Power tool brands might make their own battery packs, but they don’t make their own batteries. Panasonic might be the only exception.
I spent the past two hours or so disassembling 18V 3.0Ah and 4.0Ah battery packs and examining datasheets, at least those I could find online.
All major power tool brands build their 18V (or 18V-class) battery packs with (5) or (10) 18650-size rechargeable Li-ion cells.
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Bosch, Milwaukee, and Hitachi all use Samsung INR cells, Dewalt uses what appear to be Sanyo cells, and Makita uses what appear to be Sony cells. I haven’t taken a look at other battery packs yet.
A lot of power tool brands use the highest performance Li-ion cells available, although not necessarily the highest capacity ones, at least not yet. I have not disassembled other brands’ battery packs yet, but I anticipate that homeowner and DIY-grade brands use lower performance cells.
This should not come as a surprise to anyone, as there aren’t any good reasons why power tool brands would not use off-the-shelf Li-ion cells manufactured by major battery suppliers and OEMs. Even so, this isn’t something that most power tool users ever really think about.
While I can’t speak for power tool brands’ product managers and engineers, these are likely some the more significant factors that determine which batteries brand’s select to build their battery packs with:
Cost. When you’re talking about 5 or 10 battery cells per battery pack and tens of thousands of battery packs per year – if not more, cost is a very important consideration.
A product engineer or manager for a homeowner brand will not select a top-dollar Li-ion cell for their battery packs; they will select the cells which meet or exceed the needs of their tools. Cost is perhaps a more important factor for lower-cost tool makers than higher-end brands. It’s not feasible to sell a cordless tool kit for $65 if the battery costs $50 to manufacture.
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Maximum discharge rate. One brand’s latest 18V battery packs are built with cells advertised as having a 20A max discharge rate (22A on paper), and their previous battery packs were built with cells rated with a 25A max discharge rate (23A on paper).
A homeowner brand will not equip their tools with Li-ion batteries rated for 20A+ max discharge rates, and pro-grade brands will not equip their tools with cells rated much lower than that.
As a reference reminder, a battery with a 2.0Ah rated capacity can deliver a 2A discharge rate for 1 hour. Thus, a 20A discharge rate would deplete the battery charge in 6 minutes.
When is the last time you saw a consumer-grade cordless rotary hammer? Angle grinder? Band saw? Consumer-grade cordless tools don’t have the same power requirements as pro-grade tools, and so they don’t require top-dollar battery cells that can deliver the highest maximum discharge rate.
Minimum operating temperature, or rather minimum operating temperature and battery performance at those temperatures. The best rechargeable Li-ion batteries I have seen thus far can deliver 60% of their rated capacities at -4°F, and 80% at 32°F at a 10A discharge rate. A 10A discharge rate would deplete a 2.0Ah battery in 12 minutes at room temperature (100% capacity).
Battery packs that probably won’t be used outdoors in all weather conditions don’t need cells with good cold weather performance.
Life cycle. Samsung’s recent INR batteries maintain 60% or greater charge capacity after 250 charge cycles. More life cycles means longer usability and less frequent replacement schedule.
Minimum/standard capacity. A 2.0Ah battery won’t necessarily deliver 2.0Ah charge capacity under load. 2.0Ah is the nominal capacity, but during high drain discharge, the actual capacity might drop.
Charging time. Higher performance batteries can usually be charged at higher rates, although active cooling is required to achieve the maximum charging rate.
There are of course a lot of other factors involved in selecting battery cells, but it seems that these are the 5 most significant ones that separate cells suitable for homeowner-grade power tools and those suitable for pro-grade tools.
Although power tool brands aren’t responsible for a lot of what they boast, a lot of engineering does go into battery pack design.
For instance, Dewalt’s 20V Max 2.0Ah battery pack is built with a rather sizable aluminum heatsink, and Milwaukee’s M18 battery pack looks to have the most built-in electronics.
