Why a Cheaper EV Battery Could Cost You Double in the Long Run

Repair Shop Sounds the Alarm

A European repair shop reports that it has seen high failure rates when repairing Chinese-made LG NCM811 battery packs in certain Tesla Model 3/Model Y vehicles. Specifically, greater than 90% of these Chinese-made LG battery packs cannot be repaired at the individual cell level. The degradation within failing modules stands beyond what can be restored. 

Compared to batteries made by other manufacturers, EV Clinic has observed significant differences between LG battery packs manufactured at the LGES Nanjing facility in China, compared to similar packs made by Panasonic in the US. The data collected by EV Clinic indicates that the LG packs begin their service life at or near the time that a comparable pack from Panasonic would begin to degrade.

The Numbers Tell a Troubling Story

Panasonic cells generally measure at a low internal resistance of 10 milliohms (mΩ), whereas brand-new LG cells from the Nanjing plant measure at an average of 28 mΩ, which is where Panasonic packs are showing signs of potential failure. Further, when technicians evaluate the performance of a failed LG module with 46 cells, it is common to see 15 of them exceed 100 mΩ of internal resistance, with the remaining 30 cells exhibiting resistances of 50 mΩ or higher. The widespread failure of the cells in these packs makes repair of the pack economically unfeasible.

The implications of the reduced service life of Chinese-made LG battery packs extend to the expected vehicle mileage of owners. From the technicians’ experience, Panasonic battery packs are expected to last until they reach 250,000 miles. However, the same technicians estimate that the Chinese-made LG battery packs will likely last until they reach approximately 155,000 miles, a difference of 37% less than the estimated life expectancy of the Panasonic battery packs.

Upfront Savings Versus Lifetime Value

While Chinese-made batteries may provide a lower upfront price for consumers in some instances, the shorter service life skews the economics significantly. A replacement battery pack from LG will cost approximately $18,000, whereas the cost of replacing a battery pack from Panasonic will be approximately $9,500.

Batteries produced in Europe and America exhibit longer service lives, even though there are higher initial manufacturing costs. Single-cell failures occur at 150,000 miles in the domestically produced Panasonic batteries, and those packs continue to be repairable. The Chinese made LG batteries exhibit simultaneous failures in many of their cells, making most of their modules unreparable. Consumers who plan to keep their vehicles for a long time should pay the premium for non-Chinese battery chemistries.