Best Product – The New Dewalt 15Ah Battery has… Wings?

Dewalt DCB615 Cordless Power Tool Battery

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.

Dewalt FlexVolt 12Ah Battery Pack
Dewalt FlexVolt 12Ah Battery Pack
Dewalt FlexVolt DCB615 15Ah Battery Side View
Dewalt FlexVolt DCB615 15Ah Battery

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.

Dewalt DCB615 Cordless Power Tool Battery Top Clip Highlight

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 SDS Max Rotary Hammer Differences DCH775 vs DCH773
Dewalt SDS Max Rotary Hammer Differences: DCH773 (top) vs DCH775 (bottom)

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…

Milwaukee MX Fuel Cordless Light Equipment Tools 2020

Let’s talk about Milwaukee MX Fuel.

Milwaukee MX Fuel CP and XC Batteries
Milwaukee MX Fuel CP and XC Batteries

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.

Dewalt DCB615 Cordless Power Tool Battery Top Clip Highlight

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 DCH733B Rotary Hammer
Dewalt DCH733B Rotary Hammer

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.

Dewalt SDS Max Rotary Hammer Differences DCH775 vs DCH773

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.