Samsung, Sanyo, and other battery manufacturers are constantly working to develop new and better battery technologies. Except in a few cases, their off-the-shelf batteries are accessible to any and all power tool brands. In other words, if one brand came out with 3.0Ah compact and 6.0Ah extra capacity battery packs today, all others could follow within a reasonable amount of time.
James C
Stu, looking at the bigger picture, how much do you think power tool battery offerings (consisting of 18560 cells) are driven by the laptop computer industry? Looking at market factors, I wonder how feasible it would be for a power tool company to source cells from an OEM that wasn’t already invested with those cells in laptops.
Stuart
There’s no way to tell for sure without looking at brands’ internal R&D projects, but I don’t think there’s a lot of direct connection.
Performance wise, laptop and consumer device batteries are not designed for high drain discharge. Laptops, even those with battery packs built from 18650 cells, and consumer electronic devices benefit from high density low discharge batteries. Power tools benefit from higher density batteries as well, but usage habits are very different.
With continuous use, a laptop battery will last 6-12 hours depending on its size and engineering. With continuous use under load, power tool batteries don’t last very long.
Laptops are designed to sip energy. Early laptops had higher power demands, but the push towards low consumption isn’t anything new. Every component in a laptop, from processor to display, is designed for high efficiency and lower current draw. Power tools, especially those hailed as “corded tool replacements” gulp energy.
According to Apple, their 4th generation iPad has a 42.5Whr (watt-hour) LiPo battery. Lithium polymer batteries are different than Lithium-ion, but I’ll make a comparison anyways. The Dewalt 2.0Ah battery pack in front of me has a 40Whr power rating, and the Milwaukee 4.0Ah battery pack has a 72Whr rating. That iPad battery is designed to last “up to 10 hours” in use. It is NOT designed to be discharged at anywhere near the rate as the Li-ion cells power tool brands use.
Looking at the big picture, it’s tough to know what is influencing battery technology research and development for certain, but the push for electric vehicles might also be a factor.
In recent years the push has been towards thinner and lighter laptops, which means custom battery form factors, and so current and even recent 18650 research and development might not be at all tied into the laptop industry.
joe
True man, if a hacker decides to use “sipping” type batteries in their flashlights, the LED (or other electronic part) might probably burn before the battery does. It would not be business wise decision for companies to give two battery packs – “sipping” for flash lights that can give you lots of hours and “gulping” ones that can give you the most power in a heart beat.
Having said that, those that like to hack can actually take “sipping” batteries and put them in their tool flashlights to make them shine longer before needing a recharge.
I have actually been thinking of using some “sipping” batteries for my dewalt flashlight to see how long it will run before needing a recharge. Have not had time to do this but giving if the electronics are smart enough to charge those cells, i’m sure I can get 12 hrs or more continuous…that is if the LED can take those hours. But mostly I would be worried about the electronics not being designed to take the heat for 12hrs straight. Or maybe that can handle it….one just needs to do some testing 🙂
Stuart
Well, it depends on the LED flashlight. Higher power LED flashlights could destroy low-drain Li-ion battery packs.
Batteries designed for low-drain applications might have the same power capacity as high-drain batteries, but they might not be able to charge as fast and cannot be used as drop-in replacements for high-drain batteries.
You can often swap a low-drain battery with a high-drain battery, but the reverse is NOT true.
Power drain is dependent on tool circuitry and power draw, not on the battery. i.e. a motor or LED will draw as much current as it can unless regulation circuitry controls the power flow. A circuit designed to work with higher drain batteries might not work with low drain batteries. If it does, the low drain battery will be subject to overheating, bursting, or catastrophic failure.
A flashlight designed to deplete a 2.0Ah battery pack in 4 hours can certainly endure lower power settings where it can run for 12 hours.
A battery that can deliver a maximum discharge rate of 20A can be discharged at lower rates just as well as lower performance batteries.
For instance, a battery with 20A max discharge rate can deliver 500mAh of current just as well as a battery with a 2.0A max discharge rate. But, in higher performance applications, such as when 5A current draw is needed, the higher drain battery can be used and the lower drain battery cannot.
