A reader wrote in with a great question, asking why his Milwaukee M18 cordless wet/dry vacuum sounds different depending on the battery being used to power it.
Jp wrote:
Advertisement
Hello, I purchased a M18 small wet/dry shop vac (not the backpack). I noticed this weekend a higher rev sound with 12.0 batteries than with 9.0 batteries. Does this indicate that the vac is like a “Fuel” product which acts differently with high-output batteries? There is no fuel branding on the vac. Would they silently upgrade a product to “Fuel” tech without the overt branding?
I’m assuming that Jp is referring to Milwaukee’s 0880-20 vacuum, shown above, a compact M18 wet/dry vac that’s been around for a while.
This is a brushed motor vacuum, and although it has been updated over the years, but not the motor. This is still a brushed motor vacuum.
Michael Q. wrote in, back in 2017, after discovering the updated design:
Michael – I’m sorry for not being able to get back to your email in a timely manner, but you were exactly right about the major differences – the 0880 was updated with a larger battery compartment to fit newer M18 batteries, and the internal storage compartment was reworked to allow for internal hose storage. There are a couple of smaller changes as well.
Advertisement
I followed up about the 0880 well after Michael’s original email, triggered by another email or two about the changes.
| Previous 0880-20 | New 0880-20 |
| 96 dB | 92 dB |
| Compatible with NiCd and M18 | Compatible with M18 only |
| Accessory storage outside unit | Accessory storage enclosed & inside unit |
| Standard on/off switch | Waterproof on/off switch |
| Flip up handle | Integrated handle |
| Flat hose end | Angled hose end for quicker cleanup |
| Flat surface area utility nozzle | Improved & larger surface area utility nozzle |
| HEPA-H12 | HEPA-H13 |
| Washable filtration | No washable filtration |
“New” refers to changes made in October 2017, and presumably no further changes or updates have been made since then.
Okay, so what’s going on with Jp’s Milwaukee M18 cordless vacuum? Why does it have a different sound profile depending on the type of battery pack used to power it?
Usually, the noise a motor makes could indicate a difference in speed or power as it changes, with even subtle shifts being noticeable.
I reached out to Milwaukee, and this is what they said:
When brushed motor products are equipped with a higher output battery pack, it could cause a little more noise because the additional power and less impedance of the high output pack causes the motor to spin slightly faster. This is often more noticeable on products that move air, like fans. On our [brushless motor] FUEL products we are able to control the motor a bit more because of the advanced electronics.
Sounds like a reasonable explanation to me.
Thank you to Jp for a great question, and also Michael Q. for writing in about the 0880 update so long ago.
Mysteries solved!!
I have one of these cordless vacuums, purchased two holiday shopping seasons ago when I spotted a great deal, and it has held up wonderfully in the years since. I’d buy it again in a heartbeat.
chip hershberger
All tools run faster on newer battery cells.
A new 3ahr will spin a motor faster, then a 5 ahr using lower draw cells.
Big Richard
But that 5Ah has two sets of cells, reducing their individual cell draw needed in half. I.e a 21700 based 5 cell battery (like the 3.0Ah) can put out 35A, as each cell is putting out 35A. A 10 cell battery has two sets of cells, so needs each set to only output 17.5A to achieve the same total 35A output, which is obtainable with older smaller 18650 cells (admittedly maybe not the 5000mAh that make up the 5.0Ah, but most 3000mAh and 4000mAh 18650 cells can put out 20A).
Also more cells usually equals more power since they have a slightly higher voltage because there is less current draw and voltage sag.
In theory.
xrh07
nope. 3 Ah taps out faster on high draw tools like circular saws.
DoresroomToolReviews compared the 3.0 HO vs. the 5.0 XC and the 5.0 was a better performer in his circular saw test.
The 3.0 HO is a 35A/630W pack.
The 5.0 is ~40-45A/720W+ pack.
Big Richard
My point exactly. Theory and practice.
Dean B
I thought something has gotten into the motor section causing the high pitched revving, good thing I checked, sounds like it is going to blow up.
Now I now
Brian
I have both versions and my original does this with HO batteries, isn’t it obvious to everyone the HO batteries provide a tiny bump on anything because they use the newer cells. Its different than the tools that require HO batteries to get 100% performance. I just hope the HO’s don’t hurt anything in the long term as I have ditched almost all my batteries for HO ones.
Doresoom
Also of note, the M18 3-in-1 vac utilizes each type of battery a little differently. Depending on whether or not it’s an HO or HD pack and the Ah rating, the vacuum provides different suction levels. I ran a test measuring static water lift on it a while back.
Michael Quinlan
Thanks for the mention. It gave me a chuckle!
andy
Any draw on a battery lowers the open circuit voltage due to the internal resistance of the battery. The larger the battery, the less the voltage drop.
John Patel
Thanks for the post! It was very informative.
Tim E.
Does the new version of the 0880 really not have the washable filter of the original, or is that maybe a typo? Does that mean the new replacement filters they’ve been selling also aren’t washable anymore? Just sold my older version 0880 so I could get the new one solely because it can fit the 12Ah batteries, but I didn’t think the filter had changed…
Adam
The manual still describes it as washable, and gives instructions for cleaning it.
Tool Junkie
Can you use the newer one as a wet vac?
Adam
It’s still usable as a wet vac. You just need to remove the filter. The operator’s manual still describes the filter as washable, and gives instructions for doing so.
https://milwaukeetool.com/Products/Power-Tools/Vacuums-and-Fans/Wet-Dry-Vacuums/0880-20