Look what I found in the recycle bin

I’ve started to get picky as well. One of those 40v ryobi is the 1300mah one. The one on the right op4026 the good ones are the 4040 like on the left. A lot of the ryobi 1.3-1.5 I’ll leave there. Or take to go dig in another bin. I usually walk up with stuff so I don’t draw much attention. The only place I can dig freely is lpwes. Since I worked there for a couple years and still know some people. Best buy only ran me off once. I prefer the 2.0+ tool packs I already have like 70 1300mah 25amp lg cells from ryobi 40volt. I don’t really have much use for such low mah cells besides vaping. And hurricane preparedness.

The battery monitoring chip in the Ryobi lithium packs (18 and 40V) will disable the Pack by opening the large FET (s) if the voltage drops below the LV threshold and not allow further discharging, but it also prevent recharging so the Pack is “bricked”.

Theoretically, if you can open the cover and manually charge up the cells directly from below the LV cutoff, it should be possible to un-brick it and use it once again in normal operation. i did this on 3 packs to test it out and they seem to be holding.

Those older packs with the 1300 mah cells may not be worth the effort since they are selling the new packs online with 2200 mah cells, 20 cells for $145 is ~$7/cell delivered to your door with brand new cells in a pack. That seems really cheap and you don’t have to worry about your garage catching on fire while you sleep because some salvaged cells went thermal. just sayin’

You are certainly right about that, I will not disagree.
In any case I still believe that it is the self discharge after a pack is fully depleted that is responsible for so many “like new” packs ending up in the bins. That 40V Ryobi seems to be disproportionately prevalent in the bins perhaps because they are used in “seasonal” yard tools. Just the kind of tool pack that will sit around for months slowly discharging itself during the off season.

I will say this, once you mentioned that bounce back effect it got me thinking back to where I compared the total discharge capacity of a cheap Carbon-Zinc AA cell versus an Alkaline.
At low current draws, 200 mA on the OPUS, the Carbon-Zinc kept bouncing back overnight and as I added each discharge session the Carbon-Zinc cell approached the total discharge capacity and probably would have exceed that of the Alkaline. The Alkaline would bounce back also, but not a much as the C-Zn
After a week of overnight rests and discharge sessions I lost interest in the experiment and didn’t continue on.
What I did learn from it though was that ordinary Carbon-Zinc cells are probably a better choice in low drain appliances such as computer mice and TV remotes.

I started the bounce back test with a drill pack, and you are right. They bounce back quite a bit overnight after the initial low cutoff at high draw. Knowing that is a relief to me as I now realize that a discharged pack is not sitting on the ragged edge of the cliff, ready to fall off.

I had been so busy, I didn’t even notice one of those 40V Ryobi’s was a 4Ah. :person_facepalming:
After all the speculation there is no mystery as to why those three packs were in the bin.
Actually 2, one of the 2.4Ah packs charged up and works perfectly and a full capacity. I have the tools and the charger :wink:
You are right, 1300mAh cells are not that useful, but functioning packs are, to me.
As for the other 2, after taking them apart I found that the 4Ah pack had all of it’s cells sitting at 3.3V

No hope to repair the BMS board, but the cells are in good shape.
The 2.4Ah pack has a similar problem. Both look as though they were standing upright and got wet. All of these cells are sitting at 2.8V Both of these 2 packs came from the same bin on the same day.

As an experiment I will clean this up and perhaps replace the FET. Even if I get it working, I will never trust it.

You are right! Even though that pic was shot in the garage those packs did not stay there. I put them back into my van which is parked away from the house. Until I get a chance to unload it they will stay there, then they will be moved into the shed.

2 years ago I performed an experiment and did just that with some drill packs. All held their voltage for 1 1/2 years even though they were out there for 2 summers and a winter. They perform surprisingly well considering.
BUT I DO NOT TRUST THEM and they stay out in the shed.

Those screws on the heatsink are all rusty and nasty, but i’ve repaired circuit boards that looked much worse. Alky-hawl and your wife’s toothbrush oughta clean er right up…

Craftsman = Ryobi

With all the packs I have pulled, I have never seen a Sears Craftsman Li-Ion pack.
Today I found one. As soon as I held it in my hand I suspected it was built at the same factory as the Ryobi.

The labels on the bottom look like they came of the same press.

Same cells, FET’s and heat sink.

Similar case and parts.

This last shot is a 100% sized picture of the BMS boards. The basic boards are identical and for the most part have the same identical componets. They differ only in some features that are specific to each brand. Pads are used on one or the other depending.

Just thought it would interesting if I displayed this.

Of the 4 ryobi packs I’ve found so far all 1.3ah cells the BMS board screws have been rusted. Looking like water damage of some sort. Testing my cells now finally getting around to tearing it down. I misplaced my t8 security bit for the bottom two screws so had to get another. Besides for high amp vaping. There not bad for testing a light you just built. They will provide low resistance and high amps for a good 5 mins. But for as edc use not gonna happen. For night lights work fine for several nights. I’m keeping them mostly for hurricane back up. I’ve given a couple away. To get people away from ultrafire batteries.

