws, the table saw, and cut off saw are all good tools to use this battery on. Looking forward to seeing what’s in store at Pipeline! Maybe a lighter weight framing nailer in the next year or two.
Stuart
I don’t expect the Forge 12Ah to be smaller or lighter than the current High Output battery.
The Forge 6Ah would be the better choice where battery size and weight are a priority.
The problem with framing nailers isn’t the battery source, but in transforming electrical energy into mechanical.
Dave
The Forge 6.0 is smaller and lighter than a High Output XC 6.0.
Why wouldn’t a Forge 12.0 follow suit?
Farkleberry
If I understand the article correctly, the Forge 6.0 uses pouch cells for its weight savings vs the cylindrical HO 6.0. Cylindrical cells are used in both HO and Forge 12.0 batteries because they offer superior cooling, so same size and weight but with tabless efficiency gains in Forge 12.0
I understand the pouch cells offer greater flexibility in form factor, but am skeptical of their durability if there are many of them stacked together tightly. If they have a lot if room in between, then is the only advantage the weight of the plastic pouch vs the metal cylinder walls?
Do pouch cells offer any other advantages in general?
I’ve not noticed any advantages with the lifespan of the pouch cells in tablets and cell phones vs 18650 in tool batteries, flashlights, etc.
I understand there is a compromise on making cells larger in diameter or pouches thicker vs heat dissipation. Are these pouches each 3.7 volts and will this change over time (a question for Milwaukee engineers maybe?)
Dave
How do we know the Forge 12.0 will have cylindrical cells? I would expect it to have pouch cells like the Forge 6.0.
Stuart
Because I asked the engineers and managers who were designing it.
Dave
Thank you, Stuart.
Stuart
You’re welcome!
Things could have changed since these conversations took place in August, but I seriously doubt it.
Stuart
Cooling.
Tabless cells provide for a superior user experience.
Think draining battery in a high demand application and then recharging it to go again. As it was explained to me last year, tabless won out.
There could be other factors too, such as cost, but better cooling was the top consideration. We’ll know more when it’s officially discussed.
Dave
Oh I see now that you were responding to me.
I guess we will see. I love the smaller form factor of the Forge 6.0, so I’m hoping they figured out how to keep temperatures down and still use pouch cells for the 12.
Leo B.
Understood- the weight isn’t terrible on the saw with a regular HO 12 AH battery now, so at least similar weight with more power would still be a plus. For the framing nailer, that was more of a general thought on Pipeline. Weight is one of the only cons of the M18 Fuel nailer right now, so if that’s meaningfully addressed, then it’d be the best on the market with no asterisks. Milwaukee tends to do a better job with the second generation of their nailers, so I’m excited to see what’s in store.
Stuart
I don’t mean to be pessimistic about framing nailers, it’s just that they’re governed by different engineering principles and constraints than other types of tools.
The priority – as I understand it – is in nail driving power, speed, and recycle time.
Everyone wants smaller and lighter nailers, but it might take completely different and groundbreaking engineering to accomplish that.
V
Honestly I would love to see more tools on the M12 platform. For example,
1. Bosch has a 12v trim router… I would love a M12 version.
2. A M12 Car Battery Starter. (I doubt they would do that)
3. Updated brushless right angle drill
4. Updated brushless variable polisher
5. A Rivet Nut Gun. Similar to the M12 rivet gun.
Jay
Good article. What I want to know from Milwaukee:
How many Watts does each battery deliver?
What has been done to eliminate bottlenecks? Melted terminals for example.
What has been done to avoid overheating of the tools?
Which tools has been designed to take full advantage of Forge batteries?
Stuart
Melted terminals was about vibration in one particular tool – the power head with trimmer attachment. That was remedied by redesigning the interface and implementing a rolling change in current production.
We talked about overheating 2 years ago when the new Fuel drill came out. They redesigned it for massive heat dissipation, and I haven’t heard a single complaint since then.
I’ll be able to tackle some of those questions when I learn more.
Richard Miller
Any idea when that change took place or how I can tell if mine is the updated version?
