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It’s time for an honest review: With Stellantis OBC we have observed frequent technical issues with several EV models, which raises questions about their long-term reliability. The level of questionable engineering in their designs borders on the absurd, and it’s time to highlight the issues where owners ultimately pay the price. We’re all aware of the shortcomings in their diesel, gasoline, and hybrid vehicles, but what’s happening with their EVs is truly unacceptable. These problems could discourage buyers from EVs and lead them back to diesel – an unfortunate outcome that benefits no one
Our experience has exposed a range of problems, from restricting “right to repair” access for independent workshops (blocking schematics, software, updates, parts) to the absence of essential tools and documentation. Their support practices appear to violate the spirit of EU Regulation 2018/858, Article 61, by limiting independent repair access. Warranty conditions are extremely strict – for instance, skipping a minor service (like a wiper change) can void the battery warranty – which customers find unreasonable.
The situation is even worse for official service centers, whose technicians receive inadequate training, lack reliable hotline support, and often resort to blindly swapping parts at the owner’s expense. And even when they can identify the problem, replacement parts are frequently unavailable, leading to delays of 2-6 months, which is especially damaging for businesses left without a replacement vehicle under warranty. Worst of all are the warranty terms—these conditions border on extortion. They tie the vehicle’s overall warranty to specific components; for example, skipping a windshield wiper change could void the battery warranty, even during critical recalls where they refuse to replace faulty parts.
We’ve documented three cases of catastrophically flawed MAHLE OBC and DCDC units integrated into a single module, with eight circuit boards that overcomplicate the system to an extreme. The final IGBT board is epoxy-bonded to the cooling plate along with the DCDC inverter, with almost every board running its own microcontroller. In two cases, damage was undetectable, but Type 2 charging simply didn’t work. In one case, an inductor wire to the IGBT output burned out. We couldn’t repair any of these units after three attempts. For the second part, we’ve been waiting six months, and despite it being a factory defect, it’s neither covered by warranty nor recognized in a recall, leaving owners no option but to switch manufacturers or face potential financial ruin. This issue affects all Peugeot, Citroën, Opel, Toyota, and DS vehicles—and it’s just the beginning.
It’s as if they’re making EVs so that you’ll hate them.
After 8 months, we have not been able to resolve the issue with the restoration of the PMSM electric motor for a BMW i3 with 183,000 km on the odometer. The motor stopped working after the outer bearing near the resolver sensor failed. The owner ignored the motor’s whining noise until the bearing completely failed, damaging the entire resolver sensor and the resolver hub on the rotor. Unfortunately, the resolver cannot be purchased separately, and the same applies to the resolver hub.
The bearings are commercially available, but the problem is further complicated by the unsustainable design of the electric motor. The resolver is unnecessarily fixed in place instead of using a keyway, as other manufacturers do, which would allow for safe disassembly and servicing of the motor. Although the motor is extremely reliable, designing systems that are not maintainable makes no sense; in short, such designs should be completely prohibited.
We even managed to adjust the clearance for the position and found another original sensor, but the vehicle still throws the error “2223E0 – Inverter, Controller voltages” precisely at 60 km/h. This adds to the confusion, suggesting that there is an additional fault in the inverter, which turned out to be an inaccurate diagnostic assessment by the system itself.
BMW has been a leader in e-mobility in Europe. By contrast, many other legacy manufacturers have struggled to produce EVs at the same reliability level. However, poor decisions in manufacturing powertrain systems that are not sustainable in the long term could permanently jeopardize the prospects of the only true EV leader in Europe.
Interestingly, this drive unit is still being produced and is found in the Dacia Spring. Besides Tesla, BMW is the only manufacturer offering realistic prices for EV parts, with this motor selling for around €4,500 including VAT (Stellantis €13,000, VAG €10,000, etc.).
In this case, the repair of the BMW failed; the owner purchased a used motor, which we installed, and everything worked immediately. If your motor is making a loud whining noise, you might consider preventive repair before the bearing and resolver are damaged. Several colleagues have reported experiencing the same problem, with repairs also being unsuccessful when resolver damage occurred. It is therefore to be expected that the lifespan of the electric motor in the BMW i3 is around 200,000 km, and repair outcomes may be uncertain. This is first electric motor nobody succeeded to repair it.
