I’ve been asked a tough question – how does the new Dewalt 20V Max 10Ah battery compare to their FlexVolt 9Ah battery?
To start, you can buy a 2-pack of 9Ah batteries for $299 on Amazon, and some retailers have it priced at $329. The Dewalt 20V Max 10Ah battery 2-pack is priced at $349 at Tool Nut.
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With these two batteries similarly spec’ed at 10Ah vs. 9Ah, how do they compare?
Dewalt 20V Max 10Ah Battery (DCB210)
I have not yet tested or even handled the new 10Ah battery, but it’s fair to assume that it’s engineered with 21700-sized Li-ion cells.
This is a 10-cell battery built with Li-ion cells presumably rated at 5.0Ah each. The cells are arranged in a 5S2P configuration, which means that you have 2 rows of 5 battery cells arranged in series.
Each battery cell has a 3.6V nominal voltage, or 4.0V Max voltage. So, 5x 4.0 = 20V Max. With two rows of cells arranged in parallel, the charge capacity adds up, so you have 5.0Ah x 2 = 10.0Ah.
If you need help visualizing this, take your two hands and put them together, with open palms facing and left and right fingers touching each other. You have 2 groupings of 5 fingers in a 5S2P configuration. Now, make two fists and stack them, one on top of the other. Your knuckles should line up in a single-file row. Excluding the thumb, this would be an 8S1P configuration.
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Dewalt FlexVolt 9Ah Battery (DCB609)
Dewalt’s 9Ah battery, also presumably built with 21700-sized Li-ion cells, has 15 cells.
When connected to a FlexVolt 60V Max cordless power tool, those 15 Li-ion cells are switched to a 15S1P configuration, where you have 4.0V x 15 = 60V Max. The charge capacity is not additive in a 1P configuration, and so it would be whatever the individual cells are rated at, or 3.0Ah for this configuration.
In parallel mode for use with a 20V Max cordless power tool, the same 15 cells are switched to a 5S3P configuration. 5×3 = the same 15 cells as in serial mode.
In 5S3P mode, 4.0V x 6 = 20V Max, and 3 x 3.0Ah = 9.0Ah.
Theoretical Differences
Generally, Dewalt’s 20V Max cordless power tools are designed around the power delivery capabilities of 20V Max batteries. In other words, the 10Ah battery and FlexVolt 9Ah battery should in theory deliver comparable performance but with just a proportional difference in runtime. After all, the same tools are also designed to be powered by Dewalt’s full spectrum of battery sizes, including their 1.5Ah to 5.0Ah batteries (and FlexVolt 6Ah) engineered with 18650 Li-ion cells.
Let’s remove that consideration for a moment. For the sake of this discussion there exists a hypothetical Dewalt 20V Max tool that can draw increasingly high levels of current from any connected battery.
We’re also speaking about the FlexVolt battery in parallel 20V Max-compatible mode exclusively.
Alright, so we have the 10Ah battery with its 5S2P configuration of 5.0Ah cells, and the 9Ah battery with its 5S3P configuration of 3.0Ah cells.
Let’s change things a bit. Instead of the two batteries being engineered with different Li-ion cells, let’s say that they both featured the same Li-ion cells, either 3.0Ah or 5.0Ah, it doesn’t matter.
With all things being equal, a 5S3P battery can deliver more power than a 5S2P battery.
Imagine that there are 5 people with identical strength and endurance, and they are split into two groups of 2 and 3. When faced with light work, the two groups will perform their tasks with comparable effectiveness. When faced with medium-duty work, you might start to see some differences. But with heavier work, you’ll see an increasing performance gap between the two groups as you approach or surpass the limit of what a group of 2 such people can do.
When composed of identically-capable members, a team of 3 can outperform a team of 2.
The tricky part here is 20V Max tools are designed to be powered by 5S2P and even 5S1P (compact 5-cell) batteries. And so, the real-world differences likely come down to proportional differences in runtime.
But wait, there’s more to consider. What we were talking about just now involves imagining that both batteries were engineered with the same Li-ion cells, but they’re not. The 10Ah battery is engineered with 5.0Ah cells, while the 9Ah battery is engineered with 3.0Ah cells.