Stuart
When did you buy it?
I spoke to the manager about that and they said anyone who experiences problems can contact customer support.
This wasn’t a recent update. I haven’t seen before and after images to know the exact changes made.
Richard Miller
2-ish years ago???
Stuart
I’d say that if you haven’t had problems yet to not worry about it.
If something comes up, Milwaukee will take care of you. If not, get me involved.
Richard Miller
Thanks. BTW, I generally have really good “luck” in working through customer service problems. Be persistent + be super kind and respectful = resolution (most of the time). In the off chance this isn’t enough, actively helping them find ways to solve the problem within their constraints unlocks more. If you are authentically the nicest person they have dealt with that day, MOST people WANT to solve your problem.
Marko
The subtitle on the main page reads “Let’s dig into 16 years ___if___ Milwaukee M18 cordless battery tech!”, you may want to correct it.
Stuart
Thanks! *fixed*
Daniel
Very excited about a forge 12.0. I’m a professional carpenter and would love to have a full 10” table saw and more runtime/power in the cutoff saw (it currently eats 12.0 batteries as snacks)! Also very thankful Milwaukee has stayed competitive in the 18v platform and not pushed to new battery sizes (36v, etc).
Farkleberry
I would love to learn more in future posts and maybe some could be asked when you visit with Milwaukee. I remember you talking about how receptive they are and how available they make their designers and engineers. I’m also constantly drawn back to this site by the collective knowledge of the commenters.
Here are some rapid fire questions (and some opinions):
I know Milwaukee has said in the past they will stick with 18v, has anything changed beyond now going 18v x 2?
With so many competitors going to higher voltage systems, does Milwaukee not see this as a disadvantage?
Would there not be a way to add a multi voltage system that still interfaces with existing 18v, a la Metabo HPT’s multi volt or Dewalt Flexvolt, or are there patent implications?
I was curious about MX Fuel and checked out their website. No where in the many specs does it list the voltage. I had to google search and was directed to a general faq that stated 72v.
Is Milwaukee sensitive/worried about touting the benefits of the higher voltage MX because it might reflect poorly on their 18v high draw tools. If there no disadvantage to 18v large/high draw tools why offer MX in the first place?
I see people buying Ryobi 40v OPE all the time at HD, and all of the OPE brands are at 36v-72v.
Wouldn’t it make more sense for a snow blower and pretty all larger OPE to be MX?
I was curious about size/weight differences between the MX and larger 18v batteries. One 72v MX 3 ah battery is 6 lbs while two 12 ah 18v batteries are 2 x 3.5 = 7 lbs. Both setups are 216 watt hours.
I really think there are few advantages to 18v OPE. I can’t think of many tools I’d want to run with a compact 5 cell pack, maybe a mini pruning chainsaw but probably not because of run time and cooking battery in 1p config. Even power pruners might be better with a cord and belt pack like the new Makita sanders, etc.
18v “power tools” or general or carpentry tools, however, I really like running 5 cell packs on drills, impact drivers, multi tools, etc. when doing limited or lighter duty tasks and moving around a lot.
You had mentioned 40v compact size pouch cell packs were not practical, and this seems logical if they are 3.7 volts. I assume pouch cells could be designed to run at higher voltages, but may not be advantageous or economically feasible at this time.
How about Prism cells (for Milwaukee 18v and competitors’ compact 36v)? I just learned about them this morning after being spurred down the rabbit hole by this post. Sites like battery University say they’re not the best at cooling, or high draw, etc. but that neither are pouch cells, especially in a stacked configuration.
Farkleberry
I understand some major advantages of Milwaukee sticking with M18 versus introducing a higher voltage system: simplicity and momentum in marketing and customer base, etc.
I’m trying to understand the advantages of higher voltage systems, and why so many others (including Milwaukee MX) are adopting them.
There is obviously an opportunity to sell more new tools by introducing a new system. This also runs the risk of alienating existing customers (Makita XGT?).
Back to the electrical question:
I understand motors running at higher voltage are more efficient (more work done, less heat per watt consumed). The switches, controllers and wiring to the motor don’t work as hard, as they see less current.
