Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusing

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Well I have one more M18 HD12.0 battery pack that I tested and of course it was way out of balance and the amp hour between were very uneven as well discharged battery group cells to roughly 3.1something

This battery pack is taking the longest to charge as well but I have all 4 fuel gauge lights on which is good sign this battery probably not the oldest one either so at least I think so because I bought two at same time and the other one much later on

But it weird that all three of them had the same exact issue so what this tell me is that the BMS protection board is not best one in the world but it does let you know that they are unbalanced when you can not get all four fuel gauge lights to light

I have several Ryobi battery packs that are doing the same exact thing only three out of the four LEDs light up which is probably the same exact issue but I need to make a jig for doing this type of testing

What is telling me is that as these batteries age they might also become unbalanced as well but I have bought new batteries to replace them and use the old ones in another application and I will regroup them when I do this for better preforms out of them

I have to wait a month or more for the BMS protection boards the tabbing and the plastic battery cell holders to arrive so I can put them together in the original battery enclosure for Milwaukee

And use the Chinese made enclosure for the batteries that have been regrouped for better preforms hopefully this will be the case

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Well I torcher tested one of the unbalanced battery packs and it preformed very well and the running time was back almost normal and it is charging normal as well all four fuel gauge lights come on and it is charging for a long while in this state which is normal for this size battery pack

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

I ordered from this seller “Shop3686085 Store”

https://www.aliexpress.com/item/3256...xx__1662589135

The items have been shipped now wait for about a month for it to get here so we will see how this works out with these new batteries that I just bought and been testing

The new batteries that I tested so far are no more than 500 milliamperes hours different which is good however the charging time are not exactly the same this might not be a problem when you have 3 batteries in parallel but I am going to try to make the battery pack as balanced as much as possible for best results

How I know this is because I started all the batteries basically at the same time but the charging time varies at least a few minutes between battery cells as you can see in the picture of the results for this set of four batteries that have been tested so far

[stj]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

that charger looks a bit limited in the "width" department.
whats the largest batteries it can take?
your link is broken btw

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

This is one thing I do not like about AliExpress it is very difficult to reference anything from there website

The widest and longest battery you can put in there is a 21700 battery type 4 at the same exact time
The reason I bought this battery testing machine was that it could take the 21700 battery type

You can charge 4 batteries at the same exact time however if you use 26000 to 32700 you can only do two of them at the same exact time with two smaller diameter batteries according to manual

I have not tried this yet but I will become I have some 26650 batteries to test as well

Here is a picture of what is supposed to come in this repair kit

Battery Hookup now offers the 21700 battery however you have buy 100 of them at a time for $300.00
Unfortunately they did not have any when I was looking for them or would have bought them from Battery Hookup instead of where I bought them from I paid $1.35 more for each one but I did get a free gift for my first order so it not exactly $1.35 and also got battery case holder that I did not have either so buying them from where I bought them from was still worth the money

https://batteryhookup.com/products/1...j-2170-4100mah

This picture is from the AliExpress website page with the picture cropped so it only shows what is in the repair kit

[stj]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

This is one thing I do not like about AliExpress it is very difficult to reference anything from there website

no, thats just noob error.
same happens with ebay, amazon etc.
the shit in your addressbar is not just the item but also all the tracking crap.


with ali you just need to copy from the "https" to the end of the "html" after the item number.
like this:
https://www.aliexpress.com/item/1005003614837992.html

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Try this

https://www.aliexpress.com/item/3256804189572441.html

[stj]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

perfect link.

why does the board have a copper heatsink?