Let’s say you take the batteries out of a Black & Decker 20V Max battery pack and swap them into a Dewalt battery pack. You then connect the battery pack to a Dewalt rotary hammer or other heavy duty tool. The cells from the B&D pack would probably overheat and explode. If you took the batteries out of a Dewalt battery pack and swapped them into a Black & Decker battery pack, everything should work fine without issue.
joe
Very true, but the way I see it is that the circuitry is not made by the manufacturer…they are very tolerable because they don’t just manufacture things for one specific area.
One just needs to dig deeper, who made the capacitors, resistors, transistors, etc…most manufacture make those to be “universal”…in effect, none of them are only made to only work with 5v alone…they can handle 2v-10v because it’s more profitable that way than just make 8 different versions of them…if you get my point.
For an example the wall outlet in the USA is 120V AC but they can work with 108V AC up to 130V AC…don’t quote me on this, but i’m 100% sure that 15V up or down, the electronic can handle it.
But you are correct in theory…I just don’t believe engineers not being fruitful.
Something also to think about is that the tool batteries could last longer if the user can handle more hours of charging…the batteries are not made to be charged for 30 minutes…look in the spec sheets and you see they require hours to charge to get the most out of them. Imo.
I believe that I will always get longer run times with batteries on a flash light than any tool 🙂
Stuart
Every few years when I build a new computer for myself or a family member, I inevitably come across component reviews that discuss things like PCB thickness, large capacitor brands and countries of origin, and things like that. For motherboards, power supplies, and other such computer components and electronic equipment, these things make a difference.
I *could* look at other components incorporated into power tools, but how many power tools fail due to blown caps?
If (or when) I start breaking down power tools further, I’ll start looking at things like drill chucks and motors before I look at caps and resistors.
Rapid battery charging does reduce battery lifetime, but possibly not by a significant amount. For users that charge their batteries very frequently, a faster charging time with lower battery life is more favorable than a slower charging time with longer life. With slow chargers, a user might need to purchase an additional battery upfront. With faster chargers, a user might need to purchase a new battery sooner. In the long run, it’s perhaps more economical – not to mention more convenient – for pro-grade tools to come with quick chargers.
fred
Even Henry Ford did not make everything he needed at the River Rouge Plant. It makes sense to “stick to your knitting” – doing what you do best and outsource components that are more efficiently made by others. This post is interesting even though the end consumer has no say in what cells go into their tools. With aftermarket battery rebuilders springing up – knowing the specs of the original cells might make intelligent questioning possible if you decide to go that route – but by the time you are in the market for a rebuild maybe the OEM cell will no longer be available.
jesse
I hope I live to see the day that rechargeable tool batteries of a given voltage are as interchangeable as today’s conventional alkaline batteries – AA, C, D, 9V, etc. Standardization is a wonderful thing. Not likely though.
Craig H
I agree! I was very happy to see that Panasonic moved to standard size AAA NiMH batteries for their cordless telephone handsets.
Steve Cox
The Craftsman C3 use Samsung.
Marco
Not sure what Metabo uses, none of my batteries have died yet, but I do know instead of china like most labels on batteries, their made in Hungry or Austria. The chargers are fantastic at cooling hot batteries as well. Metabo’s batteries were one of the main reasons why I got into there tool line.
Monte
The Metabo cells are made in cooperation with Sanyo
joe
A little OT: Also you have to wonder if “made in the USA” is only a myth. Is the metal that is made from acquired from USA soil? Is the mold the metal is used to mold a toll made in the USA? Are the machines to mold the tool made in the USA?
I don’t believe just because it has a USA label is good quality…it is mostly made with “pro-grade” parts (parts that last longer and are more expensive) that your nickel and dime part.
I took a part a USA made electric paint gun and it turned out that most (if not all) of it’s parts are made elsewhere.