What are the advantages to a battery pack wired 10s1p = 36v vs 5s2p = 18v?
Maybe the internal output wiring and connectors see less current (and heat) in 36v?
How about the straps connecting them together?
How about the battery cells themselves? Are they being taxed any differently?
JR Ramos
You might nose around batteryuniversity.com and it should help to understand a lot of these basics. Most of it really is just basic electrical theory plus a smidge that is applied to tools. Some of their articles are dated now but they are still relevant.
You almost answered your own question: understanding motors running at higher voltage –> advantages of higher voltage (cordless battery) systems. It’s mostly the same thing. The differences are in the details of DC power sources without a constant output (batteries) vs. constant electric mains supply. More voltage is more punching power – getting hit by an adult vs. hit by a child. To do this with batteries it takes combining them in circuits with advantages and disadvantages – most of which are just based on what can be supplied and tolerated by the individual cells. Switches often suffer more at higher voltage, and DC power is often rougher on switch contacts (normal switches) than AC but usually the engineers pick parts that are suitable so you don’t need to think about that (good reason for people to quit that habit of pulling a trigger a bunch of times like a toy, though).
But yes, a lot of it simply comes down to basic electrical resistance and resistance = heat. In the case of the individual battery cells that heat will cause the voltage to sag (both as the energy depletes in use but also under a heavy workload). So the voltage sags and let’s say your fully charged 18v battery (actually more…20v marketing…) gives 18 or 17 volts in use…ask more of it and the cells may only be able to put out 15 volts or even less. Some of that can be mitigated by using different cells that have different performance characteristics, or as Stuart wrote, balancing the load with various configurations of cells and/or quantity of cells. Electric mains motors behave differently here (under heavy load/overload the voltage from the outlet remains constant pretty much but the current draw (amps) can go way up, even double or triple the rated running amps). DC battery power can’t do it like that…so you turn to more/better cells in the pack, or you consider going to a higher voltage delivery design like 36v or whatever. More volts = more punch = the same tool can do the same work more easily or it can provide a higher work output depending on what they wish to do with the design.
The straps are a special nickel plated material – it’s available in hundreds of different thicknesses and material tweaks and end products. Same thing here with resistance – more resistance equals more heat, and since we know heat is something of an enemy to performance (and sometimes lifespan of battery cells or electronic components) then we try to reduce it. For the same current running through a part, generally, a piece of thicker metal will have less resistance/heat/voltage drop than a thinner piece of metal (think about electric wire gauges). Interface connections (battery to tool) are very similar except care needs to be taken to ensure a tight firm connection that doesn’t wiggle. The straps on battery cells are spot welded so they don’t move at all….removable batty packs need different solutions.
But check out the basics of electricity and learn those first…then most of this falls into place easily. Battery University is definitely worth your time – pretty exhaustive site but you can ignore the more techy entries until you’re ready to learn more.
And knowing this stuff will help you sift through the marketing fluff that is so prevalent still (and also the absence of basic info that they seem so loathe to provide). Like 18v vs. 20v “max”….it’s the same damn thing, just deceptive marketing, which DeWalt is famous for. In fact, DeWalt was the one to start this nonsense back in the NiCd battery days. Suddenly they had a “14.4” volt drill…woo! They’re just using the fully charged cell/battery specs (like right off the charger) instead of the “nominal” voltage rating, which is how the entire battery cell industry describes their products. Most lithium cells are manufacturer rated/described as 3.6v or 3.7v nominal voltage. They are safely max charged to about 4.2v for typical use. Simple math from there.
