Exclusive: Nearly 4,500 Teslas in Korea report battery errors, risking subsidy loss

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Exclusive: Nearly 4,500 Teslas in Korea report battery errors, risking subsidy loss

Published: 14 Oct. 2025, 06:00 Updated: 14 Oct. 2025, 19:35

SARAH CHEA
[email protected]

Audio report: written by reporters, read by AI

Tesla EVs are charged at a Supercharger in central Seoul. [YONHAP]

Nearly 4,500 Teslas in Korea have experienced battery system malfunctions that prevent charging, with over half replaced with reused batteries rather than new ones, fueling consumer outrage over the EV giant’s failure to uphold accountability.

Korea’s Environment Ministry has formally demanded a resolution, warning that continued inaction could lead to the suspension of government subsidies.

[단독] 한국 판매 테슬라 4500여대에서 배터리시스템 오류…절반은 ‘재제조 배터리’로 AS

According to data acquired by the Korea JoongAng Daily, a total of 4,351 Tesla EVs have experienced 4,637 cases of the BMS_a079 error since 2017 in Korea, based on data submitted by Tesla Korea to Democratic Party lawmaker Park Sang-hyuk that has not been made public. Of them, 245 cars suffered the same failure twice, while 19 units reported it three times. One vehicle was found to have experienced the error four times.

By model year, roughly 65 percent of the cases, or 2,991, occurred in 2021 models. Among them, 1,944 were Model Ys, accounting for 22 percent of that year’s total Model Y sales. For the Model 3, 1,047 cases were reported, representing 12 percent of its 2021 sales.

BMS_a079 alert in Tesla reads ″Unable to charge. Maximum charge level reached,″ in a photo shared by a Korean owner in an online community. [SCREEN CAPTURE]

The BMS_a079 error, accompanied by the message “Unable to charge — maximum charge level reached,” occurs when Tesla’s Battery Management System (BMS) detects a fault within the high-voltage battery. To prevent battery overload and reduce the risk of fire, the system limits the maximum charge to 50 percent, which may make owners face severe restrictions in daily driving and risk significant financial losses when reselling the vehicle.

The BMS, often described as the “brain” of an EV, monitors critical factors such as voltage and temperature to optimize battery performance and alerts users of any anomalies that require prompt attention.

What has fueled even greater consumer backlash is the fact that, of the 4,637 cases that experienced the error, more than half, or 2,406, were replaced with so-called "remanufactured batteries" rather than brand-new batteries.

The remanufactured units are assembled using salvageable cells extracted from defective or returned Teslas, which are then repaired, tested and repackaged at the factory. However, numerous cases have been reported of reduced driving range or recurring failures after replacement, leading many owners to view these batteries as undesirable.

Tesla's new Model Y Juniper, which launched in Korea in April. [TESLA]

Tesla's Model Y, codenamed Project Juniper [SCREEN CAPTURE]

“We have requested a clear response from Tesla Korea regarding the issue, but have yet to receive one,” an official who handles EV subsidy programs, told the Korea JoongAng Daily.

“If the company continues to remain unresponsive, we will have no choice [but to consider suspending subsidies.] We cannot justify providing public funds for vehicles that disadvantage consumers.”

Consumers have been calling for a voluntary recall or free battery replacements from Tesla, but the company has yet to issue any formal response. Tesla’s battery warranty covers eight years or 160,000 kilometers (99419 miles), but once this period expires, owners are left to shoulder repair costs that can exceed 30 million won ($22,000). On Korea’s largest Tesla online community, which has over 430,000 members, hundreds of posts detailing battery-related errors have been shared, with some owners reportedly engaging in collective action.

A petition was filed on the National Assembly’s public petition platform in August, calling for an investigation into battery defects in Tesla’s EVs and demanding a full recall at no cost to owners. The petition garnered signatures from some 14,008 people.

Citizens United for Consumer Sovereignty, a civic group, in September also issued a statement urging Tesla Korea to clearly identify the root cause of the defects and initiate a full-scale recall. The group further called on the Ministry of Land, Infrastructure and Transport to conduct a prompt and thorough investigation.

Despite its robust sales in the Korean market, Tesla has been facing consumer criticism due to insufficient clarity in its after-sales policies. Since entering Korea, Tesla Korea has sold a total of 134,429 cars as of 2025, and its annual revenue more than doubled from 716.2 billion won in 2020 to 1.7 trillion won last year.

In the first half of this year, the Model Y emerged as the best-selling EV in the country, with 15,432 units sold — surpassing Kia’s EV3 that sold 12,299 units and Hyundai Motor’s Ioniq 5 with 6,937 unit sales.

Despite this commercial success, Tesla Korea operates only 14 service centers nationwide, often leading to long wait times for repairs. The average repair time for Tesla’s BMS issues was 23.4 days, compared to 13 days for Integrated Charging Control Unit failures in Hyundai EVs. In one extreme case, a Tesla BMS repair took 926 days — more than two and a half years.

BY SARAH CHEA [[email protected]]