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

When I get the new ones I will carefully remove the heat sink and see what is under it I was wondering the same thing

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

I posted the results on the new SkyRc battery tester that I had bought

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Update on one of the Milwaukee rebuild battery packs the BMS protection board failure this time it just flashing one fuel gauge light no output voltage and the battery voltage is 20.64 so now I bought a couple of battery packs that have the issue with battery packs that only 3 fuel gauge light and will not charge correctly anymore

I was using the high torque impact gun on a project on my son semi truck when it started flashing only one fuel gauge light but no output voltage put it back on the charger and it work again for a few minutes and then the same thing happens again put it on the charger again but nothing this time around completely dead only one fuel gauge light blinking

This battery pack has been acting weird a couple of times before not like this it just would trip out easily but kept working until now

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

I bought two M18 @ 12 amp hour batteries from EBay that have the same exact issue with the three battery packs that I originally had before I put new batteries in them for The cost of the two battery packs from EBay was $170.00 includes shipping and taxes

Between the the two battery packs I should have enough battery cells to make a good battery pack and one not so good battery pack or just use those battery cells in something else

The two that I bought from EBay the battery voltage was anywhere from 3.4 to 4.0 volts the battery has plenty of power to run the impact gun with a load on it so this is good sign that unless it has issues that I do not know about they should be alright

Yes the description that the EBay seller had on these battery packs was as follows
Only three out of the four fuel gauge LEDs light up and the tool works you just can not fully charge the battery packs

On one battery pack I have discharge all the battery cells to 3 volts and put it on the Milwaukee battery charger and the other battery pack I am in the process of discharging all of the battery cells to 3 volts and see if the BMS board has any issues that I should know about

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Update

on these battery pack cells I have put new battery cells in three different battery packs and they all work like they did new I have one more battery pack that I have new cells for that I have left at 3.something after being load tested

Update

on the two battery packs that I bought from EBay I put new battery cells in both of them after leaving the new battery cells fully charged for at least two months or more and still have full charge voltage and four fuel gauge lights

Another battery pack that I still have to put new battery cells in this one has one battery cell bank is at 3.1 and the rest of them are 4.07

So I will have 4 reconditioned battery packs and one new one that 12 amp hour pack each

I am looking for a couple more battery packs that are having unbalanced battery cells in the pack because I have a lot of barley used 21700 batteries that I want to try them in and see how well they preform

There is an update on the taking used unbalanced battery cells 21700 power tool the amp hours are all over the place even if are they not showing signs of self discharging so you really have to test them several times when they have sat for a month or two and retest them again for the best results

I am going have to use the battery testing machine that has the best graphics that shows the results over time where you can move the results line and see the exact roll of voltage of each battery cell use the best ones for the best results out of the battery pack

I have not decided on what to do with the battery cells that have a higher self discharging issue meaning that the battery voltage goes down close to 3.0 volts or a little bit lower than that

I will have to see what kind of amp hours they have after sitting for a couple of months and see if it is worth the time and effort doing this type of project if they are half decent I might build a solar powered LED light fixture that uses these battery cells

[stj]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

dont put lithiums outdoors,
if you charge them while they are cold they can go boom,
if they get too hot they lose charge/capacity.

i just bin cells that self discharge.
i mostly use lithiums for lights so self discharge is not tollerable in emergency gear.

[CapLeaker]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Sam: for how long do you charge these M18 12AH batteries for? Just like to see how they did get so unbalanced?

Here we go: I’ve got new 18V Bosch tools with a fancy charger that accepts a Bluetooth module and pairs with the phone. It’s got fancy features that include charge batteries to only 80% or 50% storage mode etc.
So I put the charger on 80% long battery lifespan mode and used one of my older 4Ah batteries. It took about 2 weeks of everyday use for the cells to become so unbalanced, that charging would be completed within 7 minutes, and I couldn’t make the day through without recharging in between.. This battery was dead way faster than the others. So I put the charger back to normal mode and charged that unbalanced battery overnight. Works perfectly again like all the others. My fancy Bosch charger did balance the battery pack. I am wondering if you are giving the charger enough time to balance the battery pack or maybe are Milwaukee chargers straight up garbage? Don’t know. Meanwhile I did also purchase 8Ah and 12 Ah Bosch batteries. As I am starting projects I may take a specific battery pack / charger again to do some testing.

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Sam: for how long do you charge these M18 12AH batteries for? Just like to see how they did get so unbalanced?