DTC Code: 2223E0 – Inverter, Controller voltages
Part number: 27217613560-06, 12377626083, 0-2177512-1, 1237762607603,
I can’t believe it, but the 100 kWh pack, which has been refined from previous generations, has failed on me (and it’s not the cells causing the issue). The problem lies in a flaw we’ve been observing in fossil-fueled vehicles for the past 20 years: aluminum wire bonding. The same problem that TEMIC has failed, either by accident or on purpose, to resolve in the automatic transmissions of VAG and MB over the last 20 years, affecting 80 million vehicles, is now appearing in the 100 kWh battery. The only manufacturer we’ve noticed who has nearly perfect ultrasonic wire bonding is BOSCH, as they adhere to some “secret” recipes for long-term reliability that we observe in the aftermarket. Meanwhile, Temic, Conti, and others continue to make the same mistakes, as does Tesla in this specific case, where they didn’t account for the thermal expansion of the battery module both in width and length, nor the potential galvanization of the “wire sense” flat cable connection. Designing a battery system without any flaws is impossible, but if you ask me, I certainly wouldn’t have failed in these connections, where the wire is too short from the terminal plate to the flat cable used to measure the voltage of one group. All 16 modules in the battery system had 5 to 7 damaged connections, and the ones that suffered the most were those parallel to the longer part of the module (red line), where the expansion was greatest, resulting in the most damaged groups. Based on previous documented cases, which we couldn’t address because they were under warranty, it seems that all 100 kWh batteries will fail between 150,000 and 250,000 km. The good news is that they will never suffer from classic moisture penetration, as they have a new generation of vapor-permeable valves, lack fuse covers on the top side, and don’t have some of the other faults of previous generations (our trade secret). Furthermore, the “batteries” will never fail, i.e., the individual cells, as we estimate that the cells themselves can last over 600,000 km. However, a repair of the entire battery due to unaccounted thermal expansion will likely be necessary, but after that, it will never have this problem again because we fix it permanently!
This 100 kWh battery system has a black metal cover, meaning it is a REMAN battery (already serviced), but the problem has been documented on non-REMAN systems as well. The side effects I’ve noticed include the range dropping overnight more than usual, but this is not a rule. The only clear indication is the drop in BMS parameters by 4 kWh, from 88 to 84 usable. As a result, the range parameter in kilometers on the dashboard decreased after two consecutive charges. A third parameter was visible through measurements with our EVC Explorer tool, where one module showed noise in the voltage measurement. The worst part is that the battery started failing on the highway, but AIDBOX saved the day, acting as life support to get us to our destination. For all other Tesla 100 kWh battery owners, most of whom are still under warranty, an essential battery system service awaits them, which we have only just discovered.
Repair is not easy and cheap, soldering is not possible because it is aluminium (thermal expansion cracks soldering attempts), 10000-15000€ equipment needed beside 40-60 labor hours to finish it. This should not be done by any DIY workshops or any other untrained personel. You risk destroying battery pack.
Error code: BMS_f107, BMS_w177
Affected cars: Model X and S from 2016 – 2021 100D P100D Longrange
If we recall how our PC world began with “Hello World!”, the next generation of EV engineers should start with “Hello Evalus!” and “Hello EVCLINIC”. EVALUS is the pioneering company in safety and consulting, offering comprehensive learning about high-voltage (HV) systems and electric vehicles. Their training blends theory with real-world experiences, developed over years by a team of experts. What we offered was EVC Academy and it is extension of specialization for each dedicated defect of the HV system, but with participants without EVAL card we encountered that training of un-skilled personel is extremely dificult and probably dangerous.
EV Clinic, previously guided informally by engineers from Rimac and Tesla, recognized the need to enhance our expertise in HV safety. We pursued Level 3 EV Access Licenses to become the first third-party workshop to offer joint trainings with expert Deniz Kartal. Together, we created a curriculum combining theory with hands-on experience and real-world repair scenarios, following HV safety protocols such as disconnecting, securing, and voltage verification. This training has set a foundation for advanced knowledge in HV systems.
Example of critical approach HV troubleshooting (DONT DO THAT):
Our step toward this partnership is simply driven by our own experience, where we have encountered that a lot of “internet” people are trying to repair EVs and mostly end up destroying the entire system. It doesn’t matter what type of system—they were guided by forums or other falsely represented members, merely copying some comments on how things should be done. What has been happening in the last 12 months is that DIYers are making a “Who Killed the Electric Car 2” scenario.
