devRant - A fun community for developers to connect over code, tech & life as a programmer

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.