Generally, and I say this in case there are ever exceptions, when considering cylindrical batteries of comparable size and technologies, and within the same or similar product families, higher capacity batteries with higher energy densities will have lower constant discharge current ratings. Battery cooling and heat dissipation come into play here as well.
There’s a common trope where a smaller guy is fighting a larger guy, and all they have to do is wait for the larger guy to tire themselves out. It’s kind of like this.
We don’t know what lithium ion battery cells are used in the 10Ah or 9Ah batteries right now, so let’s look at two off-the-shelf batteries.
The Samsung INR21700-50E has a 5Ah charge capacity and is rated with a maximum constant discharge current of 9.8A. The Samsung INR21700-30T has a 3Ah charge capacity and is rated with a maximum constant discharge current of 35A.
Let’s say you have a device that runs at 3.6V (the nominal voltage for Li-ion cells of this type) and draws a continuous 9.5A of current. Both of these 3.0Ah and 5.0Ah batteries will be up to the task, and at the end, the higher capacity 5.0Ah battery will likely run quite a bit hotter. Crank up the power demand slightly, and the 5.0Ah battery might exceed its operating conditions if it cannot be cooled fast enough. Cooling is an important part here, because this is greatly influences how much sustained power a battery can deliver.
Brands shifted from 18650 cells to 21700-sized cells for similar reasons. 18650-sized 3.0Ah cells were not quite up to the power delivery capabilities as 1.5Ah to 2.5ah cells. Shifting to 21700 meant that 3.0Ah charge capacity (and higher) were possible with lower charge density, which meant higher maximum continuous current discharge rates and cooler batteries under load.
Dewalt has a new FlexVolt 15Ah battery coming out, and features a different battery configuration than their FlexVolt 9Ah and 12Ah batteries. This is likely because 5.0Ah cells cannot deliver sufficient power in a FlexVolt 60V Max 15S1P configuration.
Batteries with higher energy densities have lower max discharge current specs, and they also often run hotter. At lower demands, the higher charge capacity battery delivers proportionally longer runtime, but at greater demands the lower capacity battery will often have a much higher power and performance ceiling.
Consider, a race between a sprinter and a long distance runner. In slow and long territory, with both runners matching each other’s strides, the long distance runner will last longer. But in hard and fast territory, the long distance runner might get winded and pass out as the sprinter surpasses them.
Okay, so let’s add things up. In theory, a 5S3P (FlexVolt 15 cell in 20V Max mode) battery configuration can deliver more power than a 5S2P battery configuration (20V Max) when using the same exact cylindrical form factor Li-ion cells – 21700-sized in this case.
And, as far as I have seen, a 3.0Ah battery cell can deliver more power than a 5.0Ah cell.
So, in a comparison between a 5S3P battery with 3.0Ah cells and a 5S2P battery with 5.0 cells, you have 15 battery cells capable of greater power deliver compared to 10 battery cells of lower capability.
There is going to be a huge gap between the theoretical capabilities of a FlexVolt 9Ah battery and a 20V Max 10Ah battery.
However, this is all theoretical. Realistically, Dewalt designed and tested the 10Ah battery to match the power needs of 20V Max cordless power tools. The 10Ah battery is smaller and lighter than their FlexVolt 9Ah battery, which also delivering around 11% longer runtime. If the 10Ah battery runs hotter than the brands’ other 20V Max batteries, that could potentially affect things, but I trust that Dewalt knows what they’re doing.
(There are other factors to consider, but it’s best to ignore them for simplicity, such as how heat dissipation might differ in Dewalt’s 15-cell FlexVolt batteries vs. their 10-cell 20V Max batteries.)
It’s difficult to draw conclusions about any of this, which is why I stressed it’s all in theory. In theory, the 9Ah FlexVolt battery looks a lot better when it comes to potential on-paper electrical power capabilities compared to the 10Ah 20V Max battery. However, the engineering around all this means that the 10Ah battery should be capable of delivering the power requirements of any of Dewalt’s 20V Max cordless power tools. As long as what it’s being asked to do falls within its capabilities, do the theoretical performance ceilings matter?
