We recently posted about the new Dewalt FlexVolt 15Ah battery (DCB615), and then again about why guesses about why its internal Li-ion cell configuration are important.
Your comments in the discussion sections have been awesome, and I feel that we’re getting closer to the truth. We could just wait a couple of months until the new battery launches and Dewalt makes additional announcements about the types of tools they designed this new battery for, but where’s the fun in that?
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In this post, let’s examine changes to the battery’s tool connection. But first, a recap.
There are three theories as to the underlying engineering within this new Dewalt FlexVolt/20V Max battery 15Ah battery.
- 30x 18650 sized battery cells
- 15x 21700 sized battery cells with extra cooling
- 15x 21700 sized battery cells with extra protection
Compared to the next-highest capacity FlexVolt battery, this one is longer and heavier. It’s appreciably heavier, by ~1.3 lbs. And, this battery has a boxier geometry.
The size, weight, and shape of the battery can be directly related to having to fit a higher number of smaller cells than the 9Ah and 12Ah batteries. Or, if it’s engineered with 21700-sized cells, there’s something else going on, such as added cooling components.
A lot is different about this battery, and it has been interesting to think and talk about the what and why until we know for sure.
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Take another look at the new Dewalt 15Ah battery. What’s this tab jutting-out at the top? It appears to be on both sides of the battery. What are these wings (tabs?) for?
The tool connection plate is also different than for Dewalt’s other batteries.
Dewalt has come out with new DCH735 and DCH775 rotary hammers, and one of the updates compared to predecessor models is an updated battery connection designed to accommodate the DCB615 15Ah battery.
Dewalt also says:
For those that have already bought the DCH733 and DCH773, we will have a service part available in September so that users can upgrade their existing tools to accommodate the DCB615. More details to come as we get closer to the launch.
Interesting, how the older model appears to have a bolt-on interface…
Let’s talk about Milwaukee MX Fuel.
Milwaukee launched a new cordless power equipment system that is completely separate from their M18 line of cordless power tools. One of the reasons for this was so that they could design a new battery interface that can endure the mechanical demands of heavier duty tools. Their 18V-sized interface just wouldn’t work on heavier duty tools, such as a jackhammer.
So, rather than create compromises, Milwaukee designed a new battery system.
Dewalt has taken a different approach to their cordless power tool advancements. FlexVolt batteries are backwards-compatible with 20V Max. They had a separate 40V Max line of cordless outdoor power equipment, but it has since been discontinued, with the brand choosing to focus on 12V Max, 20V Max, and FlexVolt 60V/120V Max offerings.
To power a new higher-level of demanding cordless power tools and equipment, longer runtime or greater power delivery is part of the challenge, and the physical connection between battery and tool is another part.
Is that what we’re seeing here?
The 9Ah and 12Ah batteries are constructed from two half-shells fastened together. This 15Ah battery appears to have side panels, top and bottom covers, and a separate component also fastened on top, in front of the tool-interface and electrical connections.
The new Dewalt DCB615 battery is built very differently.
This is a much larger battery, and it also looks to have been significantly strengthened. There are what, 5 structural pieces screwed together?
It has become clear that battery does not simply offer a bump-up in charge capacity.
Dewalt’s outgoing rotary hammers, DCH733 and DCH773, look to have fastened-on battery cages. The new models, DCH735 and DCH775, do not.
I am guessing that this was done to strengthen the tool-battery connection.
Here is another look at the DCH773 compared to the new DCH775.
There are two options – Dewalt could have launched the two preceding rotary hammers to be have upgradeable battery interfaces, but the DCH733 and DCH773 were announced nearly 3 years ago, in July 2018. I’m leaning towards the assumption that the battery cage being an interface-strengthening and support feature.
The new rotary hammers have a more streamlined battery interface. Existing FlexVolt batteries still need support, and this looks to have been implemented in a tidier way than the seemingly bolt-on support cages.
With the rotary hammers now presumed to feature an updated and strengthened battery interface, other new tools might feature similar engineering. But, then why does the new 15Ah battery appear to have added retention or strengthening geometries?
I’m sticking to my guess, that new tools are coming. I would assume that those tools will have strong battery connections that benefit from the engineering that went into the DCH773 and DCH775 tools, and the new 15Ah battery could provide additional support on top of that.