I am not a fan of those that only label good tools as made in the USA…i would rather take away the USA label and focus on th actual parts.
http://www.dslreports.com/forum/r28815736-Electric-paint-sprayer-made-in-the-USA.yes-USA-
Garrick
Off topic a bit… I know in Canada that “made in Canada” means at least 50% of the cost of a product must be Canadian. A can of oysters from China is labeled “made in Canada” when the can is from Canada and costs more than the Chinese oysters.
cody Robertson
Hilti also uses sony battery cells
matt
I am betting Hiliti no longer use’s sony cell’s. Doesn’t panasonic own the line now.
cody Robertson
Ridgid and ryobi use Samsung battery cells
cody Robertson
Porter Cable 18volt battery uses Samsung cells
J Marsh
For porter cable it’s sanyo in their higher end tools (IE) not the big kit. UR18650WX 1500mah pure imr in the better drill and impact gun and the cheaper set has Samsung inr18650 13b 1300mah
cody Robertson
Black and Decker 20volt and porter cable 20volt use Sanyo cells
cody Robertson
Stuart hitachi’s 12volt uses Samsung battery cells but their 18volt batteries uses Sanyo cells
Stuart
The Hitachi 18V 3.0Ah pack I opened up yesterday was built with Samsung cells.
fred
Maybe some of the tool manufacturers have a bid spec and competitively bid out their batteries in batches.
cody Robertson
That’s weird my hitachi 18volt 1.5ah batteries are Sanyo
Dave L
Be aware that the cheaper tools (generally made in China) don’t come with batteries that have thermal overload protection-a thermal fuse-built in.
David
Just so we’re clear, the 18650 denotes the SIZE of the battery, not the chemistry. 18 mm in diameter and 65mm long.
Batteries is an area that I’ve researched a lot recently in building a battery pack for an electric moped. I ended up purchasing used laptop batteries from eBay, testing them, using the good ones and recycling the bad.
An example of differing chemistry is Sony’s 18650 line. They have both US18650 and US18650GR. The GR denotes graphite in the anode, which allows for a higher discharge rate of around 2C (4.4A @ 2200mAh) max but a higher minimum voltage. Put enough of those in parallel and you can have whatever amperage you want.
So if the “pro” batteries are using 10 18650 Li-ions that have a capacity of 2200mAh, they can discharge comfortably at a constant rate of 2 to 4C. If you configure the batteries in groups of two and 5 series (5S2P) you’ll have a battery pack that can deliver A burst of 20 Amps at 18v easily.
The hobbyist and makers have known for a while that the best tool batteries are the old Dewalt 36v packs. The chemistry they used was A123’s LiFePO4. It has a higher discharge rate compared to li-ion, is incredibly stable (low chance of thermal runaway) and can have more charge cycles than standard li-ion cells. A123 went out of business recently and was purchased by a Chinese manufacturer, so I’m not sure if Dewalt is still using these cells or not.
But that’s my two cents for what it’s worth.
Stuart
I actually prefer NiMH for hobbyist use (such as robotics), as such battery packs require far less attention and care. LiPo packs are smaller, lighter, and more energy dense, but are more volatile.
You’re right in pointing out that each brand offers many different battery chemistries with the 18650 form factor. Sanyo cells in Dewalt packs won’t be the same as Sanyo cells in Black & Decker packs.
The Samsung cells used in Milwaukee packs are capable of a lot higher than 2C discharge rates. The 1.5Ah cell has a 25A advertised rating (23A in the spec sheet), and the 2.0Ah cell has a 20A rating (22A in spec sheet). So that’s what, >15C for the 1.5Ah cell and >10C for the 2.0Ah cell. The performance vs. temperature plots in the 2.0Ah cells’ datasheets (Samsung INR18650-20R), was done with a 10A discharge rate, which means the batteries should perform comfortable at a 5C rate. At the 5C discharge rate, there is a slight drop in capacity (less than 2.5%). At a 5C rate, a 2.0Ah battery pack will last 12-minutes.
Not a lot of users are going to use compact battery packs for applications where they have to reach for a freshly charged pack several times an hour. Since extended capacity battery packs have multiple pairs of cells in parallel, the effective discharge rate would be halved. Similarly, the maximum discharge rate for the pack would be higher, which is why some brands’ higher capacity battery packs provide greater runtime AND power compared to compact packs.