If you’re 6 feet tall, does it matter if a doorway is 7 feet tall or 10 feet tall?
It remains to be seen whether Dewalt’s new 10Ah battery can sufficiently power all of their 20V Max cordless power tools without breaking a sweat, but keeping in mind that their higher performance tools are powered by 15-cell FlexVolt batteries, I don’t feel this to be a major concern.
As an aside, given the specs I’ve seen for 21700-sized 5.0Ah lithium-ion battery cells, it seems that we’ve about reached the limits as to how high of a practical charge capacity can be achieved with this form factor. Some brands are better-rated than Samsung’s INR, such as Panasonic (15A max continuous discharge current), while others are worse, such as LG (~7.3A max continuous discharge current at room temperature).
Which One to Buy?
If you want to save a little money and are okay with a little more size and weight, or if you need FlexVolt tool compatibility, go with the FlexVolt 9.0Ah. If you want a slightly smaller and lighter battery and want a little more runtime from 20V Max cordless power tools, go with the 10.0Ah battery.
In 20V Max applications, the 10Ah *should* deliver a little longer runtime and in a smaller package than the FlexVolt 9.0Ah battery.
If you don’t want to be an early adopter, wait for others to put the 10Ah battery through its paces. I would caution against getting hung up on theoretical limits.
Jared
I need more pictures. 😄
Interesting read. Were I to boil it down to a couple lines, the conclusion then is:
The 9.0ah Flexvolt battery is theoretically capable of delivering more power in 20v max configuration. However, the 10ah has a little more capacity and should be capable of delivering the necessary power for any 20v tool.
Good information to bear in mind.
Stuart
The FlexVolt 9Ah battery can in theory deliver more power than the 20V Max 10Ah battery in 20V Max power tool applications, but are there any 20V Max tools that can utilize this theoretical headroom?
I would assume there aren’t – Dewalt has much more to lose than to gain if they were to launch an under-performing 10Ah battery – which is what makes this an academic comparison about theoretical capabilities.
Jared
Good point – that is a better way to phrase it because the point is that there shouldn’t be any 20v tools that can stress the 10ah batteries limits.
That makes sense too. 20v max tools are intended to work with battery packs all the way down to 1.5ah. Those tiny packs might limit performance in high draw applications (like if you tried to mow your lawn 😄), but it seems safe to assume Dewalt designed this 10ah pack with more than sufficient “headroom”, It would be a bad look for a high capacity pack to be throttling performance.
MM
I’m sure we’ll see some real-world testing once these batteries become more widely available. It would be interesting to take a high-power-demand tool like a circular saw or a grinder (or the mower!) and do a side-by-side comparison. Work both batteries hard and see which runs longer or if there is any noticeable difference in power. I can say for certain that my 20V max flathead grinder is noticeably more powerful when running on a 9ah flexvolt batt compared to 4, 5, and 6ah 20V max batts. It’s not just runtime, the difference in power is noticeable. Alas I don’t have an 8 or 10ah 20V max to compare with.
Mr. Creek
20V that can use the extra head space, Flexvolt Advantage.
Jeremy Solsbery
Have you seen the new Dewalt 20v sawzall? DCS382B Didn’t know this even existed
Big Richard
Yes, it is the new entry level compact brushless model. It just came out in the past few months, but it is essentially a yellow version of the Craftsman CMCS350, that has been out for a little over a year.
It actually seems faster at light cutting jobs than its bigger brothers with its 3200 SPM, and has much better vibration control than the previous compact reciprocating saws, DCS367/DCS387.
Domdymond
Yes, in tests most dewalt tools take a marginal gain with the flex volt over the xr, especially their higher power demand tools like the xr hammer drill. or most of their saws.
Julian Emmett Turner
Ever hear what kind of cells are in these? It’s been long enough that I expected someone would have done a tear down but I can’t find any. No repair logs, no rebuilds, no autopsies… but there are a WHOLE lot of dead ones.
Yeah, I think they are cooking themselves, which was your concern even though you gave DeWALT the benefit of the doubt.
Stuart
Not yet.
Nobody has been asking for feedback or testing, so I never sought out a test sample.