Here is what we know so far:
1) Dewalt updated their new rotary hammers with a reinforced interface that doesn’t require the bulkier cage-like support of preceding models.
This suggests a stronger connection that can accommodate existing FlexVolt batteries.
2) Dewalt launched a new 15Ah battery that is larger and heavier compared to their next-highest capacity batteries. It is also built very differently, and the presence of additional screw-fastened housing components suggests it has a much stronger case.
This takes me back to Milwaukee Tool’s philosophy behind the MX Fuel cordless system, that tools that can deliver the next-level of power require a battery connection that’s up to the task.
3) Things are different under the surface as well. The added battery size and weight cannot solely be tied to a (potentially) stronger and more secure interface. What kinds of tools was this battery designed to be capable of powering?
I don’t know what’s coming next, but I am very excited to find out.
Thank you to everyone who chimed in with their observations, insights, and theories as to the engineering features and differences and their implications.
Jared
Which field do you think Dewalt will use this battery tech to expand-into first?
E.g. Outdoor OPE like a snowblower, rototiller, backpack blower etc…
Or maybe HD construction equipment like these Rotary hammers seem to suggest. Like maybe there will be tower lights, cutoff saws and jackhammers.
Something else?
philip s john
My guess 14 inch demo saw 2 x 60 v. Or 9 inch grinder 60v and 60v impact gun.
My cell configuration is 2 rows of 7 and the 15 in the middle. 6.8 long this would be tight. But 3.4 high is same as 10 amph battery.
philip s john
Sorry. I meant 21700 x2 rows of 7 offset sitting in the valley of each cell and then the last one added to a row… could be top or bottom and one end… not sure which end. Obviously still in a valley.
Aaron SD
I’d think anything with heavy vibration to explain a stronger interface
Jim (Philly Fixed)
The battery is an extra 1.3 lbs? Geez! People are just gonna stick with corded at some point!
philip s john
Yup. Mx went to the far off the deep end in weight and price. This 15 and large tools is still ergo friendly.
Corey Moore
I’m with you on the new tools designed around this new form factor, very curious what they have in mind. This 15ah is the first battery I honestly don’t think I will have a use for or will be seeking out any time soon. No point in the hardware adapter on my 773 for identical performance, and I don’t feel like making my DCD470 any heavier. The 12’s feel like the sweet spot for me, plenty of runtime and form factor matching the 9’s doesn’t give any drawbacks when using them on my grinder or rear handle saw. Interested as I am, I feel like there’s a decent chance they might waffle this, kind of a “half a$$ attempt at two things” possibility, if that makes sense? Mx fuel didn’t strike me as a bold move with new batteries-there’s a clear gap between what they’re doing with MX and what personal power tools are doing. It makes plenty of sense. I’d hate to see DeWalt splinter further with more random OPE or undershoot on some seriously heavy duty stuff just to try and make 60v a jack of all trades deal.
philip s john
Oh yes. I agree. This could mean a 120v snowblower at 15amp is in the works. I maybe interested in that.
Milwaukee m18HO is nut cutting it. Dewalt 6o v grinder kill mil 9 I grinder. Milwaukee HO trips out. Another line between m18 and mx on its way for sure.
I bet dewalt could do a 9 inch grinder with 15 amph for cheap. And it would work the best. My only hope is the dont make it to long. I think there is room to have battery under the handle. May look weird though.
MicahMc
I would LOVE to have a DeWALT snowblower! I would be totally Dewalt/electric for all of my outdoors needs!
philip s john
Wings have to be the release mechanism.
JoeM
I’m thinking something similar… Kinda…
I think those are quick-release tabs… they’re going to be capable of “Grabbing” the tools they’re used on, much like a belt or pocket clip. Ensuring the connectors are always far enough into the interface as they need to be, and that there’s little-to-no kick-back capable of dislodging the battery.
We might not be able to see how they work, without wearing out, until the battery is released… but I suspect this will have quite a lot to do with that new top plate having some motion to slide them vertically for release… They slide down (and off what they’re grappled to) when you press the battery release button?
