Look what I found in the recycle bin

Different layout and orientation of the cells.

There appears to be 2 current sense locations: the central trace with the necked down section looks like a custom current sense resistor on the high side of the pack, and the fat trace at the bottom left is the current sense for the FETs at the low side.

You could try soldering some wire across the necked-down section to lower the resistance and see if the “10 amp” current limit changes.

Aaron, if you have one dismantled can you post a photo of the bottom of the board?

I believe that top section you made note of is a fuse.

The fact that the fuel gauge doesn’t work to me means that it is not as simple as a poor solder joint in the high current path. I will fully discharge this pack, determine it’s capacity and then recharge it to see if anything is “reset”

Here are the numbers after cleaning the gunk off the 2 microcontrollers.

My finds from 4 bins this weekend.
2 x 2.0A Kobalt 40V, 1x 2.5A Kobalt 40V, 1x 2.0A 24V Kobalt, 4.0A Rigid pack (Samsung 20R cells)
Few assorted laptop batteries

Thanks for the excellent photos. Unfortunately these tool packs are kept under wraps.

The O2 Micro, ic U3, is the BMU chip to monitor the cells. i haven’t been able to get any information or datasheets on their devices, even with an email request. There is no info on the www, they are a secretive company with HQ in the Cayman Islands—great place for a semiconductor company…

The other device, ic U1, will be the microcontroller with firmware to run the board. The chip id has been hidden behind proprietary numbers. If we ever get the devices identified and pull the firmware then we will see the stupidity that they are forcing on us and bricking packs with good cells.

Check the condition of the electrolytic caps C1 and C6, that would be my first guess of leaky caps causing it to not work. i see a solder joint labelled “power”—it might be that you could remove that big glob of solder to take power off the controller, then solder it back to turn it on. Don’t know why they put so much solder on the cell voltage monitoring points—there is no significant current in those circuits.

i thought about the necked-down section being a fuse, but only if there is a mechanism to blow the fuse if the controller commands it to disable the pack. Otherwise i’m guessing it is a new current sense that is disabling your pack and the fuel gauge.

Those 40V Kobalt packs look very similar to the Ryobis—has anyone taken photos of the insides? i’m sure they will have the same patent number.

Here’s the internals of the KB 245-06

It’s unlike any other pack Ive taken apart or the Ryobi 40V packs. It appears the board is split into two and the front board with the battery gauge also has the main BMS stuff but it’s covered under a ton of goop.

The pack has space for 20 cells but only 10 are populated. It’d be trivial from the looks of it to double the pack capacity.

I posted your pics for you.
Is that a 2.0Ah pack or the 2.5? Maybe the 2.5Ah pack has 25R’s in it.


thats the 2.5A pack. its UR18650NSX

Small potatoes compared to what I am seeing above, but today I pulled 12 AAA eneloop cells from the bin at work. They all light my Maratac copper AAA on high, so it seems like a good start. Not sure what to do with 12 more backup batteries yet . . .

and now I see why they were in the recycle bin. Not charging immediately with my BQ-cc17, but hoping with my RC battery charger and some power cycles I may nurse them back to some health. All I have all my AAA lights full of these batteries and they have been running for 2 hours now. Should get 4-10 hours with fresh eneloops, depending on the light. Still seeming promising. These are 2nd gen eneloops, so they could be 8 or so years old. Looked like new from the outside, no obvious wear or damage. They are marked made in Japan, and PN HR4UTGA

Not small potatos, I found some less desirable Duracells in post 173
I had fun bringing back 4 of the 8 “exercising” the cells just as you plan on doing. I didn’t need them, but I still had fun doing it.
And it’s a learning experience.

That was fun to read about, thanks for sharing.

I tried to charge all 12 cells in my BQ CC17, and most just gave the blinking light, the others charged for 30 minutes or less. The blinkers I put a constant 0.1A for 15-30 minutes. Now I am running them. First set of 4 ran for 2:55 in lights that would discharge them in 4-10 hours. Not bad. I charged those 4 up overnight and am running them again for 3 hours. I don’t have a nice charger like you, but so this will take a bit more time . . . but interesting for me :slight_smile:

Today I found one of those Kobalt 40V packs in the bin. How did you get yours open. I find 4 screws on the corners. Are there others hidden under the labels?