Online user reviews have been consistently negative.
I’ve seen datasheets for 21700-sized cells with 5Ah capacity, such as Samsung INR21700-50S. While the continuous discharge spec is 25A without and 45A with temperature cut-off, the INR21700-40T cell has 35A and 45A max discharge ratings (without/with temp cut respectively).
A FlexVolt 12Ah battery is going to have 3x rows of 35A max discharge cells, vs 2x rows of 25A max discharge cells for the 10Ah – assuming whatever cells Dewalt uses are comparable to what look to be Samsung’s best.
Samsung also has 3Ah batteries with 35A continuous discharge current.
I would choose Dewalt 20V Max 8Ah or FlexVolt 9Ah or 12Ah over the 10Ah with few exceptions.
The 10Ah doesn’t look as good on-paper, given datasheets for what I believe are the industry’s best 21700 cells prior to tabless electrode advancements, and user reviews – even if they represent a minority of customers who are dissatisfied with this battery – suggest it’s more of a battery for specific tasks than one that should be used with higher demand 20V Max-compatible tools and those designed for higher output batteries.
Big Richard
A large majority of the negative reviews, if not all, are from them being used in the mowers they were kitted with. So while the batteries are not going to be as robust as something like the 9Ah FlexVolt, the mower seems to be an integral factor in their higher than normal failure rate. The prevailing theory is that the mowers can draw unevenly from one battery, taking it below its low voltage threshold causing irreparable damage. Add in the summer heat, and no lithium battery is going to like that.
This next part is pure speculation, but I also would not be surprised if a good deal is from people who are not familiar with lithium battery best practices. I.e a home owner who has never used a battery power tool before, but buys a new cordless mower because it’s the modern choice and they constantly are running the batteries completely dead, partially charging to finish the job, leaving them sit in a hot garage in a dead state for long periods of time, etc.. I’m not trying to victm blame, but I think user error/learning curve is a factor as well. I feel like I see it a lot with other brands as well, and OPE specifically.
I was skeptical on them from the beginning, I have a 2020 pair and 2022 pair, each with weekly use during the growing season and have had no issues yet. Small sample size, I know.
They are great in low draw tools where you want max runtime in the smallest possible package. I take one with me camping and it powers the fan, blower, inflator, speaker, everything for the whole trip. So they do have their place. But for higher draw tools, go for the 9Ah FlexVolt over the 8Ah and 10Ah packs.
Julian Emmett Turner
Thanks. Well, I went ahead and opened up my bad one and can confirm it has Samsung INR21700-50S cells. It was much easier to get a look at the cell wrappers than any other tool pack I’ve ever torn into because the bottom plate is only held on by adhesive mica sheets on the front and back.
One segment measures 3.6v while the rest are 4v so there appears to be a balance issue. What typically happens is the mower stops working while one 10Ah battery reads full and the other still reads one or two bars… so neither reads fully dead. It was behaving like this from the start since I bought them used (improperly described as new). I have an 8Ah pack that came with my PowerDetect hammer drill so my options are to find a deal on another 8Ah XR pack or to find an even better deal on 2x 9Ah FlexVolts. I have no 60V Max tools so I’m leaning toward the 8Ah option. In the mean time I switch to 2x 5Ah XR and keep mowing.
I saw where Big Richard said DeWALT must have solved the issues with 10Ah batteries since they still sell them with the mowers but I noticed last year that they include 9Ah FlexVolt if you buy from Home Depot and 10Ah XR if you buy from Lowe’s. I’d respond directly but that seems to be the only post of his without a Reply button. :/
Big Richard
@Julian,
The gen II RWD DCMWSP255 was offered with 2x12Ah FlexVolt batteries in the Y2 kit configuration. That was the only model that had that kit option (i.e. the push and FWD models did not have that kit) and it was sold at HD and other retailers. Lowes cannot/does not sell FlexVolt tools or batteries, so that kit option was not an option there. Only the U2 kits that came with the 2x10Ah. So that’s the rationale there.
