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RageBone
6y

Friend of mine killed his MacBook with some Softdrink.

Just poured it all over his poor a1502.

He let it dry for a few days, it starts to work again.
Except the battery.

Goes on Amazon and buys a new battery.

New battery doesn't work either and so he tells me about it and I as stupid as I am couldn't resist the temptation to finally work on a MacBook like my "hero" Lois Rossmann does.

So turns out the board is good.
Cleaned it up and basically nothing happened to it.

So what's the deal with "los batlerias"?

The first got hit by liquid, the second had a broken connection to a cell.
That could have happened through my friend, installing it without testing it first, or at the seller, so it being a DOA battery.

Now away from the stupidity of my friend and the situation to the actual source for this rant.

Once something happens to a modern Managed battery, the Battery Management System (BMS) disconnects the voltage from the system and goes into an error state, staying there and not powering anything ever again.
For noobs, it's dead. Buy a new one.

But It can be reset, depending you know how to, and which passwords were set at the factory.
Yes, the common Texas instruments BQ20Zxx chips have default passwords, and apple seems to leav them at default.

The Usb to SMBus adaptors arrived a few days ago and I went to prod the BMS.

There is a very nice available for Windows called BE2works, that I used the demo of to go in and figure out stuff. The full version supports password cracking, the demo not.

After some time figuring out how Smart Battery Systems (SBS) "API" works, I got to actually enter the passwords into the battery to try get into manufacturer and full access mode.

Just to realise, they don't unlock the BMS.

So, to conclude, my friend bought a "new" battery that was most likely cut out of a used / dead macbook, which reports 3000mah as fully charged instead of the 6xxx mah that it should have, with 0 cycles and 0hours used.
And non default access.

This screams after those motherfuckers scaming the shit out of people on Amazon, with refurb, reset, and locked fucken batteries.

I could kill those people right now.

Last but not least,
My friend theoretically can't send it back because I opened the battery to fix the broken connection.
Though maybe, it'll get send back anyway, with some suprise in the package.

rant

sbs

bms

fucking scammers

mothertruckers
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Comments
  • 8
    6y
    That really sucks. Argh, I can't stand people who sell other people crap. >:

    I suspect who ever sold the battery might have tampered with the BMS without really knowing what they were doing and/or not caring.

    (I'm a little surprised though that Apple shouldn't set their own keys on the battery.)

    Another thing though - there might be another reason why the BMS may have disabled the battery apart from the severed connection (which you probably can't read (PF Status, PF events) due to being unable to unseal the battery). Please proceed with caution, this battery might be unsafe.
  • 1
    6y
    @nin0x03 you seem to have more experience then usual with such stuff.
    How did that happen?

    And be assured, I have some experience with batteries of this type, only the one connection was broken, probably due to mishandling and that caused the battery to be a 2cell instead of 3, causing an undervoltage Error.

    Currently, there are no obvious error flags set, except maybe the one that there once was an error, and that the fets are still closed.
    Though it's a bit hard to understand things just by their flags.

    I think who ever it was, perfectly knew what he was doing.
    I mean, it was cut out of a device, resedue traces still on the battery.
    And then the 3000mah Vs 65xx, that I overlooked twice. I think macos only displays the designed capacity, otherwise we should have seen that earlier.

    To change it to looking like new, they had to have full access, and they have locked it afterwards, since it is currently locked. So they easily could have, and very likely have changed the passwords.
  • 2
    6y
    The first crap in that chain of events was of course already the Macbook itself. If a laptop in that price range isn't spill resistant, it's an overpriced piece of shit, just as the Crapple logo indicates.
  • 4
    6y
    Well, I'm coming from a background of being an electronic technician and happen to work with "smart" batteries from time to time. :)

    Alright then. I was thinking about things that happened prior to mistreating the battery - the disconnected cell is the obvious fault but maybe there was a previous condition like an internal short or a broken temperature sensor or a fuse event or something. (I just can't imagine getting the BMS to work with this discrepancy in capacity/cell configuration without immediate errors. Maybe the only thing that matters here is the full charge capacity, though.)

    To show design capacity is afaik quite common, but I'm not specifically versed in Apple SW.
  • 1
    6y
    I am legit more interested in knowing wtf "los batlerias" means
  • 2
    6y
    @nin0x03 I'm not versed with apple stuff either, so I only wonder how that hughe discrepancy unnoticed for a while.

    I had a good look at the cell terminals and the fuses, all looked good and individually fused.

    The connection was riped through very clean, no burmarks anywhere, no impacts or indents on the cells itself.

    It didn't explode jet, had it lying around for a while. 😅
  • 0
    6y
    @AleCx04 very bad Spanish for
    The battery /s.

    Don't know what got me to write that.

    Same with lois. Fffff...
  • 2
    6y
    Well, I hope it stays that way. :D (But from your description it seems safer than in my first assumption)

    You'd probably had to measure the fuse while no cell pack is connected but I think that's not worth the trouble as well as trying to brute-force the keys as the cell pack is probably crap anyway. Frustrating. :<
  • 2
    6y
    @nin0x03 indeed frustrating.
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