Yes, battery cells are taxed – if that tax is too heavy then you get all that extra resistance heat and voltage sag. In that case you live with reduced performance and greatly reduced run time, or you maybe choose a different cell that has better characteristics. This happens a lot and both the tool industry and the automotive industry have really driven advancements in this area over the last…call it a decade, with only marginal improvements in the last 5-6 years or so except the new tabless design. The changes in these cells are pretty technical but are tiny tweaks and variations to the chemicals inside, or sometimes the type or size of the electrode inside…whole huge subject there to understand the manufacturer products and the tech aspects (pretty neat to learn, though). The advances over the years have addressed exactly this taxation. Generally if you have a “high drain” cell that can handle a lot more current without getting upset, then those necessarily have a reduced run time capacity. On the flip side, increased run time capacity cells usually can’t handle the heat (some suffer a little, some fall on their faces). Now, we have a handful of products that are able to produce both increased capacity while still being able to deliver the beans, which has been awesome (for tools, e-bikes, cars, vacuums, etc). And changing from the original 18650 size to the slightly larger 21700 size really provided a ton of improvement (thanks to Tesla for that). It surprises me that the power tool industry hasn’t converted everything to 21700 at this point because it wouldn’t be hard to do and the gains are significant. So yeah, they choose the cells based on the expected taxation that they expect and are comfortable providing to their customers. And manufacturers have constantly switched cell types/cell brands in their battery packs, usually without saying anything to their customers…running upgrades so to speak, but not always.
Stuart
One correction – the engineers don’t always just “pick parts.”
Milwaukee has in the past worked with semiconductor companies to design and manufacture custom chips. I’m sure they can contract with switch manufacturers and others for bespoke properties as well.
JR Ramos
Well sure, almost everyone does that to one degree or another. That’s easy to do with electronics, and cheap, but as I’m sure you know it’s done with a myriad of parts and suppliers. Hard to simplify an education on a topic that encompasses a lot and that didn’t seem like something worth explaining or expanding upon.
Gotta love the Milwaukee engineers that spec proprietary threads on certain things, though…for no good end reason, just gatekeeping. Extra fine 9mm and 11mm threads…thanks for that, cheeseheads! 🙂
Stuart
You lost me.
DRT42
More voltage does not equal more punch, if “punch” is defined as torque. More current equals more torque.
You’ve got me on “taxation”. Sorry, genuinely not being an a**hat, but what in the heck are you talking about?
MM
Current is the relevant term in the equations but voltage is what drives current. Practically speaking more voltage often equals more punch if for no other reason than ohm’s law. V= IR. If R stays the same and we increase V, then we get more I (current).
I assume by “taxation” they are referring to electrical loading, not the financial term.
Stuart
No.
Ohm’s law typically applies to static values; if you know the current draw of a circuit and add a resistor, Ohm’s law helps you calculate the voltage drop across it.
Let’s say you have two motors, one 12V, and the other 18V, and they both draw the same amount of power to do the same work.
At the same power draw, a higher voltage motor will draw less current.
Lower current at the same resistance leads to lower voltage drop.
Resistance – and temperature – have current-dependent factors where the greater the current, the greater the temperature buildup and efficiency losses.
Consider that Watts = Voltage x Amps
Yes, V = I x R, but for most loads, the wattage is not user-controlled and won’t increase.
Increasing voltage is kind of like increasing the height of a waterfall. The water flow at the top of the waterfall remains unchanged. If you stand at the bottom, you’ll feel the difference in “punch.”
JR Ramos
They beat me to the voltage thing. And terms like that are just kind of dumbing things down to make the bare basic concepts more digestible to those who don’t have a foundation in electrical basics yet, right…the point of this and Stuart’s several other articles. Sometimes people get it, sometimes they don’t until some other comparison is communicated…some people give up and come back for another stab years later until things just click. I was like that myself, twice, until things fell into place…what helped the most was just learning about one thing and then branching off and going to a different area later, but that’s not always easy to do with something as complex as electrical theory and in combination with electronics to boot.
Yes, taxation….I was using his words there regarding…stress…on the cells.
Stuart
MX Fuel is a loaded question, as the system isn’t just about higher voltage.
Consider towing a trailer with a heavy duty pickup. Now take a compact sedan, drop in a bigger engine, and add a towing hitch. Can the wheels and suspension handle the load? Steering?
MX Fuel is an approach to powering the types of tools that classify as “light equipment.” Yes, the batteries are larger and can deliver more power, and they were designed for performance levels that are very difficult to achieve with the size of batteries centered around the types of construction tools you can buy at the neighborhood home center or hardware store.