As I mentioned above though, the new gen III mowers, both push and RWD, are only available in the U2 kits with 2x10Ah batteries, even at HD. I think since there are also 60v models, we will not see the 2x20v kitted with FV batteries. Just my guess.
MM
I don’t believe these batteries are cooking themselves. I have a pair and I’ve used them a lot with high drain tools without any problems. However, I think Big Richard has a very good point about the mowers these batteries were often kitted with. I’ve noticed two issues.
First, the mower constantly drains the batteries if you leave the batts plugged in, to the point that the charger refuses to charge the batteries any more. I explained my experience in more detail on the Toolguyd forum:
https://discuss.toolguyd.com/t/dewalt-mower-10ah-20v-max-pack-shenanigans/3197
Second, the mowers may have a problem which users might confuse with bad batteries. My mower has had very light use, I only use it a handful of times a year to clean up places where my big ZTR won’t fit. However when I went to try to use it this past weekend it was acting odd. The symptoms mimicked low batteries, however batteries were clearly not the problem as the same issue persisted with other batteries including a set of 15ah Flexvolts right off the charger, and I’ve used those 10ah packs on other tools with zero problems. I haven’t had a chance to follow up and troubleshoot exactly what is wrong with the mower but whatever it is behaves like bad batteries, so I could easily see why someone might think the batteries are the culprit.
Big Richard
DeWalt must not see the batteries themselves as the issue either, as they are still pairing the the new gen III 2x20v mowers with the 10Ah batteries. I assume they have alleviated whatever the issue was with the mower.
I’d like to see them paired with the new tabless 8Ah PowerPack batteries, but that would bump the price up a bit and lower the runtime. Those should be able to handle the heat better, and offer more runtime than something like the 5Ah PowerStack.
Julian Emmett Turner
Well, mine definitely cooked itself last week.
I used my BT-C3400 with some alligator clips to the balance leads to bring the imbalanced segment up to the same voltage as the others (4.15v). I wanted to see if the imbalance returned after running it all the way down but I ended up finishing the lawn with some charge remaining… though the pack was still reading lower than my other one: two bars versus three. I fully charged it and it remained balanced though the segment voltage seemed to drop to 4v per cell (from 4.15v).
The next time I mowed it died prematurely. The problematic battery had one bar left and the other had two, but it normally doesn’t stop until both batteries have no bars. I also found that the problematic pack was too hot to hold while the other was just a little warm. These INR21700-50S cells are particularly sensitive to heat but it isn’t supposed to overheat when mowing in the first place. The crazy heat seems to explain the mower’s premature shut off.
I let it cool for several hours before charging. Voltage seemed normal the next morning and I still needed to finish mowing but, yet again, the mower died prematurely. Though the problematic battery was notably warmer, it didn’t have the time to get hot like it did before. This time it seems to have been protecting against over discharge since the imbalance was back with a vengeance.
I didn’t discover the imbalance until after charging again so I can’t say for sure that segment didn’t get over-discharged but it was reading nearly a volt lower than the others after charging. If I’m right, over discharge protection shut off the mower and the crazy heat from days earlier seems to have cooked it. Those two damaged cells have a higher internal resistance causing excessive heat.
In case the imbalance was due to a capacity issue, I decided to use my BT-C3400 to do a refresh cycle on the imbalanced cells. This fully charges and safely discharges 3x to restore full capacity. To make sure it didn’t overheat I set a very low amperage that was going to take over a week (300mA) but a few days later I found it doing a normal 500mA charge instead.
There must have been a power interruption causing it to do a default charge but it was almost done and it didn’t seem to be getting hot so I tried to let it finish overnight. For some reason it wasn’t finished the next morning. When I got back from work it STILL wasn’t finished… and the charger was claiming to have put 16mAH into a 10AH segment! After another day it hit 20AH and I realized voltage had gone up and down a few times. It was never going to reach 4v so I unplugged it. Those cells are gone. They probably overheated surrounding cells too so I don’t think it’s worth replacing those two even if I can order some INR21700-50S.
Goodbye, DCB210. I hardly knew ye.
