Author: Strom Trooper

Finally, the embodiment of what we already knew was possible but were waiting for the physical manifestation of the argument: a Tesla with its original battery and 600,000 km on the clock. A complete stranger entrusted us with a Tesla from Vienna, arriving on a tow truck without any supervision, solely based on trust from Google. Although the car was still drivable, it had a limited range of 100 km. It was the first time we personally documented such an event, and you have the honor of being acquainted with it. We were able to confirm through multiple analyses and verifications, following the owner’s statement that the battery remained untouched, as we were curious about its maximum lifespan threshold.

We had an inkling that the first-generation 1.5 battery could handle around 400,000 km before requiring servicing. However, this was mostly in cases where moisture infiltration or wiring damage were expected causes of failure. But this situation goes beyond all previous scales because the battery, hermetically sealed and free from moisture infiltration for the first time, arrived with only 10 degraded cells out of a total of 7,104 cells. These cells, due to increased internal resistance, caused significant “voltage relaxation” oscillations after periods of rest, resulting in a “brick short” discharge of one group of 74p cells, triggering the BMS_u029 flag. Without completely dismantling the entire block, these 10 cells will be replaced through a special extraction process and prepared for a bench test on a Solar UPS system. The block from the previous Tesla, which passed the gladiator bench test with an approximate capacity of 200 Ah, will be inserted into this battery pack, thus closing the loop of recycling and repair.

The battery currently operates at a capacity of 67 kWh or 195 Ah CAC, which represents approximately 11% degradation or 89% state of health (SOH). Interestingly, the first motor, previously mentioned as the P-Train MECH (not RMN), was only replaced at 500,000 km due to a humming bearing, and a new RMN motor was installed under warranty. This serves as further confirmation that Tesla’s LDU is an extraterrestrial overkill, ensuring the same quality even in the RMN model (Remanufactured). Tesla truly reigns as the king of the road and the automotive revolution, disrupting the entire legacy mindset of “moderate quality” and other imposed criteria by legacy groups, where the goal is to manufacture a vehicle that lasts only until the warranty expires, forcing you to discard and purchase a new one.

Today, fossil vehicle components are manufactured and tested up to 180,000 km in simulated environments. If they surpass this threshold, the system is deemed unsuitable for commercial sales because there is “no owner on a subscription.” On the other hand, everything we have seen, analyzed, repaired, and dismantled from Tesla demonstrates an absolute open-source contrast. Here, after 9 years and 600,000 km, the battery remains usable, having amortized the entire vehicle, and there was no need to replace the entire battery pack, as the infodemic often claims. Furthermore, we considered that the vehicle’s air conditioning was malfunctioning, and the lack of adequate cooling could have caused damage to a few cells. Currently, there is no powertrain in the world that surpasses their quality standards, and for the past 10 years, they have been relentlessly advancing, innovating, and raising the bar that not even the most established manufacturers can keep up with.

For the past 10 years, we have been hearing from mainstream infodemic spreaders that batteries cannot be repaired, that they are entirely discarded, that they cost more than the vehicle (only with the Nissan Leaf), that their lifespan is only 200,000 km, that they only last a few years… However, when we transitioned from maintaining diesel junk to EVs, every day of exploration brought enlightenment. We needed tangible confirmation, and for you, who sought the herald, here it is.

HRVATSKI:

Napokon utjelovljenje onog sto smo već i znali da je moguće ali smo čekali materijalizaciju argumenta u fizičkom obliku: Tesla sa original baterijom i 600000km na satu. Stigla nam ja Tesla od potpunog neznanca u punom povjerenju sa googla bez ikakvog nadzora na šlepi iz Beča, iako je još vozila ali limitiranim dosegom od 100km. Prvi put da smo osobno dokumentirali, da vi imate čast da je upoznate i da smo to mogli višestrukom analizom i provjerom potvrditi nakon izjave vlasnika da je baterija uistina netaknuta jer nas je zanimalo koji je to maksimalni prag zivotnog vjeka. Imali smo predozbu da prva baterija v1.5 drzi oko 400000km i da ju je potrebno servisirati, ali to je bilo vecinom kad je očekivani uzrok kvara prodor vlage ili oštećenje ožičenja. Ali ovo je izvan svih dosadasnjih skala jer baterija je bez greske hermetički zatvorena i bez prodora vlage po prvi put došla sa degradiranih 10 ćelija od ukupno 7104 ćelije, koje su zbog povećanog unutarnjeg otpora izazvale jaku oscilaciju “voltage relaxation” nakon mirovanja sto je ujedno “brick short” praznjenje jedne grupe od 74p a samim time aktiviralo i flag BMS_u029. Bez razvaljivanja kompletnog bloka 10 ćelija ce se mjenjati specijalnom extrakcijom i pripremiti za bench test na Solarnom UPS sustavu, a blok iz prethodne Tesle koja je prosla gladijator benchtest pribliznim kapacitetom od 200Ah ubaciti u ovaj battery pack tako da je zatvoren krug reciklaze/reparacije. Baterija je trenutno na kapacitetu od 67kWh ili 195Ah CAC što je oko 11% degradacija ili 89% SOH. Zanimljivo je i da je prvi motor koji smo vec spomenuli ranije P-Train MECH (Nije RMN) mjenjan tek na 500000km i samo zbog zujanja jednog lezaja je stavljen novi RMN u garanciji. Ponovno potvrda da je Teslin LDU vanzemaljski overkill samo da su zadrzali istu kvalitetu i na RMN modelu (Remanufacured). Tesla je uistinu kralj asfalta i kralj automotive revolucije, ometajući kompletan legacy mindset “umjerene kvalitete” i ostalih nametnutih kriterija legacy grupcija gdje je cilj napraviti vozilo da izdrzi garanciju pa da moras baciti i kupiti novo. Danas se proizvode sve komponente fosilca i testiraju do 180000km u simuliranom okruzenjima i ako izdrzi preko toga sustav je neprkiladan za komercijalnu prodaju jer “nemas vlasnika na pretplati”, dok sve dosad sto smo iz Tesle vidjeli analizirali probali popravljali rastavljali itd pokazuje apsolutnu opensource suprotnost. Ovdje je baterija nakon 9 godina i 600000km i dalje upotrebljiva, amortizirala je cijelo vozilo, nije bilo potrebno mjenjati cijelu kako to inače infodemičari tvrde i reparacija nije naučna fantastika. Dodatno smo uzeli u obzir da je na vozilu klima neispravna i da je mogući uzrok ostecenja par celija upravo nedostatak adekvatnog hladjenja. Trenutno po svim mjerilima ne postoji kvalitetniji powertrain na svijetu od njihovog i tu se bez kompromisa asevi već 10 godina i nemoljivo idu dalje, inoviraju i dižu skalu koju ne mogu pratiti ni najetaboliraniji proizvodjači. Slušamo već 10 godina mainstream infodemicare kako se baterija ne popravlja, kakao se cijela baca, kako je cijela skuplja od vozila (samo kod nissan leaf), kako je vjek samo 200000km, kako traje samo par godina… its medjutim kad smo sa održavanja dizel škarta prešli na EV svaki dan istrazivanja je bio prosvjetljenje. Nama je trebala materijalzirana potvrda, a vama tko je tražio vjesnik.