The sad reality is that DIYers are accelerating the destruction of EVs, where you now find many EVs without batteries or motors, being sold in parts. But this needs to be understood clearly to grasp why. The reason is the high price of OEM parts and the high cost of third-party repairs. Lastly, it’s driven by the “internet,” where complex problems are presented as easy, but the reality is they are extremely complex, even for us, to make them reliable and sustainable. A Model S battery defect may seem easy, but it is not—where we have only a 90% success rate and need 40-80 labor hours to complete the job. That’s why we have nearly “open-sourced” our EVC Academy, which was originally intended to train only our employees to accelerate and optimize internal operations. We see the need to offer our know-how to everyone in an effort to stop the DIY path of EV destruction.
To continue developing solutions and guidelines, we can’t offer this knowledge for free. To make our mission sustainable, we’ve opened it up for a fee to accelerate our efforts.
EVALUS is now the foundation of our mission, where every DIYer or workshop can learn the fundamentals of every HV system and EV logic. Yes, you’ll learn how every EV operates, how to trouble shoot and how to follow safety guidelines to prevent injury, damage, or secondary defects (which DIYers usually cause).
The Level 1, 2, and 3 training courses from evalus.at cover increasing levels of expertise in working with high-voltage electrical systems, particularly in the context of electric vehicles (EVs) and with EV CLINIC we evelated this with our skills and expertize based on high lvl of experience from various EV HV Systems.
Level 1 focuses on fundamental knowledge and safety awareness for working near high-voltage components.
Level 2 emphasizes performing basic tasks like disconnecting or replacing components in a de-energized state.
Level 3 equips participants with skills to perform advanced work on live high-voltage components, including diagnostic and repair activities on EV powertrains
The session of trainings we organized in the EV CLINIC lab was a pilot project with EVALUS, and we now realize that every new participant of the EVC Academy will need to first complete the mandatory LVL3 EVAL CARD training. This ensures proper introduction to HV systems and operating logic before proceeding with specialized operation manual guidance for individual, extremely complex defects in EVs. We aim to set a new benchmark and standard to help DIYers and third-party workshops survive this transition, alongside EV owners.
Next appointement training for LVL1 LVL2 and LVL3 EVAL Card expert training is booked for 2025 February – max 12 participants.
Example of wrong bolt torque on Model S battery from Germany:
We are proud to announce our cooperation with the EVALUS GmbH company in the field of high-voltage safety training for EV aftermarket workshops with #evalcard. Join us for our first HV-3 training from October 7-9 at EV Clinic and receive your personal Evalcard (EV-Access-License). This is the first mission of its kind in the aftermarket sector, where we jointly form a department for education, awareness, and protection of all future EV workshops. For more information about the TGE Evalcard, visit evalcard.com. Please send all training applications in both HR language and English directly to the email: [email protected].
Ponosno najavljujemo našu suradnju s EVALUS GmbH kompanijom u području obuka o sigurnosti visokonaponskih sustava za servise u EV aftermarketu uz #evalcard. Pridružite nam se na našem prvom HV-3 treningu od 7. do 9. listopada u EV Clinic i preuzmite svoju osobnu Evalcard (EV-Access-License). Ovo je prva takva misija na aftermarket tržištu gdje zajednički formiramo odijel za edukaciju, upoznavanje i zaštitu svih budućih EV servisa. Za više informacija o TGE evalcardu posjetite evalcard.com. Sve prijave za trening saljite na našem jeziku i na engleskom direktno na email: evalus-ev AT evclinic.eu
Unstable grid conditions are the most common cause of OBC failure, especially on the Renault ZOE with the Q drive system. A case from Serbia a few months ago remained unresolved because an explosion destroyed a significant part of the EMI filter PCB. At the time, we assumed it was an isolated incident. However, another case has recently come from Bosnia with the same problem. The OBC consists of the FS200T12A1T4 Infineon HybridPACK1 IGBT, which is no longer manufactured, and the EMI filter. The system is incredibly poorly designed, using an IGBT typically meant for driving electric motors, directly connected through the EMI filter to the Type 2 port without a fuse. Any overvoltage in the grid or short circuits in the microgrid cause short circuits in the EMI filter, BCB, and the car’s battery, leading to damage of the varistor, which burns out the PCB and other components. All other manufacturers use fuses on the AC input of the OBC in their vehicles. Whoever designed this system should be fired immediately.