Here we go: I’ve got new 18V Bosch tools with a fancy charger that accepts a Bluetooth module and pairs with the phone. It’s got fancy features that include charge batteries to only 80% or 50% storage mode etc.
So I put the charger on 80% long battery lifespan mode and used one of my older 4Ah batteries. It took about 2 weeks of everyday use for the cells to become so unbalanced, that charging would be completed within 7 minutes, and I couldn’t make the day through without recharging in between.. This battery was dead way faster than the others. So I put the charger back to normal mode and charged that unbalanced battery overnight. Works perfectly again like all the others. My fancy Bosch charger did balance the battery pack. I am wondering if you are giving the charger enough time to balance the battery pack or maybe are Milwaukee chargers straight up garbage? Don’t know. Meanwhile I did also purchase 8Ah and 12 Ah Bosch batteries. As I am starting projects I may take a specific battery pack / charger again to do some testing.

The Milwaukee battery chargers do not have this feature but that is not the only issue with the battery cells the one that are unbalanced are also self discharging even with out the BMS protection board hooked up to the battery cells

Yea you can try to rebalance the battery cells with a battery testing machine but it the battery cells get unbalanced again because of the self discharging battery cells there is no hope for them in the configuration that they are in the original battery pack also even the ones that do not discharge severely by themselves the amp hour results are as follows the new battery cells are 4.5 amp hours the battery cells that are in a self discharging cell pack are like 3.something but each battery cell the battery amp hours are all over the place and to make matters worse voltage curves are sometimes do not look good either

I have been testing some battery cells that were in the unbalanced battery packs and the results are not very promising yet I do not even think I have enough good battery cells to make a good used battery cells

When you have a battery pack that the battery cells are unbalanced rebalanced them and then let them sit for a month or two and do not use them and see if they are still fully charged or not if they are not fully charged anymore the battery pack cells have become unreliable and you have drastically reduced amp hour capacity

I hope this helps you with your questions

One note the battery packs that I originally bought new I have used them very hard in the power tool and more often than not I do not put them back on the battery charger until I have either no more power or one maybe two LED lights on the fuel gauge of course this is not the way to get the most lifespan for a battery pack

When you have a 12 amp hour battery pack that the fuel gauge is blinking one LED light this means that the battery cells are severely discharged it might take 4 hours or more with a 4 amp hour battery charger

But even the RYOBI battery packs have the same exact issue with the battery pack cells becoming unbalanced and I have had to fix a couple of them already I four more of the 1.5 amp hour ones with the fuel gauge on them are the only ones that I fix for myself but where I work at now they have some 1.5 amp hour battery packs that have become very unbalanced or the battery cells are completely dead and are bad that I have fixed with new 1.5 amp hour battery cells

One note about the battery packs that are 1.5 to 3 amp hour do not be tempted to use higher amp hour battery cells in them because the heat sink is not big enough to remove the heat that is generated by using the power tools on them

One note the Milwaukee and Ryobi battery BMS boards do not have balancing feature I wish they did for how much the battery packs are you would hope that they did have this feature

What is the cost of the new 18V Bosch tools with the new features that you were talking about

[CapLeaker]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Can you identify if the bad "unbalanced" batteries are repeatedly in certain spots within their battery stack? I wonder if the problem is the actual cell or if it has something to do with the battery balancing circuit putting on a constant draw on selected battery group. On the older packs it is not that each single battery is getting balanced, rather the group is split in 2. A 4Ah battery would have 1 group with 2 balancing circuits. An 8 Ah pack would have 2 groups, 4 balancing circuits and so forth. It seems that these single batteries are getting unbalanced where the load resistor for balancing is connected, because the resistor is putting on a constant drain.

My old battery packs only have 3 LED's and the Hitachi has no battery display as charge status indicator. I only charge them when they are dead (tool shuts off) or displaying one bar. The new battery packs have like 6 LED's. I've got Hitachi, Bosch, Dewalt and Milwaukee tools. But only got the big batteries for the Bosch.