Understanding the Risks and Importance of Resetting BMS_u029 and not repairing battery pack/blocks/cells.

The attached graphic displays four modules, two of which are from separate battery packs that came to us with a BMS_u029/Weak Short cell defect, and the other two from separate packs with a BMS_u018/Capacity Imbalance error.

These illustrations reveal something remarkable. Each red dot represents a cell that is experiencing self-discharge, occurring at a rapid rate of up to 20 mV per hour or more. When isolated from the rest of the brick, these cells discharge completely within 1 day, reaching 0 volts. (Typically, a healthy cell would discharge at a rate of <0.5 mV per day, which is a thousand times slower.)

Interestingly, the red dots are only present on the left side in the BMS_u029 column, while there are none on the right side in the BMS_u018 column. This is not a coincidence. It’s worth noting that these modules are not unique, as we have observed the exact same behavior across numerous modules.

What’s intriguing is that both the BMS_u029 and BMS_u018 modules exhibit noticeable capacity imbalances, with differences of up to 15 Ah or more in the case of the BMS_u018 modules, but it is usualy 6-10Ah. However, they manifest in two distinct failure modes.

In the case of the BMS_u018 modules, the cells themselves function fine with minimal self-discharge and can continue to operate, albeit with reduced capacity. These cells can even be repurposed or recycled for secondary use, just not in their current configuration as Model S battery modules.

On the other hand, each red dot in the BMS_u029 modules represents a potential runaway thermal event .

The top left module, apart from resembling chickenpox, is particularly alarming. Having this module in your pack would be highly undesirable, and resetting BMS errors on it is strongly not recommended if you didnt find and repair defect brick / cell.

Even the lower left module has one cell that poses a risk. If that cell shorts, it could trigger a potential runaway thermal event.

Furthermore, the BMS can identify even a single cell with the potential “weak short” and flag it as such. It latches the error to prevent inadvertent resetting or overlooking during unrelated firmware updates, system reboots, etc.

Additionally, the BMS can distinguish cells with potential weak shorts from worn and tired cells with capacity imbalances. It correctly recognizes the latter as being worn and tired, but not posing a significant threat. In fact, if the charge balance improves between cycles, the BMS will clear the BMS_u018 error and restore the battery’s normal operation, albeit at a diminished capacity.

In summary, Tesla’s BMS features are known to be exceptionally stringent when it comes to safety in battery systems. Understanding the problem referred to as “weak short” or “short to brick” took time, as it was a novel issue encountered initially by ourteam. For the BMS_u029 error, the rule is activated only when the battery remains idle for an extended period (approximately 8 hours or more) and exhibits a linear voltage drop in any of the 96S bricks. Activation triggers the w117 and u029 processes. This check is performed exclusively when the vehicle is not in use, and one out of the 76x 18650 cells in parallel becomes a consumer. The resulting damage is estimated to be in the range of €2-4. Initially, it was unclear which processor and memory stored the error flag/log and where the error transmission originated from.

It is important to say after all work and research, there is no easy way to address those issues without proper training and thats why we offere it to our partners and franchises.
https://evclinic.eu/evc-knowhow-academy/tesla/hv-battery/s-x-battery-master-training-operation-manual-2023612001/

Tesla Model S X Battery Master training

Therefore, a couple of key takeaways emerge:

1. Tesla is not bricking these packs inoperable with OTA software updates(it is not programmed defect like found in Mercedes vehicles) or by surreptitiously modifying thresholds during MCU upgrades. The BMS_u029 weak short conditions in the latest BMS firmware are genuine and implemented for your safety. We have observed this behavior in all the BMS_u029 packs we have received. We have numerous decommissioned modules with identical results. The BMS_u029 modules have cells experiencing self-discharge, while the BMS_u018 cells are worn and tired.

During the decommissioning process, we remove the collector plates, as shown in the attached photos, to isolate each cell. We then dismantle the module as necessary to repurpose any good cells for secondary use.

2. It is extremely important not to reset these BMS_u029 errors without addressing the underlying issues with cells.