With modern packs, a burst of 20A at 18V is easy, but – especially with higher capacity battery packs – sustained rates of 20A are easily feasible.
Larson
I remember seeing this post a few years ago:
http://dewaltownersgroup.com/index.php?/topic/600-dewalt-changed-cells-in-36v-batteries/
Such a bummer, so many projects from those. Heard they had a pretty bad breakup with A123
quad shop
As far as I know the 18v dewalt li-ion is still A123’s chemistry but the newer 20v is not would love for someone to prove this as I have that system. Maybe I just need to get a tamper resistant t-15 flex and see for myself.
quad shop
Torx is it just me or does auto correct actually make it harder to write stuff correctly
Stuart
You’ll need a tamper proof T10, not a T15, at least for the 20V Max packs.
Alan S. Blue
The automotive fuel cells appear to be on track for 2015 … what’s the status on fuel cells for use in power tools? Probably a question for Panasonic, Sanyo, Energizer as opposed to the tool companies, but interested to hear about progress.
fred
ITW-Paslode used to call their fuel canisters fuel cells.
But seriously will we likely have a portable drill with a hydrogen cylinder – or metal hydride storage canister feeding a fuel cell that drips water out the bottom of the pistol grip?
Alan S. Blue
There’s a variety of types of fuel cells for exactly the same reason there’s a variety of types of battery though – they’re the same thing chemically.
As an example, a methanol fuel cell would mean you’re filling a tank with fuel and converting it to a little steam. A tank the size of the larger battery packs should run for a long time.
fred
Thanks Alan
I was thinking more about the PEM fuels cells that folks seem to be working on for automobiles and forgot about the nascent work on the DMFC variant. I guess its partly about energy density – and methanol obviously packs more in than hydrogen. Now if researchers can get a SOFC to run directly on gasoline , work at a much lower temperature, have a competitive price point and have a form factor to fit in a car (or dare we think a power tool) – then we could take advantage of gasoline’s even higher energy density.
Robert
I’ve said for years that the performance a power tool battery is more important than the performance of the tool itself. Panasonic is arguably more of a battery manufacturer than a tool maker. While many of their tools perform to excellent specs, they get top dollar because they simply make excellent batteries.
I can see why many manufacturers don’t attempt to make their own batteries. It’s an entirely different and continually changing science. And make no mistake, it is a science. It’s a similar philisophy to why airplane manufacturers don’t also produce jet engines. If the tool manufacturers aren’t prepared to jump into battery making head first, they’re better off leaving it alone. The battery market alone is competitive.
Panasonic is in a unique and experienced position. I would expect the other tool companies to take a huge fiscal hit in the process of just getting caught up.
Chris Fyfe
Good post on an area that’s a total minefield . I’m currently in charger hell . I have two Metabo chargers ( drill & SDS hammer drill ) , Hilti ( regular cordless drill & impact driver ) , and a Milwaukee M12/M18 charger ( recip saw /jig saw /work lite/angle drill/minirecip/powerport , jacket ) .
Much as some of Bosch’s 12 volt offerings look nice , I just don’t want to add another system . Not to mention , I have a Jones for some Festool stuff . Stop the insanity !
What a PITA !
Chris
Eric
Great post. Thought I’d chime in with some battery IDs from my cheap cordless tools.
Skil 18V pack > 5X INR18650-13P (1300mAh 10A continuous)
Black&Decker 12V pack > 3X Sanyo UR18650S (1100mAh 10A continuous)
Canadian Tire Mastercraft 12V pack > 3X Sanyo UR18650S (1100mAh 10A continuous)
Eric
INR18650-13P is Samsung
The Right Rev
“For instance, Dewalt’s 20V Max 2.0Ah battery pack is built with a rather sizable aluminum heatsink, and Milwaukee’s M18 battery pack looks to have the most built-in electronics.”
– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
This preponderance of electronics not previously seen in cordless tool that is present in the Milwaukee fuel/M18 series is a result of a marked change in their engineering and design ‘philosophy’. I’d be willing to bet that in the near future, most of the mid to high end consumer grade tool makers will follow suit. What they have done, without getting too technical, is they have done away with a beefy trigger switch designed to take the current, heat, and abuse of prior units and replaced it with a sort of drive by wire system. Instead of the switch itself doing the job of metering the current to the motor, which required some very robust components and construction, the switch is hooked up to a micro controller and a series of mosfets. It is the controller that does the job of determining how much power is being requested, how much the battery can supply, what the motor can makes etc. The mosfet does the heavy lifting of actually switching the current. By building the tool this way, it makes it almost impossible to over work the motor by applying full power when there’s no way for the tool to move. Current will simply be reduced or cut off, saving wear and tear on the unit as a whole, but more importantly, to the manufacturer anyway, reducing the likelyhood and frequency of warranty claims from burnt out tools. nother benefir the the company is that knowing the defined upper limit of power that can be applied, smaller, less robust components can be used in the tool, making it lighter, a selling point for sure, cheaper to manufacture, and probably longer lasting. Personally, though, I much prefer the older system. I like to use my hands and my nose to feel and smell if I am overheating a tool.
I hope this has shed some light on this subject.
Chris Dowling
Have you examined current batteries and the cells they are using? ive opened up a few of my dead makita batteries and have found sony (2009ish) and samsung (2012).
I’m looking at a bulk order of generic makita batteries and just deciding on which cells to get. samsung, sanyo, lg have been offered so far.
chris blair
Do u know the exact numbers on the 18650s that are in milwaukkee 18 volt 4 ah and 5 ah batteries. I have the new craftsman xcp 4ah batteries and am very impressed with the power. I took one apart to see what was in it and they are of course the Samsung 18650s. but they are inr18650-20q which I think from my research are 2000 mah and 15 amp cont. draw. I was thinking about replacing all those with the Samsung inr18650 25r. they have 2500 mah and 20 amp cont. current draw. I definitely would appreciate it if someone could tell me the exact 18650 that’s in the Milwaukee. thanks.
Stuart
If I recall correctly, they’re INR series with 20 to 25A peak current rating, depending on size.
Tyler
I have a hard time envisioning power tools powered by fuel cells, if only based on the internal heat generated, which can be upwards of 1000 degrees Fahrenheit, but I’ve heard of research on fuel cells that produce half that. The cordless tool user is concerned with convenience, cost, and efficiency. If we don’t like the price of the result, the alternative is to become a corded tool user, which is what I’ve done lately, mostly without regret. The cord is always there, but so is the power.
Tool companies aren’t going to become battery companies, and Panasonic looks like a bit of a relic. I was barely aware that they made power tools.
Most likely, tool batteries will follow the model of computer processors, but much more slowly, with incremental advances backed by new logos and ad campaigns.
I’ve looked into LiPo (lithium polymer) packs, and they seem to be extremely temperamental regarding overcharging and over-discharging, as well as having a lower service life than other cells I’ve looked at, around 500 cycles. (Not sure how this compares in use to cordless tool batteries.) These technical issues can be managed with electronics, but not cured. They can also be pressure sensitive, and I’d speculate shock sensitive also.
A few questions come to mind: is discharge rate really additive among cells? My first assumption when learning about C-rate was that it was fixed at or near the value for the lowest cell, but someone above, possibly blogmaster, has alluded to it being cumulative (when wired in parallel?)
Does anyone know if tool companies even make their own motors? It makes me wonder how many of a brand’s components can be described as truly in-house.
edward yeo
Super capacitors is the way forward, rechargeable a million times.
Ray Smith
Hello Toolguyd,
I am looking to power a laptop and a separate 5v 1a wifi receiver. I will be using a step down from 12v to 5v 2a (which will take some power itself) for the wifi device and a manufacturers car charger specifically built for the laptop at 16.9v 1.7a. Can you suggest and suitable battery for this purpose assuming I would like about 6hrs of use.
Thank you in advance
Stuart
Sorry, I have no idea what to recommend for your particular application.
BC
Does anyone know who makes Milwaukee M18 9.0 batteries. I am wondering if they are being made in China?