Due to its design, the Zoe faces numerous issues with charging, overheating during charging, and OBC charger failures. The worst part is that the OBC is so complexly designed that it is extremely difficult to service. The components are clumsily arranged in an aluminum box, with wires running through small holes in the box to the BCB, and every part of the charger is designed to make servicing difficult. This design approach by the engineers fails to consider sustainability or affordable repairs, and the replacement parts are unjustifiably expensive. Additionally, their parts are unjustifiably expensive. A new EMI filter costs around 1800€ (with the BCB adding 1500€ for the entire OBC assembly), while a used one ranges from 1000€ to 1400€. Buying a used part is very risky as there are several versions, and most of them are faulty (we bought one to fix the first case, but it didn’t fit and was defective). Statistically, the Renault Zoe is the vehicle with the most faults we haven’t been able to fix, and even authorized service centers haven’t been able to resolve many of the issues.
Nestabilna mreža najčešći je uzrok kvara OBC-a, osobito na Renault ZOE s Q pogonskim sustavom. Imali smo slučaj iz Srbije prije nekoliko mjeseci, koji nismo uspjeli riješiti jer je eksplozija uništila veliki dio PCB-a EMI filtera. Tada smo pretpostavili da je riječ o izoliranom incidentu. Međutim, nedavno smo dobili još jedan slučaj iz BiH s istim problemom. OBC se sastoji od FS200T12A1T4 Infineon HybridPACK1 IGBT-a, koji se više ne proizvodi, te EMI filtera. Sustav je nevjerojatno loše dizajniran – koristi IGBT koji se inače primjenjuje za pogon elektromotora, direktno spojen kroz EMI filter na Type 2 port bez osigurača. Bilo kakav prenapon u mreži ili kratki spoj u mikromreži uzrokuje kratki spoj na EMI filteru, BCB-u i bateriji vozila, što rezultira oštećenjem varistora koji uništava pločicu i ostale komponente. Svi ostali proizvođači imaju osigurače na AC ulazu OBC punjača u vozilu. Onaj tko je dizajnirao ovaj sustav, zaslužuje trenutačni otkaz.
Zoe, zbog svog dizajna, ima niz problema s punjenjem, pregrijavanjem tijekom punjenja i kvarovima OBC punjača. Najgore je što je OBC kompleksno dizajniran, što ga čini vrlo zahtjevnim za servisiranje. Komponente su nespretno raspoređene u aluminijskoj kutiji, s vodovima provučenim kroz male otvore u kutiji prema BCB-u. Svaki dio punjača je dizajniran tako da otežava servisiranje. Dizajnerski pristup francuskih inženjera zaslužuje kaznu, jer ne pridonosi održivosti niti omogućava prihvatljive troškove servisiranja. Osim toga, njihovi su dijelovi neopravdano skupi. Novi EMI filter košta oko 1800€ (BCB dodatno 1500€ za cijeli OBC sklop), dok polovni košta između 1000€ i 1400€. Kupnja polovnog dijela je vrlo rizična, postoji nekoliko verzija, a većina ih je neispravna (mi smo kupili jedan za rješavanje prvog slučaja, no nije odgovarao i bio je neispravan). Renault Zoe je statistički vozilo s najviše kvarova koje nismo uspjeli riješiti, a čak ni ovlašteni servisi nisu uspjeli otkloniti mnoge probleme.