Alan
Both of my 10ah have now died. The first one began failing within months of purchasing my mower brand new. Dewalt replaced battery under warranty and now 2 years later the other original 10ah has died. I have a ton of Dewalt tools (all stored in my garage with my mower) and the 10ah batteries are the only ones that have ever failed. Dewalt will warranty my battery but they’re out of 10ah and offered to send 2 DCB609 Flexvolt 9ah batteries instead. I will go this route because I have 2 other tools using them and haven’t had any problems. By the way the 10ah batteries were manufactured in 2021 and as plenty of other companies had issues with production during the pandemic I suspect this may have something to do with the poor quality
Julian Emmett Turner
…and by “those cells are gone” I mean they won’t hold their charge even with no load. After finding that I could not quite reach 4v at 500mA charge rate I disconnected them and they dropped to 2.5v in one day with nothing connected. Just sitting there. They’re at the cut-off voltage before I even start!
That only started happening after they overheated in the mower and cooked themselves but, of course, something also caused them to be in the imbalanced state I originally found them in. Past overheating or previous owner’s poor battery handling practices? Not sure.
I’ll be getting another DCB210 or rebuilding this one… hopefully before the HOA complains about the unmowed yard. 🙂 When I do, I’ll be monitoring closely to see what’s really going on with these things!
Bob
It could be the Control Module which you can only buy from Dewalt for around $60.
Big Richard
To summarize why there is a 10Ah 20v when the 9Ah FelxVolt already exists:
The 10Ah is 5 person sedan, while the 9Ah is 5 person midsize SUV with a clas III hitch. Why buy a car when you can buy an SUV that can do more? Because not everybody needs to “do more”, they aren’t going to tow/haul. And the car is 2/3 the size of the SUV.
Prefer one over the other? Great. But that doesn’t mean the other shouldn’t exist. Not to mention FlexVolt is not available everywhere, so a high capacity 20v battery makes sense.
Nathan
I didn’t see this in the article but might have missed it.
Unless you own or plan to own a flex volt tool or a flexvolt advantage tool – then the potential current throughput benefit is not there with any other device. For dewalt tools the power control logic is in the tool so without the bits that know how and when to pull extra current for demand – the extra capacity isn’t useful.
MM
I don’t think that’s necessarily true.
Obviously only something like a Flexvolt Advantage or a Power Detect tool has a built-in feature to upgrade its power when it detects a larger battery, so you’re right you won’t get that kind of a feature simply by using larger batteries in a basic tool that lacks those features.
But tools that draw a lot of power like a circular saw or a grinder run very differently on a small battery versus a larger one. Trying to run an angle grinder or a big rotary hammer on a 1.5 or 2.0 ah battery is a joke, though they work fine for impact drivers and OMTs. In my personal experience tools like grinders and circ saws do perform better with larger batteries. I don’t just mean the runtime, I mean how hard you can work the tool before it starts to bog down. Now clearly there is some limit there–just because a 6ah battery outperforms a 1.5ah doesn’t mean a 10ah or a flexvolt will be any better–but it certainly is possible for larger batteries to help a tool’s power without features like Flexvolt Advantage.
Domdymond
I was under the impression the power management was in the battery.
philip s john
I like the power and compact 20v 10 for
20v grinders and compact light. Can run 2000 lumen for around 10h.
A 9 flex 60v is good balance for 60v tools.
Evadman
Batteries can discharge more then they are rated for, but it shortens the life and runtime. More energy is recoverable from a 5AH battery when pulling 1 amp for 5 hours then pulling 5 amps for 1 hour. This is manifested in runtime, so the 5 amps for 1 hour will be closer to 45 minutes at 5 amps instead.
The biggest power consumer I have personally used in the dewalt line is the different grinders, which I have gotten all of over the course of the last few years. (The different flavors of 60v and 20v). I have used the 1.3ah batteries on the 20v grinders when I had nothing else available; and you get perhaps 30 seconds of work from them. I believe they pull around 1100 to 1300 watts, which would be between 60 to 70 amps. I usually use 6AH flexvolt batteries on the 20v versions, and I get about 5 minutes of heavy grinding; that equates to around 5 amp hours if I am doing my math right.
Long story short, more cells generally means longer run time at the same power usage. So if you have space, the 3AH packs that use 5P2S have more usable power than the the newer 3AH 5P1S compact packs.