We don’t really see much on the 775 for these tabs to grab onto… but perhaps we will on the interfaces for things like the new models of Mitre Saws, Table Saws, and larger Air Compressors? It may well be the secret to these new little “Wings” is right in front of our faces on the newer 775 Hammer drill. We don’t see the two engaged with each other yet, so we can only make as educated a guess as we can, with what we have.
philip s john
M18 ho grinding and charging is pitifully horrible. Both ho ginders and super chargers and batteries fuel gauges sometimes fail to operate properly when hot. They really screw you around with on and off and wrong charge info. And then the 18650 packs are useless. This is exactly why dewalt went to 60v brushless and biggest bat with 18650 is a 6amph flex.
philip s john
I think the cage was made redundant as fit tolerances are better between bat and tool. Another example is gen 1 60v line trimmer vs gen 2 attachment capable 60v.
Nathan
the cage also prevented the longer battery length.
note the black piece not only sticks out a bit – and is inline with the normal battery rail tab.
It also has slots in the wing – like something could slide down there and lock in. perhaps there
Only need I could have for that is OPE runtime. maybe the tablesaw if I had one – since the table saw isn’t X2 and has the ac adapter.
I could see a chainsaw that would maybe tab lock the battery – but also have a battery lock out feature. So you can’t put the battery on accidentally Odd I know
ONly 20V tool I would want to put this on is maybe a light.
philip s john
The slots must be for vibration too. A spring action. So still easy to slide In and out.
philip s john
Flex 15 is now right at the limit of stated wh of 100 x 3 on bottom of bat…along with red clip in place to bring on a plane.
EHC
Wild guess – attachment points for a fall-protection lanyard? Increased weight makes me wonder if they want to guard against battery disconnection in the event of a mechanical shock.
Plain grainy
I’ll go in a different direction. Those may not be tabs at all. After reading reviews on the Dewalt lawnmower, a common complaint was the super hot 10ah battery’s. Those tabs may be cooling passages to combat the intense heat build up.
Plain grainy
As large as these batterys are getting, they might be going to an internal fan. One (tab) passage is for a filtered intake, the other side passage may be the fan discharge. Looks like a easy 4 screw fan replacement if it fails. Just my far out guesses.
JoeM
Yeah, I tried to think of that as well, but, proportionately, they don’t seem big enough for that kind of vent. I think part of the problem is we haven’t seen it front-on yet, to my knowledge.
Now, if there’s a forward-facing grill of some sort for air intake, or a fan system, then those two tabs make a very good exhaust route. I don’t think they’re quite big enough to be heat sinks, but exhaust holes as you suggest? If there’s a forward facing fan, I would believe that wholeheartedly. Only problem is, that would absolutely rule out this battery being one of the “Oil Sealed/Oil Resistant” FlexVOLT batteries that were made for the OPE line a while back. When there’s that much sealant, and lack of air flow, I would imagine they would heat up quite a bit faster than any standard equivalent size. It may well be true of this 15Ah model as well. Solution for the air, but certainly not good for, say, the Chainsaw or Lawn Mower, where there’s a little bit of oil circulating through the system to keep it rotating.
I like your thinking though, Grainy.
philip s john
I have owned both lawn mowers. The first gen with the 5 amp batteries at 2x 20 for 40 volt did not melt. Lol
So 10amp with 20700 cell is not a issue. Improved motor. 1 inch more on blade.
What can happen is 2 different bats and only 1 will take all the heat always the smaller one. Always best to start with same amph and fully topped up. This is exactly why dewalt is leading with the flex one bat on hand tools that makes sense and only 2x configuration on equipment. Only Milwaukee HO tools and batteries are tripping out due to heat. Remember how much hype they spewed on cool bat tech and all at 18v. Worlds first. Zero degree. All hog wash when used constantly. Not bad tools if you can spread the use out. But my dewalt flex tools never let me down. Never trip out . Rare to cool pack for charger. And 20 40 60 and 120v for real better than corded power and convenience.
Plain grainy
I didn’t realize until I reread Stuart’s article. He mentioned a cooling component could be involved. From the lawnmower reviews it was clear there is a heat problem. The question is will Dewalt address that problem with this product? Or somewhere down the line on future products.
philip s john
I could see gen 1 getting really hot for deep grass at 1/4 acre… but I knew I could use 2 flex 9 amph. I am sure lots of small lot houses just love its performance right out of the box.
Plain grainy
Good point! If a person had a number of 6ah Flexvolt batteries, could you just switch more often?
philip s john
More cells aways good for heat. The 21700 at 40v on mower is a huge difference for gen 2.
The trick for gen 1 mower for me was too cut with blade all the way up and never let grass grow too long. This is ideal for health grass In hot summer anyway.
