All this from the same company that wanted to make opening the hood a dealer only activity. What a shocker!
And BMW on Daimler's heels with the patented security fasteners: https://theautowire.com/2025/12/28/bmw-patent-reveals-branded-screw/ On Wed, Nov 11, 2026 at 12:47 PM Danny Ames via EV <[email protected]> wrote: > What shitty thing to do to their customers. One failed cell locked a > Mercedes EQS battery via permanent BMS fault P1C80, requiring a $30,000 > dealer replacement. By reading slave BMS EEPROMs and mapping 108 cells, the > lockout was cleared while preserving original calibration. Dual parallel > 400V strings isolated the faulty side, enabling limited drive on the > healthy half—highlighting EV repairability’s role in sustainability. > Danny Ames > > ------------------------------------------------------------------------------------------------------------- > A locked Mercedes EQS battery won't even let you repair it. One cell dies, > the slave BMS latches the whole pack, throws P1C80 and kills the high > voltage — and here's the trap: you can't just clear it, the fault is burned > into the BMS memory and no diagnostic tool on this planet can wipe it. > Dealer answer? New battery. Thirty grand. For one dead cell. That's exactly > where we come in. We cracked it the only way that actually works — read > both slave BMS EEPROMs byte by byte, decode the stored faults, map the > internal resistance of all 108 cells, and watch the failure replay itself: > cell 12 in module I collapsing from 3.8V down to 1.5V under load while the > BMS counted down to lockout. No scanner shows you that. We pull it straight > out of the chip — and we even caught the next cells starting to go before > they strand the car again. And here's the clever bit nobody talks about — > this pack is really two batteries in one. Two 400V strings running in > parallel, each on its own BMS. When the right string went bad, the system > did exactly what it was built to do: it cut the faulty right side off from > its own control and kept the car running on the left string alone. The car > literally drove on half its battery, limping along on the healthy left side > while the dead right one sat isolated — until the left slowly drained > itself down to empty. That's redundancy doing its job, and most people > never even know it happened. And get this straight — the lockout is wiped > while EVERY byte of the original factory calibration stays untouched. No > donor BMS. No swapped-in module dragging someone else's data into your > pack. Nothing compromised. The battery keeps its own brain, its own > calibration, its own identity — just without the fault. That's the > difference between a real fix and a bodge. Full breakdown, pictures and > part numbers at the bottom of the article: EQS V297 · slave BMS M95M02 + > TC277T - Cells CATL TOP A789 900 2801 · BOTTOM A789 900 9800 Faults > cleared: P1C80 · P1540 · P0F18 · P0F64 · P0B63 · P0B64 · P0B67 · U357D > Software side is done — the lockout is beaten, calibration intact. Now we > are waiting brand new modules from Poland to install into battery and > finally run the car without any locking faults and with more range. > Sustainablity of EV in comparison with ICE is measured in repairability! > Full article: https://evclinic.eu/2026/11/10/the > -mercedes-eqs-that-locked-itself-inside-a-p1c80-battery-lockout-and-how-we-brought-it-back/ > <https://t.co/dOLFfb0jBQ> > [image: Image] > <https://x.com/evclinic/status/2120266814693274078/photo/1> > <https://x.com/evclinic/status/2120266814693274078/photo/2> > > EV Clinic (@evclinic) on X > > A locked Mercedes EQS battery won't even let you repair it. One cell dies, > the slave BMS latches the whole pack,... > <https://x.com/evclinic/status/2120266814693274078/photo/2> > > > > _______________________________________________ > Address messages to [email protected] > No other addresses in TO and CC fields > HELP: http://www.evdl.org/help/ > OT: If you use an Android device, please read https://keepandroidopen.org/ >
_______________________________________________ Address messages to [email protected] No other addresses in TO and CC fields HELP: http://www.evdl.org/help/ OT: If you use an Android device, please read https://keepandroidopen.org/