Plain grainy
This battery is different from the 10ah 20 volt max in your Dewalt lawnmower?
Big Richard
Nope, same DCB210.
Plain grainy
Ok, thanks! I was thinking it was a new improved model.
Plain grainy
Manufacturers sometimes refine fairly new products. Example: Milwaukee had a cord on their original Packout light/ charger. I noticed that on a YouTube review video from Australia I think. The new refined version has no cord, you plug an extension cord into two prongs at light body. Same as Dewalt’s duel voltage fan, and also the power station. It makes more room in the phone charging compartment, and keeps the extension cord connection off the wet floor. I noticed you can store a 5ah m-18 in the phone compartment, it might even hold a larger battery. I’m assuming the US version was the same as other countries.
X Lu
Literally the reason I take a hard pass on deWalt these days. Far too many options and confusion. Either this article does a poor job of simplifying the highly confusing or it is so confusing it simply can’t be simplified-I think it’s the latter. I believe the 9amp has 11 pct less power and are nearly 17 pct cheaper. That would make it a no brainer if correct.
I’ll stick to m18 3 amp high output and 8/12 amp for the heavy stuff. Simple.
XRH07
Flexvolt 9.0 uses Samsung 30T 21700s. Same cell used in the slim 3.0 and the XR 6.0. All 3 of these packs previously used 20700s from Sanyo but were switched to 21700s sometime in late 2018/early 2019.
XR 10.0 uses Samsung 50S 21700s. So will the new 15 Ah Flexvolt battery.
Big Richard
I believe the slim 3Ah never had the Sanyo NCR20700A cells, it was birthed with the Samsung 30Ts as it first debuted in 2018.
And we still don’t have definitive proof on the 15Ah cell composition. Insider told me 30 18650s, and based on its size it seems plausible. Yes, it could be 15 21700s with massive amounts of cooling tech, but I’m waiting to tear one down myself to be sure.
Let’sGoBrandon
Can you do a story explaining why the 9ah flexvolt weighs the same or slightly more than the 12ah flexvolt ?
Stuart
Same size/form factor battery cells, different energy density. This is similar to how 3Ah, 4Ah, and 5Ah batteries are the same size and (approximate?) weight.
If it helps, think of it as akin to regular AA vs. premium AA battery cells.
Don Julio
Your handle made me lol, LGB!
Mason
One consideration that isn’t huge, but could be important if you’ve ever intent to travel with them by air. You’re allowed to transport an unlimited number of 100 Watt Hour (5AH and below) batteries, but need specific permission from the airline to transport a maximum of two that are bigger
Because of the Flexvolt design, those batteries can have a red plastic cap snapped on to them that for legal purposes separates them into three parallel 60WH batteries that happen to be in the same package, therefore allowing you to transport a theoretically unlimited number of them without engaging in bureaucratic messes. I don’t believe the larger 20v max batteries can do this.
andy
Another perspective based on bench testing the cells. The 9Ah pack can deliver more power AND more capacity above a certain current draw.
The cells in the 10Ah battery drop it to about 9ah capacity and about 150wh delivered when the draw from the pack is 40A (almost 1 hp)
The cells in the 9Ah battery maintain 9ah capacity and about 160wh delivered when the draw from the pack is 60A
X Lu
Which suggests the 9ah batteries are even less expensive ie deliver an additional 10wh of power under draw if the use case draws more power. Should I infer that you believe the9ah batteries are a far superior value after giving effect to price/cost? I concluded that before your observations but that just ices it.
Jared
Doesn’t that just side-step the question of whether any 20v tools are actually operating with sufficient current draw to have this outcome?
X Lu
Great question. Which would suggest that 20v is merely marketing hype vs 18 volt which is what I believe. All that matters is power at the tool head. Motor technology while it has its limits is really impacting the value of the voltage arms race.
MM
Everyone knows that “20V” is just an arbitrary number for marketing purposes, and that’s besides the point.
The question here seems to be how the two different cell types and wiring configurations compare to each other. The voltage is immaterial, Flexvolt batteries operating on a 20V Max tool and 20V Max batteries are both the exact same nominal voltage.