The big batteries 8Ah and 12Ah and the charger are Bosch Profactor. I have some Profactor tools too. Only thing is that the 12AH battery pack needs a small mod to fit in the other regular Bosch tools (cut of a piece of plastic on the battery). Prices are sometimes real good on Amazon and for me the cheapest place to get. I watch until something goes on sale and buy it. For the last 6 months I've been collecting new tools and buy a new tool to replace an old one or something I never had before every month because I am doing repairs / re purposing rooms (built me a shop (mancave) in the basement and a reno at home. Can't afford to hire a contractor. Of course it will be slow, but I am o.k. with that and at the end I've got new tools that I own for other projects down the road and saved me tons of money doing so.

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

Can you identify if the bad "unbalanced" batteries are repeatedly in certain spots within their battery stack? I wonder if the problem is the actual cell or if it has something to do with the battery balancing circuit putting on a constant draw on selected battery group. On the older packs it is not that each single battery is getting balanced, rather the group is split in 2. A 4Ah battery would have 1 group with 2 balancing circuits. An 8 Ah pack would have 2 groups, 4 balancing circuits and so forth. It seems that these single batteries are getting unbalanced where the load resistor for balancing is connected, because the resistor is putting on a constant drain.

There is no certain place in the battery pack it varies but generally it is in middle of the battery pack not normally on the end battery cells on the outside cell but I seen them also have issues but mostly the inner battery cells are the most common issue ( or a quality issue when they are being manufactured ) or keeping them in the car or truck probably dose not help anything either

My old battery packs only have 3 LED's and the Hitachi has no battery display as charge status indicator. I only charge them when they are dead (tool shuts off) or displaying one bar. The new battery packs have like 6 LED's. I've got Hitachi, Bosch, Dewalt and Milwaukee tools. But only got the big batteries for the Bosch.

I have a feeling that when you let a this type of battery get really low and you do not charge it right away and you leave it in discharge state over a period of years it does something to the battery I am not sure exactly what it does but this is what I have noticed with the battery packs that I have

The big batteries 8Ah and 12Ah and the charger are Bosch Profactor. I have some Profactor tools too. Only thing is that the 12AH battery pack needs a small mod to fit in the other regular Bosch tools (cut of a piece of plastic on the battery). Prices are sometimes real good on Amazon and for me the cheapest place to get. I watch until something goes on sale and buy it. For the last 6 months I've been collecting new tools and buy a new tool to replace an old one or something I never had before every month because I am doing repairs / re purposing rooms (built me a shop (mancave) in the basement and a reno at home. Can't afford to hire a contractor. Of course it will be slow, but I am o.k. with that and at the end I've got new tools that I own for other projects down the road and saved me tons of money doing so.

Good luck with your project that you are doing

[CapLeaker]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

One thing is correct in you assumption… Do not leave empty batteries uncharged or attempting to charge a hot battery pack. I charge mine right away. As soon as I notice battery degradation, I charge them over night. At the moment think that you’re not giving enough time leaving the battery on the charger for the battery to finish balancing. Balancing takes hours and is not completed when the charger is done it’s charging cycle. Anyway… so far this works for me and never had any problems on any of my 15 LI-Ion battery packs for tools, various brands. I am new to Milwaukee and only got one tool with a 2Ah battery for that. Mostly I’ve got Bosch followed by Dewalt. Heck, my 15 year old batteries for the Hitachi are still working fine. They don’t have the capacity they had, but still they work fine.

[sam_sam_sam]

Re: Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusi

I have left the battery on the battery charger for days and this does not make a difference as far as the battery cells being unbalanced remember that I have had them for over three or four years by now and I use them very hard ( meaning that the battery packs is very warm to the touch) when I use them most of the time do not very often charge them when I have finished using them if they have more than 2 LED lights that are on the fuel gauge also it does not help that I keep some of them in my car at least most of times covered with a sweater so they do not get direct sunlight

I know I not very kind to my battery operated tools and I am very surprised that they last as long as they do