There’s just the 4 screws and then pressure clips along the sides. I wedged a small flat blade in the top/bottom seam along the front panel (with the battery indicator). Then while putting some pressure to open the seam I ran another small screw driver along the seam until the clips popped on one side. Then just pull it the rest of the way open.

Thanks, that’s just what I needed to know. It is always embarrassing to find after hacking something up that there was one more screw :person_facepalming:
This pack was brand new but as it turned out all cells were sitting at exactly 0.0V.

That’s a 40A fuse on the right side of this board.

What I did get out of this find is a project case of excellent quality, and it is vented.


Also, I can use these “4 - 10 cell holders”

I found another drill pack in the recycle bin. It appears to be brand new!
But what brand is it



Oh, it’s one of those “No Good” brand packs :laughing:
Actually it is a clone of a Makita drill pack, the first one I have seen.
This will be very interesting to me, to see how they are made. Here are 2 real Makita packs with the clone in the center.


The one on the left is a brand new 4.0Ah Makita, clone in the center and an old spent Makita 3.0Ah pack on the right.
Looking at the 3 packs from the bottom reveals the brand of the clone.

The clone is an “AKPOWER”. I looked that brand up on the internet and there are many sellers selling them.
I opened the 3 packs to compare and find out why the clone pack was thrown away.


The first thing that I noticed is that there are NO balancing leads to the cells. Actually I have noticed that in earlier versions of the Makitas and reported that in this thread earlier on. With photobucket not linking those photos they are not now available.
It also looks like the BMS board is bare, devoid of any parts whatsoever.
However that is not the case, they are on the bottom.

I checked the voltage of each cell pair, there are 5, and found that one pair was sitting at 0.0V.
The reason this pack was tossed. It’s no good.
Already it is very evident that this pack is not constructed as well as an authentic Makita. But what I didn’t expect was that this 3.0Ah rated pack would actually have Samsung 15M’s in it! I was shocked!

Here are other pictures showing poor and very poor manufacturing techiniques.
As I mentioned there are no wires leading to each cell to sense their individual state of charge or discharge.
Also note the wimpy connecting tabs and spot welds. They are not up to the usual standards of authentic packs.


An authentic Makita pack on the left has a direct soldered connection to the terminal and is fused. Those are 2 - 50A fuses in parallel. This pack is capable of putting out close, but not more than 100A.
The clone on the right uses a wire that is spot welded, VERY poorly to the tab. And no fuse.


My take on this is that yes, this clone pack would work, and with authentic Samsung cells probably work quite well.
But it would not be as safe to use as an authentic Makita pack and I presume it would tend to fail at an earlier date.

Whats the best way to remove the spot welded strips from batteries…?

I’ve tried a few different methods but all seem to dent the battery base out, sometimes no dent, sometimes just a very little, sometimes much more. Seems to depend on how good the spot weld took… Don’t like the dent in the bottom of battery case, not sure how much it matters or not…? But would think its a bad thing for a li ion case to not keep its perfect integrity…?

You’re right, it’s easy to dent the cells and that would not be good. The welded tabs on laptop batteries are much easier to separate, the spot welds are not as robust as the drill packs.
I use a narrow wood chisel to get under the tab and press the sharp edge against the weld joint. Then I gently wiggle it to cause a slight flex at the weld joint. After awhile the weld joint fatigues and breaks off. I am most gentle on the negative end of the cell, the positive end is easier to deal with.
I have tried drilling part way through the weld, but that is not a good way as it is VERY easy to drill too far.
DON’T do that.

i usually try to wrap the tabs around needlenose plier jaws and twist them off, then use a grinding wheel or file on whatever is left.

wle

Thanks for the strip down and report on the battery packs dchomak. Nice work. :+1:

Yup, I’ve used all the methods mentioned, not real happy with any of them. You can see my dremel grinder work(lol) on the below battery top removing the remnants of the spot welds.

Anyone know what battery this is, I’ve harvested them from a tool pack or laptop, don’t remember what pack it came from.

No markings on its wrapper, but under the wrapper it says, PHK 1SA3, 084761, or maybe PHK 15A3, 084761

They pull over 20 amps in my D4, consistently pulls more amps then many of my higher rated Samsung/LG batteries ?… lii-500 says they hold 2300-2400mAh

^

Sanyo tends to use a very faint water mark looking label that imprinted on the red wrapper. Look closely and at different angles. Sometimes, they don't have a label though. I've seen these Sanyo cells in power packs, but hey are only about 2Ah capacity:

UR18650RX (link is external)