Let’s say you have two battery packs. 18V: 5S2P, 36V: 10S1P. When you have current flow, resistance leads to energy losses in the form of heat. Voltage is akin to pressure, and current is akin to flow.
With higher voltage, you can achieve greater efficiency. This is why electric power is transmitted over long distance at higher voltage – there are less losses.
In many cases, higher voltage doesn’t necessarily lead to more power output. There’s the potential for it, depending on how the tool is designed.
What’s different between an 18V battery with 5S2P configuration and a 36V battery with 10S1P configuration if each is delivering say 400 Watts of power? Li-ion cells don’t know or care about the energy flow through them. The differences will be in the tool design – one would have an 18V motor, and the other a 36V motor.
A lot of engineering goes into the tabs connecting battery cells to each other and the battery management system (BMS).
The battery connections are one of many factors that can influence performance.
The last time I visited Milwaukee’s HQ, they let me walk around one of the battery labs, and I mentally cataloged the different types of research-grade equipment they have for deeply scientific analysis.
A lot of people think that tool brands order some battery cells from name-brand manufacturers, and slap them into a plastic housing with basic management circuit. I can’t speak for most brands, but I know that it’s not the case for Milwaukee.
JR Ramos
Can you share which packs/cells specifically that Milwaukee has OEM’d? Every cell I’ve seen from them has been straight up normal wrapping from the various manufacturers. In the rare cases where a custom cell has been agreed upon, the wrap changes and/or the imprint on the canister. They may spec A or B grade cells but going for some custom cell is a…a journey…and it’s not often that any of the big manufacturers are willing to do it since they have rather expansive catalog items to choose from. Or maybe you were talking about their construction and electronic components/boards….?
The last consumer product I can remember spec’ing custom cells were those awful 20700 that Dyson used and soon abandoned. And e-bikes got on the 26800 for a very short time and now that cell is I think completely deprecated (it was only made by two small time Chinese factories/brands and when the e-bike need dried up, so did that cell size). Automobiles and such…different story of course.
Stuart
What I’m saying is that it’s not as simple as spot-soldering tabs to off the shelf cylindrical battery cells.
Pouch cells are different.
JR Ramos
Right on…gotcha. 🙂
Jronman
Wasn’t the Forge 12 ah announced last Pipeline but was just coming later than the forge 6 ah.
Adam
Announced, but not shown. They might have well done that with the modified Packout handle that only took… a year to roll out. Just announce it, and not show it.
As it looked to be in final form last year, I didn’t anticipate it taking forever and a day to release.
I hope they put asterixis next to all products that they really have no clue on actual release
Stuart
The Packout handle was delayed by a few months, which is not out of the ordinary.
Stuart
It was mentioned and open for discussion, and they made it clear more information – and not a launch or release – could be expected in mid-2024.
Nobody held one in their hand.
Jason M
As far as new tools, I would firmly expect to see a 20” chainsaw, dual battery probably. Greenworks, Ego, Dewalt, even Ryobi have solutions and Milwaukee has a big gap there for arborists.
Snow blower makes sense since it was promised a few years ago, but since those are bought by retailers a season ahead and this battery hasn’t even been announced yet my guess is battery launch this fall and fall 2025 snow blower.
Others like you mentioned maybe a larger table saw and updated 12” miter but again I wouldn’t expect any major tool announcements to come along side this. They don’t want to repeat announcing the 9 AH battery along with the 9” cutoff saw and then having to delay both for years.
Personal wishlist would be powered wheel barrow and a solid earth auger but slim chances there.
Big Richard
Dual battery 20″ chainsaw is happening, model 2827. I know the -22 kit is $799.99 with 2x 8Ah batteries (not sure if they are the standard HO 8Ah or the new Forge 8Ah).
Big Richard
8Ah Forge coming as well, just a 2P version of the 12Ah so it makes sense.
Supposedly also some higher capacity M12 batteries, haven’t seen any hard evidence on that one yet though, so no guarantee.