If you can use the full packs. Then the smaller mah would be useful. The one I got seemed to be working. So far all 20 cells same 3.63 volts maybe it wouldn’t charge right after water damage but 2 lights lit up on the battery charge when I pulled. I didn’t get to check today. Home depot was bogarting there bin today. Found one laptop pack at lpwes. A good one actually in frustration I damaged 5 of the 6 cells. Of course the garbage packs open right up a good one close to full mah is epoxied together.first time I’ve actually damaged the cells before besides a wrapper.

Just all the pack pulls I’ve kept over the last several months I can only imagine the 10s of millions of good cells that go to recycling yearly unclaimed. I swear I’d love to be the guy who goes and picks up all the bins in the area. After being ground zero for katrina. I’d like to be stocked up for immediate family to have a handful of lights and batteries for a couple weeks. Its usually a week or two before power comes back on. Also good to save my good cells and use these around the house.

Maybe one day I’ll find one of those 56v packs. Or some milwalkee 6.0 packs. These 1.3 ryobi 18 and 40volt are getting old. Still undecided if I’d grab one or just leave it next time. Just hate to see good cells be recycled for no reason.

Yes, that is very interesting, thanks for sharing. Would you be able to determine if the processor chip U2 has a hitachi part number underneath the white marks.

Right your are!

I grab any and all of the Ryobi 40V and packs greater than 20V. I figure it out later.
That 56V 4Ah Echo looks new and 3 of 4 status lights are lit.
The Makita 4Ah pack is absolutely unused and all cells are in like new condition. I have no way to test if either pack will charge or discharge through a tool though. All I know is that the cells are in perfect condition.

This can be dangerous because sometimes people throw CFL’s in the battery bin. At this point I can pretty much tell the brand of battery by feel, just reaching in with my hand. I don’t even need to be able to see it.
Of course physical condition requires eyes on.

Sadly I don’t find anything super awesome in any of the bins in my area so I’ve not gotten picky. I’m grabbing what Li-ion packs there are.

You can get 6 of the OP4026 1300 mAh packs “broken” for $80 shipped on ebay as well. It’s not bad at $0.67 a cell if you have a use for the 1300 mAh cells. Of course I’d prefer they were free and found in a recycle bin but that’s a good cost per cell. Since the batteries carry a 3yr warranty I wonder if it’d also be possible to get a warranty swap on them without a proof of purchase just going by the mfg date on the pack and by calling customer service.

Well I found a 3rd 40V 4Ah pack in the bin in a store in Canada. It too had been used only a few times and was tossed. When I opened it up, it also had signs of water damage?
This is 3 of 3, 4Ah packs with the same cause of failure. Could these come from the Ryobi lawn mowers and somehow get wet with use?
All cells are sitting at 3.57V, so I am hopeful that the cells are OK

It would appear the water enters via some vent holes for the FET’s

And the angle the battery sits in it’s cradle could provide an easy entry point should any moisture pool in the bottom!
Maybe a really, really dumb design.

It seems like they advertise them as being waterproof or something—i had noticed that dumb design also, and if the FETs get wet, short and fuse out, then they will open the low side of the pack and brick it—no way to charge or discharge after that. The average person has no choice but to just pitch it in the bin.

I am hoping that is all that is wrong with this pack, blown FET’s.
They are easy to replace and I have done it before. :innocent:

It looks like Ryobi realized there is a problem with moisture getting inside their 40V packs.They have come out with a newly designed pack, the “OP40261”
Here is the old number next to the new.

Here are some pics of the FET-Heatsink area. There is a more massive, material wise, heatsink and NO ventilation holes.
Perhaps because battery packs have a limited run time, a more massive sink can be used in lieu of ventilation.
Note the insulated heat shield to protect the end caps of the cells. This sink must get very hot!

This is where vent holes used to exist.

The rest of the pack has been redesigned too.

I found this particular pack fully charged, but drawing more than 10A shuts it down. The “fuel” gauge doesn’t work but it will charge back up once it is depleted. Ordinarily I would think it has 1 weak cell pair that falls below the low cutoff voltage when there is a heavy draw, but that seems not to be the case here. I’ll try a heat gun on the circuit board and see if that repairs a poor solder joint somewhere.

thanks for posting the new pack—i had noticed the part number on the new packs for sale in the store and wondered what was the difference. Wonder why they didn’t go with the 5Ahr pack with the new design?

i had nearly finished tracing the circuits of the older design, and now they go and change. Probably a good thing since so many packs were “failing” with good cells.

i doubt they left the part numbers intact on the microcontroller and cell monitoring chips—the two quad flat pack chips. i’ll try to look them up if you can get the part numbers.

and the new packs are more of a pain to disassemble since the cells are completely enclosed in the holders which snap & screw together.

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.