Kataloški broj: 296G94241R
OEM: 2500€
EVC: 1400€
Zbog učestalih slučajeva vozila koja se nalaze daleko, uvrstili smo proceduru za reparaciju sa svim potrebnim dijelovima, čipovima i koracima, kako biste sami mogli popraviti pomoću EVC Academy:
When you plan pessimistically but it turns out the opposite, like the EU legacy plans to fight against electrification, which ended up being completely the opposite, a debacle. Two years ago, we had a plan to buy a faulty EV and restore everything, the motor and battery, for materials and documentation. By chance, we ended up getting an eGolf from Slovenia with 240,000 km on the clock, a worn-out electric motor, degraded battery, and broken CCS charging, for a lower price. The plan was to drive it hard and wear it out as quickly as possible so that it would break down, and we’d have something to work on. However, we’ve been driving it for 2 years now, and the damn thing just won’t part ways with the asphalt. From the looks of it, it won’t for a long time, so we gave up on waiting. We even tried putting a BMW N47 chain, a TSI turbo, a 2.0 water pump, a Renault clutch, an EGR, and a Mercedes DPF in the trunk as talismans, but none of them worked. We had to forcefully euthanize it at 257,000 km to take out the electric motor, analyze its condition, record the dimensions of the internal parts, and figure out how it’s possible that first-generation electric motors never need servicing. The first-generation eGolf is incredibly well-made; the only downside is its small battery and low range. It differs from the new generation in a few bearings; it doesn’t have the double-row bearing that the newer generations have, which tends to fail. The middle and output transmissions are on standard tapered roller bearings, and the rotor is on classic SKF ball bearings—6008 and another one. So, the motor that wasn’t over-engineered by 300 ‘expert engineers’ is currently five times more reliable than the newer generation. We completed the job together with a repair kit and a colleague from Schaeffler. The eGolf was back on the road in less than 2 days, once again driving with the original motor from 2012 for another 250,000 km. This is probably one of the most reliable electric VAG cars ever made, and maybe the last. It lacks a bigger range, but we are working with the Chinese on making a 60 kWh battery for this old model, which will elevate this Golf to a new level.
Motor code: EAG OEM price: €9600 Reman EVC: €1800
Kad planiraš pesimistično pa završi obrnuto, nešto kao EU legacy planovi da se bore protiv elektrifikacije a završi totalno suprotno, kao debakl. Tako nam je prije 2 godine bio plan da kupimo neispravan EV i restauriramo sve, motor i bateriju zbog materijala i dokumentacije. Tako slucajno dobijemo sa manjim cijenom iz Slovenije eGolf sa 240,000km na satu sa prozujanim elektromotorom, degradiranom baterijom i neispravnom CCS punjenjem. Plan je bio da ga vozimo i istrošimo čim prije da crkne pa da imamo šta raditi. Medjutim evo vozimo ga već 2 godine i neće dušman da se rastane od asfalta, a kako je izgledalo neće još jako dugo pa smo odustali od čekanja. Čak smo probali u gepek staviti lanac od bmw n47, turbinu TSI, vodenu pumpu od 2.0, kuplung od Renaulta, EGR, DPF od mercedesa ali niti jedan talisman nije pomogao. Morali smo ga prisilno eutanizirati na 257,000km da izvadim elektromotor i analiziramo stanje, popisemo dimenzije unutarnjih dijelova i da vidimo kako je moguce da elektromotori prve generacije uopce ne dolaze na servis. eGolf prve generacije je nevjerovatno kvalitetno napravljen, jedini nedostatak je mala baterija i nizak domet. Razlikuje se od nove generacije u par ležajeva, nemaju dvoredni lezaj kojeg imaju nove generacije koji inace i odlazi. Srednji i izlazni prijenos je na standardnim konusno valjkastim lezajevima a rotor na klasicnim SKF kuglicnim lezajevina, 6008 i jos jedan. Znaci motor koji nije izfilozofiran sa 300 misljenja “stručnih inzenjera” je za sada x5 pouzdaniji od novije generacije. Zahvat samo skupa prošli sa reparaturni setom i kolegom iz Schaeflera. eGolf je bio gotov za manje od 2 dana i ponovno vozi sa original motorom iz 2012 godine za sledecih 250,000km. Ovo je vjerovano jedan od najpouzdanijih VAG strujicq koji su ikad napravili, mozda i zadnji. Nedostaje mu veci domet ali radimo sa kinezima na izradi 60kWh baterije za ovaj stari model koji ce ovog golfa dignuti na novi tron.
Toyota Auris Hybrid – A Case of Battery Degradation at 246,000 km
Battery degradation is expected in high-mileage hybrid vehicles, but this case stands out—not in a Tesla or even a Nissan Leaf, but in a Toyota Auris Hybrid. At 246,000 km, this battery exhibited 82% degradation, with more than half of the battery system showing signs of permanent damage, likely due to prolonged overheating and limited thermal management in the original design.