Not sure why people think heat is an issue with 15 amph bat. The 9 can take a beating so more cells In a 15 can take even more… i dont see dewalt going outside of its capabilities… if so. That’s when they would go with 2 x 20 or 2 x60.
The mower can be a special case for heat. What can happen is grass jam up… mulch or bag.
Chris G
A couple of observations. Looking at the picture for the 775 it is clear the base/battery slot of the tool is not only longer but also wider and deeper. It completely swallows the 12ah, including the release button/latch
This means to things the tool will absolutely engage the new tabs with the extra width and depth.
It also means that if this is battery cooling the fan may be in the tool! It may not have to be in the battery. This would allow it to be sealed while in use.
Also we have seen the opposite end of the battery I believe. It has the power LED arranged vertically.
Tim
Precursor to 60/120v switcheable batteries.
Kirk
Dewalt has 10ah batteries for the self propelled 20v mower, Maybe they’re releasing the zero turn ride on mowers like ryobis 40v “electric” mowers. I did see patent for dewalt portable power supply ride on quad and Segway. Makita just released a cordless 13″ thickness planer so maybe. 10 inch table saw, single battery 7 /10 inch dub bevel miter, 14/16 cutoff saws, maybe stationary shop tools(sanders, table planers, grinder, lathe 🙂 Think it’ll charge in the toughsystem 2.0 or box radio? I have the loud 12 amp fan cooled fast charger cost a measly $106, are they going to make a 15 amp rapid charger for what $120? Why haven’t any tool companies utilized the air that passes through tool motors so it blows down into/ onto the battery cooling it, instead of blowing all the floating sawdust in the users face??? Noticed mostly with recip saws i will block the air with one hand also ,grinders, drilling in sand. I agree with the tabs being tool grasping clips to help with the vibration, heat and weight weakening battery grooves over time with jackhammers, cutoff saws, the new rotary hammers, backpack and snowblower. My gen 1 20v oscillator grooves are loose from extreme use/ heat. Dear Dewalt, make a corded 120v hybrid adapter for all new tools please. But going back and similar to what Chris G just said, maybe the new tools will thru cool the batteries themselves. The 12v 5ah battery is their first 6 cell 21700 battery , all others previous are 3, even the 9 and 12ah, so this new 15ah most likely is 6 cell 21700.
Big Richard
The 12v 5Ah does not use 21700 cells. It is a 6 cell 18650 in a 2p3s configuration, using 2500mAh cells. And the new 15Ah battery will have a minimum of 15 cells, that is the only way to get 60v max with 4v max cells (15 cells x 4v max = 60v max)
audiovideofreak
That $349 price tag is CRAZY! Especially when you can get a 12ah for $249.
philip s john
Milwaukee could build new 40v tool line and mutivolt battery. This could be used as 2×40 on mx tools for the 80v … the new 40v could split internally like multi volt. So when split equally and the it fits m18 tools . The splitting maybe patents infringement… but would be killer.
NZTom
I’ve experienced some Flexvolt batteries (& battery mounts) failing in tools with wicked vibration: the tool battery mounts wear badly where the tool pushes onto the Flexvolt actuators in the battery, and the battery slide rails wear out on the underside. Recent battery iterations have a metal insert to combat the second issue.
The Flexvolt grinders and recip saws are the main culprits, occasionally I’ve seen it on rotary hammers as well. Dewalt are obviously well aware of the issue.
I’m certain that this will be the purpose of the “wings”, the wings may be a tough rubber composition. It will be interesting to see if the actuating tabs in the battery mounts are also toughened with a steel insert.
NB: this wear was only observed in tools that were used to an extreme amount in industrial situations: eg a set of recip saws that were used constantly 16hrs a day, 5 days a week. I think they cycled through 12 to 20 6AH batteries per day.
Anthony Sensenig
Those wing are for when you get mad at dewalt and throw the battery, it doesnt land so hard lol
AUZEUS
They might bring back the welder as well as this could be for a snowblower or possibly be the start of a lineup of DeWalt …vehicles….. I could see a couple of these running a lightweight motorcycle, scooter, or powered rolling equipment carrier. Maybe even small heavy duty power equipment such as walk behind backhoes and excavators. I used to work at an EV company and you’d be surprised at what the batteries can look like and how they can be configured.