MKY
Stuart –
[bunch of corrections]
Stuart
Thank you!! *fixed * – much appreciated!
Christopher Wilke
Stuart
In my fire department we are using allot of the 12AH batteries to run large ventilation fans. With the current 12.0 AH battery i have had issues and seen many reports on the internal cell “groups” going out of balance. IE one of the cell groups goes below 3.5V, out of balance with the remaining cells. This typically shows as fresh off the charger and only showing 3 bars when the check button is pushed
It’s my understanding that the current battery does have an internal balancing circuit but it can only balance while charging. Due to the large capacity of the 12ah batteries, the balancing circuit does not have enough time (especially on rapid chargers) to correct the voltage imbalance. If you speak with any of the engineers at the pipeline event can you please inquire about this? and if this has been addressed in the forge batteries?
thanks
Stuart
I haven’t heard of this before, and will definitely ask!
JR Ramos
That’s the first I’ve heard of their packs having any balancing at all. I’ve had a number of the 12v packs do this and short of disassembling and doing pony tricks there’s nothing you can do. The charger is just smart enough to recognize the problem but the charging system has not been designed to prevent it, which is just absolutely dumb…capital D Dumb. Milwaukee is aware of it and fields all the complaints…battery exchanges are sometimes done out of warranty but they do have a decent longer warranty to take care of you when this happens (it’s more often a When rather than an If). They’ve put some smarts into some battery packs lately than can give diagnostics on a limited level, but still no balancing in any meaningful sense.
I have a zillion Milwaukee batteries and because of the failures I had to start looking at the mfg date on the packs and try to use those the most/first, which goes against my usual approach to multiple cell usage. So far I’ve had to eat the cost of three packs but I’ve had I think seven replaced at this point. Besides the balance charging problem, it’s also partly an issue of them pushing the limits of the individual cell types they’ve chosen to use in various packs and they have constantly changed those over the years. Like the 12v 6Ah XC packs were using Samsung 30Q cells and failing all the time…it was an upgrade over the previous LG HG2 cells but still not up to the demands for some tools. An engineering balance but they just didn’t make quite the best choices all things considered. They moved to a newer Samsung cell in the 5Ah packs which is much more capable with respectable capacity, so I expect those to do well as long as they aren’t run down to the minimum before charging (still no balancing). I had several of the old 18V 5Ah and 8Ah packs die like this, too, but currently have had no issues with the various HO packs.
I guess time will tell – haven’t heard anything bad yet – if the two Forge designs will be better here, but I expect so. Meanwhile I think they’ll just continue to let customers hang out to dry with the poorer pack/charger designs that they’ve done for so long. For what they charge and for as little as the design and components would cost to implement, they should certainly improve the systems, imho. Oughta be embarrassing but I think they’re making too much money to be embarrassed.
I talked to a really knowledgeable service tech a couple years ago and he eventually got me in touch with someone at Milwaukee…basically they know the issues aren’t have no plans to fully address it at present, relying on a supportive warranty. So save your receipts and use the oldest ones first/most.
Farkleberry
I was looking up weights for HO 12.0 battery to compare 2 of them vs 1 MX and was pretty concerned by the reviews. Kudos to Milwaukee for not filtering their reviews like so many others.
444 reviews at 2.2 out of 5 stars.
Lots of reports of nearly new batteries failing to charge with minimal use, some smoking, etc.
Is this a problem with other Milwaukee batteries?
Dennis
For the person that asked if you can increase the voltage of each individual cell within the battery.
The voltage is dependent on the materials used in the cell chemistry. 3.7V is typical for Lithium chemistries. Similarly, 1.2V is typical for nickel-cadmium (NiCd), 1.2V for nickel-metal hydride (NiMh), 1.5V for alkaline batteries, and 2V for lead-acid.
I am not really getting the whole kindergarten thing. Battery cells in series increase overall battery circuit voltage. Battery cells in parallel increase overall Battery circuit amperage.