While the battery was reported as unopened, there are indications that it may have been serviced before—such as a clean cooling fan and four marked cells. In our experience, we often come across “never opened” batteries that have, in fact, been repaired or reconditioned multiple times, including cell replacements, rearrangements, or regeneration, yet are still presented as original and untouched. This contributes to the perception that these batteries consistently last 500,000 km, even though many have undergone previous interventions.
Real-World Battery Longevity in Hybrids
From the cases we’ve examined, we have observed that:
Extreme battery degradation (50%) typically begins around 150,000-180,000 km.
Only one verified case of an original, untouched battery exceeded 300,000 km—though by 150,000 km, it had already lost 50% of its original capacity.
Despite degradation, Toyota’s replacement battery pricing is notably lower than that of European hybrid models, with a new unit from the service center costing around €2,200—a fraction of the €10,000-€30,000 range seen in some other hybrids.
Efficiency Considerations
Given the extent of degradation and the hybrid system’s reliance on battery functionality, an interesting question arises: Would the Toyota Auris achieve better efficiency without the added complexity of the hybrid system once the battery reaches this level of wear? While hybrids offer fuel savings when the battery is healthy, high degradation levels may impact overall efficiency, raising questions about long-term cost-effectiveness for owners.
“Toyota hybrid batteries never fail” “Don’t listen to EV Clinic, they think everything is bad” “Batteries last over 500,000 km in all Toyotas” “The warranty is 10 years” (they forget to mention it’s 180k km) “Those guys are amateurs”
Understanding Toyota Hybrid Battery Longevity & Maintenance
Many drivers rely on real-world data rather than marketing claims when assessing vehicle reliability. In our work repairing hybrid battery systems, we also communicate with authorized service technicians, which gives us insight into common issues and long-term performance trends. Over the years, we have noticed misconceptions and misinformation circulating in Toyota hybrid communities, so we’ll address some of the most frequent questions we’ve received.
We have always stated that among hybrids, Toyota is the most reliable choice, making it a better alternative than diesel. However, compared to electric vehicles (EVs), the hybrid system has limitations—not all EVs are better, but Toyota’s NiMH (Nickel-Metal Hydride) battery system has design challenges that impact longevity.
Battery Design & Common Issues
The Toyota hybrid battery pack features a passive cooling system, with airflow-dependent temperature regulation. The middle section of the battery is prone to overheating, as it lacks direct thermal management. In contrast, some hybrid models, such as the Mitsubishi Outlander PHEV, integrate a chiller system from the air conditioning unit to improve cooling efficiency.
Key design factors that affect battery longevity include:
Limited monitoring & balancing – The Battery Management System (BMS) monitors every 5th or 6th cell but does not actively balance the middle modules, leading to uneven aging.
Minimal temperature sensors – The system uses only 2-3 temperature sensors, with no redundant protection in case of airflow blockage.
Variable degradation rates – Some batteries experience cell overheating as early as 80,000 km, while others last up to 180,000 km before showing similar symptoms.
Real-World Battery Usage & Repair Trends
Some owners report driving their Toyota hybrids up to 750,000 km on the “original” battery pack. However, our experience servicing hybrid battery systems shows that in many of these cases, the pack has undergone multiple repairs and cell replacements, but since the battery casing remains unchanged, it is still considered “original.”
Toyota’s advantage is that they offer replacement batteries at a relatively low cost—around €2,000 for a 1 kWh battery pack. While this is significantly cheaper than European hybrid models, it is still around 8 times more expensive per kWh than an EV battery, which typically costs €250 per kWh.
In fleet usage, such as taxis, we have observed:
By 200,000 – 250,000 km, batteries often arrive with 8-15 degraded cells, which is more than half of the pack.
Some batteries show signatures from multiple mechanics at 400,000 km, indicating previous repairs and interventions.
Some drivers manually clear error codes via Bluetooth OBD tools, allowing them to continue driving despite deteriorating battery health, until the car eventually stops functioning.
Myths vs. Reality
One of the most persistent myths surrounding Toyota hybrids is the belief that battery degradation is never an issue and that hybrid batteries last “millions of kilometers” without problems. While Toyota’s system is designed for longevity, real-world data shows that battery degradation does occur and affects fuel savings and overall efficiency over time.
Preventive Measures for Extending Battery Life
To maximize the lifespan of a Toyota hybrid battery, preventive maintenance is key:
Use the air conditioning in the summer to direct cool air towards the rear passenger footwell—this helps the battery draw in cooler air for better temperature regulation.
