Can a Car Manufacturer Call a Renewable Battery Warranty an “8-Year/100,000-Mile” Warranty?
When shopping for a hybrid or electric vehicle, one of the most heavily advertised selling points is the battery warranty. A common claim in brochures, websites, and sales pitches is the "8-year/100,000-mile warranty." This promise gives buyers peace of mind that their most expensive component—the high-voltage battery—is protected for the long haul. But what happens when that warranty is not truly continuous for 8 years, but rather structured as a series of renewable 1-year terms?
Is it fair—or even legal—for a manufacturer to call that an “8-year warranty”?
Understanding the Issue: What’s Being Promised vs. What’s Delivered
A “8-year/100,000-mile warranty” implies continuous coverage for either 8 years or 100,000 miles (whichever comes first). Most consumers reasonably interpret this to mean that the battery is protected for that entire period without interruption, so long as they don’t exceed the mileage cap or abuse the product.
However, some automakers structure the warranty as a series of renewable one-year coverage periods. These renewals may be contingent upon annual inspections, battery performance thresholds, or specific service requirements.
If any of these requirements are missed—even by accident—the warranty may be denied by the manufacture for the entire remaining term, leaving the vehicle uncovered despite still being under the original 8-year/100,000-mile timeline.
Can Manufacturers Advertise It as an 8-Year Warranty?
Legally, manufacturers must follow truth-in-advertising laws and warranty disclosure rules, including the federal Magnuson-Moss Warranty Act. This law requires that warranties be clearly and fully disclosed in consumer-friendly language, and it prohibits deceptive practices.
If a warranty is not truly continuous, but instead requires annual requalification, then advertising it as a blanket “8-year/100,000-mile” warranty may be misleading unless the conditional structure is clearly and prominently disclosed.
So, the answer is:
No, a manufacturer cannot use the “8-year/100,000-mile” label — they must clearly explain that it’s a series of renewable 1-year terms and disclose all the conditions required to maintain coverage.
Failing to do so could subject the manufacturer to:
Consumer complaints and lawsuits (including class actions),
Federal Trade Commission (FTC) enforcement, and
Reputation damage, particularly among informed EV buyers.
Why It Matters to Consumers
The key issue is expectation vs. reality. A consumer expecting 8 years of uninterrupted coverage may:
Miss an annual inspection, unintentionally voiding the warranty,
Fail to understand that capacity loss below a certain threshold could terminate coverage early, or
Assume they’re protected only to find out too late that they’re not.
Given the high cost of battery replacement—often $10,000 or more—this can result in serious financial harm.
What Consumers Can Do to Protect Themselves
Request and read the full warranty booklet before purchase—not just marketing material.
Ask direct questions, such as:
Is the 8-year warranty continuous or broken into renewable terms?
What actions must I take each year to keep coverage valid?
Look for phrases like “capacity retention tests,” “annual inspection,” or “renewal conditions”.
Document all required inspections or maintenance, and keep detailed service records.
Report unclear or misleading advertising to the FTC or your state attorney general.
Conclusion
While it may be common for a manufacturer to call a renewable series of warranties an “8-year/100,000-mile” warranty, doing so without clear and full disclosure is misleading at best—and potentially deceptive under federal law.
Consumers should not have to be lawyers to understand their car warranty. Transparency matters, especially when it comes to high-cost EV components. If a warranty is conditional, it should be clearly labeled and prominently described that way. Until then, buyers must read the fine print—and ask tough questions—before signing on the dotted line.