Adam
On a group forum, someone claimed that a Milwaukee rep (at an actual hardware shop), said that the 12ah Forge will replace the existing 12ah, as well as the 8ah Forge, due to cell balancing issues with those batteries.
I guess I’m undecided weather this would be true or not. While I know many have had issues, mine have been relatively minor. The 6ah Forge didn’t replace the 6ah HO, but does that have to do with actual build costs. If the 12ah Forge was similar in build cost along with fewer warranty claims, I could understand discontinuing the 12ah HO.
Jason M
I think you’re correct but not due to issues just more duplication in batteries for distributors to carry and offer customers
Stuart
I can’t go by what reps say, as I’ve heard inaccuracies from various brands’ sales reps at Home Depot or Woodworking Shows.
It’s definitely possible Milwaukee will be replacing all of their High Output batteries with tabless, or even just the higher capacity packs.
Cell balancing could be a reason, but eliminating redundancy would also help avoid confusion among users.
Nathan
Interesting bits but what I got out of it was as follows
6.0ah forge is pouch cell. I thought Milwaukee said they weren’t going to get into pouch cell and all forge was going to be tab less.
Meanwhile I took have heard people complain about the larger Milwaukee batteries not maintaining cell group balance. Also echo and other ope too. Shows up as fresh off a rapid charge as not getting all the capacity. And shows up in tool use as significant run time loss. (Again loss of capacity). Solution is typically put on a slow charge for hours. Not heard of this affecting DeWalt or Makita though.
Stuart
Forge 6Ah is pouch. 12Ah will be tabless.
Forge isn’t about any specific battery technology.
Clown Bombadil
You forgot the OG V28 packs.
Stuart
With the discussion centered around M18 Forge, V28/M28, M4, M12, and Redlithium USB are outside the scope of this post.
Dave
Milwaukee promised a cordless snowblower last year and still havn’t delivered, I’m thinking the 12ah forge batteries would be a perfect partner for this. Here’s hoping!
Stuart
They made no promises or official announcements.
They provided a hint about what they’re working on. And that was 2 years ago, not 1.
Jason M
Sounds kinda like a promise to me:
‘Shane Moll, Milwaukee’s President of Power Tools, encouragingly pressed Richman – “what year was that, Steve? What year is it launching?” to which Richman replied:
Next year, 2023.’
A W
The two straws parallel and in series made sense to me. The “you are weightless” scenarios made me think of floating in a zero g environment (outer space, orbit, or a zero g parabola in an airplane), in which case the weight of the box is irrelevant.
I don’t necessarily know a better way to teach electrical concepts, but it took me half a minute to realize we were in the “assume a penguin is a circular cylinder” type of hypotheticals.
Ken Kuhlman
I can tell you one tool that needs the Forge 12ah battery is the Superhawg with the 4-5/8” self feed auger bit (48-25-4621). Our Docks and Piers department has been using air powered tools to make countersunk holes into piles. So I had our department buy a superhawg to try and replace that air setup. It works but it really taxes even the 12ah HO battery. We are waiting impatiently to buy three Forge 12ah and the new Dual Bay Supercharger in hopes that they can run that tool continuously for how long it takes to prep out all the poles. And probably more 4-5/8” bits so they can keep the bits sharp.
Ken Kuhlman
Another system that really needs Forge technology is M12. Forge batteries could possibly make M12 much closer to 18V. And there are tools on M12 that need more powerful batteries like the circular saw, the Fuel bandsaw, the 3” cutoff saw and the Fuel drill. I know they have the newer High Output batteries but they aren’t really because they can’t fit 21600 cells into the grip, so they are just the highest discharging 18650 cells they could find. So if they could make tabless 18650 or combo of 18650 in the grip and 21600 in the base that would be cool.
German Sanchez
With the new tabless cells running cooler, I’m excited to see how they will perform on the M18 Fuel 9″ cut off saw. Currently it overheats High Output 12.0AH and 8.0AH batteries.
As far as new tools that will be released I think Milwaukee will update the rear handle 7-1/4″ circular saw( given that they just released updated 6-1/2″ and 5-3/8″ fuel saws)