Milwaukee 48-11-1812 M18 REDLITHIUM High Output HD12.0 Battery Pack

I came here to contact support, but reading the reviews it appears that there’s no actual support and a canned response on the website “we’re sorry that blah blah … we’d like to connect to hear more about blah blah blah, and it appears there are no real resolution.
I bought two 12.0HD batteries for my trimmer and chainsaw. 1 works ok, but not great and the other flashes red and green when put on the charger after first use/second charge. It will not take charge even after trying to push it in place with force and cleaning the contacts.
It appears that the brand is not as strong as I had the illusion it was. Poor quality, exquisite price, and poor support.
Sounds like Milwaukee is pushing the quality reputation down the drain

so after 7 12ah, 6 8ah, 4 6ah, a dozen 5ah, I finally got the 1 blinking light or 3 bars while green on charger problem. my strategy of rotating batteries to prolong life didn't really work out. after doing research, apparently..these batteries have undersized cell balancing schemes. Leading to some of the batteries in the unit to get fully charged while the rest in the unit get under charged. folks are using the b6v2 balance charger to balance the individual cell groups inside the battery. this will get you normal next ime use and charge behavior...but dont know if the out of balance condition will return quickly or take a while to manifest. some folks are soldering in a jxt-xh 5s balancing cable and using the b6v2 with the jxt-xh cable to charge and balance the batteries. expected more reliability since I had spread usage across a few dozen batteries.

GOOD POWER BUT HEAVY AFTER A YEAR SCREWS PULL OUT OF PLASTIC TO TOOL PLASE THEY SAID WAS UNDER WARRANTY BUT MILWAUKEE WOULD NOT COVE IT BECAUSE IT WAS BROKE AND THEY DONT SELL NOT HOUSINGS FOR IT

Like too many others, I have (1) 12.0 that blinks one bar for charging but I get a steady green when I put it on the charger. Tried different chargers with same result. Is there a fix for this? Of course it's out of warranty but it was only used a handful of times.

After initital charge and use battery never took a charge.

I bought the 10”sliding miter and the table saw with two new batteries so I had 3 12.0 high output batteries and 1 9.0 high output battery they all failed right when the warranty expired. The batteries are so expensive I can’t afford to keep buying them I don’t know who could. So now I have a cordless saw and table saw that I can’t even use. The saws them selves work amazing! But unfortunately what’s the point if the batteries are so expensive and are crap. I went and talked to a rep here in town today and told me I could keep them as a paper weight or they could take them and have them recycled. What the heck I am very disappointing in these batteries and the customer service I received. I have dewalt 60v batteries that are 6yrs old and are still working strong. Maybe I should just switch to dewalt cordless saws extremely disappointed.

I've owned two of the High Output HD 12.0 battery packs. Both have failed. I love Milwaukee products, but these are horrible batteries. Of course, both were just BARELY out of warranty when they failed, so what could I do. I have MANY, MANY other Milwaukee batteries in the 18V and 12V variety, and have never had any of them fail, and they've been used for almost 10 years. Since this particular battery has very obvious design problems, one would hope that a company like Milwaukee would replace it even after the warranty, even if it were with just a smaller AH 18V battery. Nut so far, no such luck. Very disappointed, considering the high cost of these batteries.

The HD12's that came with my mower are terrible. Purchased April 3, 2022. For the first several uses I could cut lawn twice without recharging. After 18 months, I can not cut lawn once on a full charge. I have had to mix and match with an XC 8.0 just to get some performance out of it. This battery should be discontinued or recalled. $250 for a subpar performance is disappointing.

I have a total of 16 HD12.0 all purchased in Ottawa within 2 or 3 weeks of each other.

All batteries tested using Rigol DL3021A set to 10A discharge current and 13v cutoff (2.6v/cell) within the same 24hr period after all had been fully charged (solid green light for >1hr).

6 of 16 are in the 11Ah range and might have hit the 12Ah mark had they been dangerously discharged to 2.2v/cell. Not sure what discharge voltage Milwaukee uses to arrive at 12Ah rating but for comparison purposes 2.6v/cell is adequate.

Interesting that the 3 worst batteries are SN 436, 439, 440. While a statistically small sample group it’s very clear that the cells used in those 3 batteries were from the same batch and indeed very very defective. I guarantee whoever owns 437 and 438 also has dead batteries. That said, given the variability of measured Ah capacity vs serial number I would argue that all batteries manufactured between 190521 and 190531 are equally defective (i.e. have at least 1 if not more lazy cells).

When I asked to file a warranty claim with Milwaukee the Ottawa Factory Service Centre promptly told me that because they were out of warranty there was nothing they were going to do. They then ended the phone call giving me no alternative other than to post my findings so that others don’t fall into the same trap as I have. Yes.. I now have $6000 worth of paperweights.

The fact that they declined to even consider testing them is a clear indication to me that they understand there is an issue with these batteries and it’s not worth their time, that this isn’t a anomaly. This is further reinforced by the overwhelmingly poor reviews they receive here and anywhere else they are sold.
Special thanks to Milwaukee for treating their customers like dirt and NOT standing behind their name.

If you want to fix this and stand behind your name Milwaukee feel free to respond to my eTicket.

SN Measured LED Status
**504 11.2Ah, 4bar,
**416 11.1Ah, 4bar,
**427 11.1Ah, 4bar,
**471 11.1Ah, 4bar,
**473 11.0Ah, 4bar,
**428 10.9Ah, 4bar,
**773 9.0Ah, 4bar,
**525 7.8Ah, 4bar,
**423 7.7Ah, 4bar,
**629 7.0Ah, 4bar,
**522 7.0Ah, 4bar,
**417 5.3Ah, 4bar,
**292 3.6Ah, 4bar,
**440 3.5Ah, 3bar,
**439 2.2Ah, 2bar,
**436 Dead, 1 flashing bar,

The two HD12's that came with my mower are terrible. Purchased June 1, 2022. For the first several uses I could cut lawn twice without recharging. After 18 months, I can not cut lawn once on a full charge. A pair of 4 year old HD6's work better. I hope this battery has been discontinued and recalled. A pair of $250 paper weights