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| LG batteries from Nanjing apparently have a shorter lifespan than Panasonic batteries. |
ZAGREB – A leading European electric vehicle battery repair specialist is raising serious questions about the long-term durability of a specific battery type used in thousands of Tesla Model 3 and Model Y cars, warning of significantly reduced lifespans and costly, unfixable failures.
EV Clinic, a renowned Croatian repair shop specializing in high-voltage systems, has published a damning report based on its workshop data. The report centers on the LG Energy Solution NCM811 battery packs supplied from Nanjing, China, which were installed in certain Tesla vehicles during production peaks in 2021 and 2022.
A Stark Divide in Mileage Expectations
The core of EV Clinic’s concern is a dramatic disparity in operational lifespan. According to their extensive field data, the widely-used Panasonic battery packs (also found in Teslas) are consistently reaching their end-of-life stage after approximately 400,000 kilometers (roughly 250,000 miles).
In contrast, their analysis suggests the affected LG NCM811 packs are showing critical degradation much earlier, often providing just over 250,000 kilometers (about 155,000 miles) of usable life—a reduction of nearly 40% compared to the Panasonic units.
The Root Cause: "Exceptionally High" Internal Resistance
EV Clinic technicians pinpoint the issue to the fundamental health metric of a battery cell: internal resistance. This resistance, measured in milliohms (mΩ), indicates how easily current flows within a cell. Higher resistance leads to heat buildup, voltage sag, and accelerated aging.
Their findings reveal a shocking baseline discrepancy. A new, healthy Panasonic cell typically registers around 10 mΩ. However, EV Clinic reports that brand new LG NCM811 cells from the Nanjing factory are measuring 28 mΩ or more upon delivery—a level that would be flagged as a potential defect in other battery ecosystems.
“The internal resistance of the LG cells, even from new, is at a level we associate with failing cells in other packs,” explained a senior EV Clinic diagnostician. “This sets a very poor starting point for long-term durability.”
A Repair Shop's Dilemma: "90% Unrepairable"
The problem compounds when these batteries fail. EV Clinic states that in over 90% of cases involving faulty LG packs brought to their facility, conventional repair—swapping out individual bad cells—is impossible.
The issue is a cascading effect of high resistance. It rarely affects just one cell. Instead, multiple cells exhibit extreme resistance values, destabilizing the entire module. Replacing a handful of cells doesn’t solve the underlying imbalance, often leading to immediate failure of the new cells. Consequently, EV Clinic says the only reliable solution is a complete replacement of the battery pack, frequently opting for a refurbished Panasonic unit as a swap.
[Embedded Tweet: EV Clinic shared detailed technical data on the internal resistance findings, which can be viewed here: https://x.com/evclinic/status/1994876173277335745]
Financial Toll on Repair Business
The situation is taking a significant financial toll on independent repair shops willing to tackle these complex packs. EV Clinic currently estimates it loses over $20,000 per month in labor and resources testing LG batteries only to determine they are beyond economical repair. Due to this sunk cost, the workshop has now begun charging a dedicated fee solely to assess whether an LG battery pack has any hope of repair—a practice they don’t apply to other battery types.
In its starkest assessment, EV Clinic describes the performance and repairability of these Chinese-made LG NCM811 cells as "catastrophic."
Context and Unanswered Questions
It is crucial to note that this report is based on the specific experience of one repair shop, albeit a highly respected one in the European EV community. Battery longevity is influenced by a multitude of factors, including charging habits, climate, and software management from the vehicle's Battery Management System (BMS).
Neither LG Energy Solution nor Tesla has publicly commented on these specific claims from EV Clinic. The report likely pertains to a specific production batch or chemistry iteration of the NCM811 cells, not necessarily all LG batteries in Teslas.
For owners of affected Model 3 and Y vehicles, this report highlights the importance of monitoring battery health metrics. It also underscores a growing challenge in the EV ecosystem: the vast difference in repairability and longevity between battery suppliers, which can have major implications for long-term ownership costs and sustainability.
As the used EV market matures, independent data like this from frontline technicians will become increasingly vital for consumers and the industry alike, pushing for greater transparency and durability in battery design.