Disassemble and clean the battery cooling channels every 50,000 km—dust and debris can clog the cooling system, leading to increased operating temperatures and premature cell degradation.
Avoid prolonged high-temperature exposure, as a single overheating event can cause permanent battery damage, regardless of the total mileage.
While Toyota’s hybrid system remains one of the most cost-effective hybrid solutions available, long-term maintenance and battery management play a crucial role in ensuring optimal efficiency and reliability.
Conclusion:
Their batteries do fail
They are easily repairable
Parts are very accessible
Batteries are cooked by 150k km
Preventive maintenance is a no-brainer
Toyota has the most sustainable hybrid system of all
Battery is poorly designed
Battery has a high tolerance for failure, doesn’t trigger an error
Again, the “worst of both worlds” applies to the 2018 BMW G30 eDrive Hybrid, whose complete battery pack is so worn out that repair isn’t feasible without replacing all modules. This vehicle has only covered 150,000 km and first error popped up at 104,000 km that battery is in defect immediately after warranty end, yet it requires a new 9 kWh battery pack costing €11,000 with tax and labor. Despite active thermal control, the cells have degraded and inflated under high current rates, where a small battery supports a large power-train. Each kilometer driven in EV mode damages the battery pack four times faster than the larger battery packs found in full EVs. Hybrids are truly unsustainable and cannot be a part of any eMobility narratives. So, in addition to the pollution from the fossil engine, oil changes, and other maintenance, you also have waste production from poorly designed weak battery systems.
Problem is not withinn quality of cells but the design of the system. Even if you integrate highest quality cells from future year 2155, this system will fail due semifinished design. Small cells with small current rate and capacity cant support heavy powertrain system too long. Charge and discharge cycles of 2000 will wear out in 50,000 and 100,000km. So you understand why it has only 100k warranty on battery pack. BMW is one of the worst Hybrid systems we have ever seen and they are mostly filling our inbox with repair requests.
This vehicle serves as yet another example of why some hybrid systems struggle to offer a sustainable long-term solution. After monitoring internal reports and Nissan owner groups, we have observed that the so-called “self-charging hybrid” frequently experiences failures.
One particular case involved an electric generator motor failure at just 10,000 km—and this is not an isolated incident. While conceptually, this system is close to what could be an ideal hybrid design—where the internal combustion engine (ICE) acts solely as a generator to charge the battery and power the drive motor—the real-world execution does not align with expectations.
Technical Concerns & Failure Reports
This system utilizes:
A three-liter turbocharged ICE that runs a Denso PMSM electric generator.
A third electric motor for propulsion.
A 2.2 kWh air-cooled battery, which is relatively small for an electrified system and lacks home-charging capability.
Key Issues Identified:
A new generator electric motor costs €11,000 (excluding installation).
A second drive motor also reportedly fails within the same 15,000-30,000 km range.
Replacement cost of the drive motor is €17,000, excluding labor.
This presents a significant cost burden for owners, as in addition to these potential electric motor replacements, the vehicle still requires regular ICE maintenance, including:
Oil changes
Turbo maintenance
Belt replacements
Filter replacements
Failure Diagnosis & Potential Causes
From reports of failed generator motors, the primary fault appears to be insulation breakdown, which can lead to internal short circuits or stator overheating. The suspected cause is vibrations and thermal expansion from the ICE, which may contribute to cracking of the stator insulation.
Notably:
Bearings are in good condition.
There is no evidence of coolant or moisture penetration.
Hairpin stator design appears vulnerable to mechanical stress over time.
This raises the question: Can these stators be repaired using traditional round-wire winding technology, or is full replacement the only option?
Cost vs. Functionality—Is This System Sustainable?
Given the high failure rates and replacement costs, this system appears to place a significant financial burden on owners. With an ICE engine, two electric motors, and a hybrid battery all requiring maintenance and potential replacement, the overall cost structure is considerably high.
While the battery price is unclear, Nissan battery replacements have historically started at €10,000 or more. If that remains the case, the total cost of maintaining this system far exceeds its expected savings.
Final Thoughts
For service centers and repair specialists, this hybrid system may present interesting engineering challenges, but for owners, the financial implications are considerable. The long-term cost-effectiveness and sustainability of this system should be carefully evaluated before purchase.
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