A wave of complaints has erupted over power battery performance in GAC Aion’s Aion S vehicles fitted with lithium iron phosphate (LFP) cells made by CALB, with owners reporting battery swelling, leakage, and insulation-related failures.
The issue came to broader attention after state media highlighted the problem in a July 14 report, which did not name CALB directly. However, subsequent coverage and responses from both companies were widely interpreted as pointing to the battery supplier.
According to the report, complaints appearing on public consumer platforms since the start of 2026 involve commercially operated vehicles using CALB’s 177-Ah battery cells. Owners and investigators described symptoms including cell bulging, fluid leakage, and faults tied to battery insulation. Third-party inspection documents submitted by some vehicle owners indicated that external causes—such as crashes or water immersion—could be ruled out, suggesting internal manufacturing defects.
Separate reporting also cited a sharp rise in grievances within a short window from July 1 to July 18, with cases involving reduced driving range alongside swelling and leakage. The failures were described as clustering within a mileage band of roughly 150,000 kilometers to 300,000 kilometers—an interval that many commercial operators said overlaps with, or immediately follows, the end of warranty coverage.
One owner in Suzhou described a system failure after about 230,000 kilometers. The after-sales dealership reportedly acknowledged a battery quality defect but refused full compensation on the grounds that the vehicle exceeded an earlier warranty threshold. The owner said the store required out-of-pocket payment of about 80,000 yuan (around $11,811) to replace the entire battery pack.
In response to mounting attention, GAC Aion and CALB both released announcements on July 18.
GAC Aion said its preliminary investigation confirmed that some Aion S vehicles equipped with CALB’s 177-Ah batteries and used for commercial operations experienced battery failures. The automaker said it is extending the battery warranty for affected vehicles from “8 years or 150,000 kilometers” to “8 years or 300,000 kilometers.” The company also pledged to strengthen remote monitoring of battery data, proactively contact customers when anomalies are detected, and provide free inspection, free repair, or free battery pack replacement for eligible cases.
CALB said it takes the matter seriously and has begun maintenance actions through GAC Aion’s 4S retail service network. The company stated that owners can approach its service outlets for free inspection and repair and that it will take responsibility for product quality throughout the lifecycle.
A battery repair engineer in Tianjin, who declined to be named, told state media that he has handled more than 30 cases involving the problematic batteries across the Beijing–Tianjin–Hebei region. He suggested the root cause likely lies in battery design and argued that manufacturers may have shortened validation testing schedules amid intense competition.
The dispute unfolds as China tightens battery safety oversight. On July 1, two mandatory national standards for electric vehicles took effect, including new requirements for power batteries to prevent “fire and explosion” after thermal runaway in a single cell. Industry observers noted that while the stricter rules apply primarily to newly approved vehicle models, existing vehicles on the road continue to be governed by enforcement under older regulations—leaving room for disagreements about responsibility when failures arise after warranty periods.