High & Mighty
I don’t think it really matters comparing technical aspects or anything that people don’t really pay much attention to such as watts or battery cell types or series & parallel wiring configurations.
The only way to get a real understanding of power & longevity capability is to put these batteries under the most demanding of tasks. And what better way to do so than ripping some nice, fresh green pressure treated lumber if you’re really interested in knowing just how much power (or a lack thereof) these batteries are actually putting out.
Might I suggest a fresh green 12′ two-by or 5/4 deck board for conducting this matter of show & prove testing. If you’re really feeling brave try notching out a 6×6 for a double band & then try crosscutting it. On all four sides.
By doing this, you’ll find out very quickly just how weak cordless tool batteries & the tools themselves really are. You’ll notice almost instantaneously the lack of power needed for workhorse capability. No doubt that this ultimate test of show & prove discredits any marketing claims of more power in a cordless, brushless power tool motor.
The dead giveaway is the repetitive stopping of the motor. This is due to the lack of strength in its ability to power through the load.
There’s other methods of testing, but I find this particular one to be the most demanding for overall battery capability as well as tool capability. Especially for the brushless electronics.
Harrison
I get what you’re saying- lots of brands have been making bogus “Corded-Like Performance” claims for years.
With 18v tools, that always involved trickery like thin kerf blades, and other efficiency gains, that would allow a less-powerful tool to deliver a similar “number of cuts” or other semi-arbitrary performance metric.
Since brands have started building higher voltage batteries, things have changed.
Sticking with the brand in the article, the Dewalt Flexvolt grinder for example can put out an honest 2300w. A corded grinder of similar size and weight (at least here in North America) can only use about 1500-1800w. Throw in the brushless motor that uses the power more efficiently, and you are able to get an additional 30% more usable power out of the wattage that the Flexvolt has available.
Same with circular saws. Go watch some videos of rips with cordless 36/40/60v cordless vs traditional corded saws. The cordless saws win.
End of the day, the results and numbers don’t lie, there is a finite amount of power available through a 15a 120v outlet, and unless we overhaul our entire electrical grid, there is no way to change that. Expect battery tools to continue to outperform corded tools by increasingly large margins as the battery technology continues to improve.
MM
“Same with circular saws. Go watch some videos of rips with cordless 36/40/60v cordless vs traditional corded saws. The cordless saws win.”
Exactly. There was certainly a time, just a few years ago, when cordless tools lagged behind the power of corded. But now that threshold has been crossed. I think it was Wranglerstar that did one of the first videos doing a head-to-head comparison cutting thick hardwood with the classic workhorse, a corded worm drive Skil, vs. the Dewalt Flexvolt and the Flexvolt absolutely spanked the Skil. No contest. And it’s not just Flexvolt. Any of those higher voltage platforms, and some of the higher current 18 volt options like Milwaukee’s M18HO or Dewalt’s Power Detect is capable of outperforming corded.
And there are cases of larger battery powered tools giving gas tools a run for their money, like the MX Fuel 14″ cutoff saw.
Harrison
Yup, that video is pretty eye opening.
Only thing I would disagree with is 18V HO… While the tools do perform well, (and totally adequately by my standards), it is still very much down to ‘efficiencies’ like the aforementioned thin kerfs, and brushless motors. There is no way they are able to deliver 1800w of continuous power, as that would involve pulling 100amps through massive #3 conductors.
Some of their tools probably come close- like the 1 3/4” Fuel SDS Max- but in my experience, these tools are not able to run more than 10 minutes at full-load without the batteries going into time-out mode.
Big Richard
Sorta related, thought people might like some of this:
https://www.mynewsdesk.com/us/dewalt-usa/pressreleases/dewalt-r-introduces-several-new-outdoor-battery-powered-products-at-gie-plus-expo-demonstrating-its-continued-innovation-in-electrification-3137790
Jeremy Solsbery
Waiting to see when a 5ah compact will come out.
Ron
I’d be surprised to see anybody come out with a 5-Ah compact pack anytime soon. They’d be likely to overheat quickly during demanding tasks.