Made-in-China battery packs are bad!

Media hype around “Made in China” battery systems being the “best” has never been confirmed in real-world practice.

We are raising serious concerns about Tesla Model 3/Y LG NCM811 battery packs (LGES Nanjing), which show extremely high failure rates and a noticeably shorter end-of-life compared with Panasonic NCA packs (Made in USA).

In over 90% of the cases we receive, cell-level repair is not possible on LG packs. The cell degradation within affected modules is far beyond anything that could be restored. The issue is rarely a single bad cell—most failing modules contain multiple cells with extremely high internal resistance. Out of 46 cells, it is common to find 15 cells over 100 mΩ ACIR, and the remaining 30 cells above 50 mΩ ACIR.

Given these patterns, adjacent series groups measured in parallel modules often show resistance values already above acceptable limits. This means that even if we replace the faulty cells with used, matching donor cells (never with new cells), the remaining weakened cells are likely to fail in a cascade. This makes the repair operationally unsustainable, as the entire pack is clearly nearing end-of-life, exposing us to extremely high warranty and labor costs.

Another unknown is this:

If one out of four modules is badly degraded, what are the chances that replacing a single module will result in a stable pack, and for how long?

Is it realistic to expect another 100,000 km of trouble-free use after replacing one module?

Most likely not.

At this moment, during ongoing experimental testing with real customers experiencing LG failures, we are losing over €20,000 per month in operational time while investigating whether LG’s Chinese NCM811 systems can be sustainably repaired. At this stage, we can confidently say: the cells are, to put it mildly, catastrophic. Panasonic has mostly single cell falire at 250,000km, and it is repairable, where LG hasmultiple cell failur.

For reference:

• A healthy Panasonic cell typically shows ~10 mΩ, while a new LG Nanjing cell starts around 28 mΩ.

• A failing Panasonic cell reaches ~28 mΩ, which is what LG cells measure when brand new.

It is extremely difficult to explain this complexity to customers.

The only alternative we can responsibly offer—although very rarely—is replacing the entire battery pack with a used Panasonic pack from the secondary market.

This brings us to a fundamental question:

Where does the media hype come from claiming that Chinese-made cells are “better”?

In practice, the best Li-ion cells are made in Europe (LG Chem, Samsung SDI) and the USA (Panasonic).

China’s strength is limited primarily to LFP technology, but Blade-format LFP packs are entirely non-repairable researched by independent institutes.

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Important Notice for Tesla owners with Chinese LG packs

Due to extremely high operational losses, we must introduce an experimental “repair check feasibility” fee to determine whether repair is even possible.

If the pack is deemed non-repairable, the only options are:

1. Replacement with a used Panasonic pack

2. Full pack replacement at a Tesla Service Center

When supplying used Panasonic packs, we do not guarantee range, charging speed, or long-term capacity.

Warranty covers functional defects—not degradation or reduced range.

This article also serves as an official disclaimer.

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Reference Data

Part number: 17000012-00-B

OEM price: €15,355 (excl. tax, EPC)

EVC repair check: €1,200 non-refundable (remove/assemble)

Waived if repair is possible

EVC full repair: €5,500 (excl. tax)

EVC Panasonic swap: €8,000 (excl. tax)

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Estimated End-of-Life (EOL)

• Panasonic packs: ~400,000 km

• LG NCM811 (China): ~250,000 km