Here's a story that'll make Tesla Inc. (TSLA) owners with certain battery packs a bit nervous. A European service provider called EV Clinic, based in Croatia, is sounding the alarm about a serious problem with Model Y and Model 3 vehicles equipped with LG Energy Solutions' China-made NMC (Nickel Manganese Cobalt) batteries. According to the repair shop, these battery packs are experiencing what they're calling "catastrophic" failures—and they're essentially impossible to fix.

The Problem Goes Deeper Than Bad Cells

In a post on X this Monday, EV Clinic laid out the situation in stark terms. "In over 90% of the cases we receive, cell-level repair is not possible on LG packs," the company explained. We're not talking about a single faulty cell that you can swap out and call it a day. The degradation appears to be widespread across entire modules, making the damage far beyond what's restorable.

The technical details make the situation clearer. EV Clinic found that LG cells manufactured in Nanjing show extremely high internal resistance when compared to batteries made by Panasonic Holdings Corp (PCRFF) (PCRHY). How bad is it? "A failing Panasonic cell reaches ~28 mΩ, which is what LG cells measure when brand new," the clinic shared. In other words, a brand-new LG battery has the same resistance as a Panasonic battery that's already failing. That's not a great starting point.

The financial impact on the repair shop itself is substantial. "At this moment, during ongoing experimental testing with real customers experiencing LG failures, we are losing over €20,000 (approximately $23,200) per month in operational time," the company said. That's real money being burned trying to solve a problem that, in most cases, can't be solved with repair work.

Lifespan Differences Are Dramatic

EV Clinic shared some eye-opening longevity estimates. They peg the estimated end-of-life for Panasonic battery packs at approximately 400,000 km, while the LG NCM811 units from China clock in at around 250,000 km. Panasonic batteries typically experience single-cell failure at 250,000 km—right around where the LG packs are calling it quits entirely.

The workshop says explaining this situation to customers is difficult, which makes sense when you're essentially telling someone their relatively new EV needs a complete battery replacement. In extreme cases, EV Clinic has resorted to replacing LG battery packs with used Panasonic ones, which tells you something about how severe the problem is.

Tesla did not immediately respond to MarketDash's request for comment on the findings.

Tesla's Battery Strategy Is Evolving

The timing is interesting because Tesla has been busy diversifying its battery supply chain. The company recently filed a patent with the USPTO detailing new battery chemistry that promises better performance, efficiency, and thermal management with minimal degradation. The patent uses a different solvent approach, and the results look impressive: the battery with the new chemistry retained up to 99% capacity even after 3,500 hours of use.

Tesla has also been making moves on the supplier front. The company signed a $2 billion deal with South Korea's Samsung SDI to supply energy storage system (ESS) batteries. This comes as Tesla's Energy Storage business has been booming—the company reported 44% growth in that segment during its Q3 earnings call, generating over $3.4 billion in revenue.

These developments suggest Tesla is actively working on battery improvements and partnerships, which might be welcome news for owners concerned about the LG battery situation. Whether these new initiatives will address the existing problems with China-made LG batteries remains to be seen.

Price Action: TSLA shares rose 0.33% to $431.55 during pre-market trading, according to market data.