When battery wear constitutes a defect, how to prove it, and what rights you have against retailers and manufacturers.
If your electric car's battery loses capacity unusually quickly, this could constitute a defect, giving rise to claims against the dealer and manufacturer. The crucial point is distinguishing between normal aging and a genuine defect. This article explains when claims are valid and how to enforce them.
Battery degradation: what's normal and what's not
Every traction battery loses capacity over time. This process is called degradation and is initially completely normal. It occurs somewhat faster in the first few kilometers, after which the loss slows down considerably.
As a rough guide, an average capacity loss of about one to two percent per year is expected under normal use. Many electric cars still retain around 90 percent of their original capacity even after 160,000 kilometers. A vehicle that ages significantly faster, for example with less than 80 percent remaining capacity despite being young and having moderate mileage, is an exception to the norm.
This distinction is legally crucial. Normal, age-related degradation is not a defect, but rather expected wear and tear. However, noticeably accelerated aging can indicate a defect.
Is your battery losing range faster than you expected? Have it checked to see if the degradation is still normal or if it already indicates a defect.
When is battery wear considered a defect?
Whether a battery is defective is determined by Section 434 of the German Civil Code (BGB). A vehicle is defective if it does not possess the qualities a buyer can expect. In the case of a battery, this means it must deliver the capacity and performance that is typical for its age and mileage and that the manufacturer has promised. A material defect is primarily considered in three situations.
- Accelerated degradation: The battery loses capacity significantly faster than would be expected given its age and usage.
- Insufficient range: If the range drops significantly below the advertised WLTP value due to capacity loss, the same rule applies as in the case of a pure lack of range.
- Technical defect: Individual cells or modules fail, or the battery management system malfunctions.
We explain in detail how the threshold for range works exactly, especially the limit of more than ten percent deviation, on our page about Reversal of an electric car purchase due to insufficient range.
Whether your capacity loss exceeds the threshold for a defect can only be assessed on a case-by-case basis. We will classify your battery case from a legal perspective.
Warranty against the retailer: Your legal rights
If there is a battery defect, you initially have statutory warranty rights against the dealer from whom you purchased the vehicle. These rights are tiered.
- Subsequent fulfillment: You can request rectification or replacement, such as the exchange of defective modules.
- Resignation: In the event of a significant defect, you return the vehicle and receive the purchase price less a usage fee.
- Reduction: They keep the vehicle and demand a partial refund of the purchase price.
- Damages: Additional costs, such as for an expert opinion, can be claimed as reimbursement.
These rights typically last for two years after delivery of a new car. An important advantage: When purchasing from a dealer as a consumer, it is presumed during the first year after delivery that any defect shown was already present at the time of delivery (§ 477 BGB). During this period, the dealer must prove otherwise.
Which option is best for you depends on your age, mileage, and the extent of the capacity loss. We will review your options and assess your needs.
Manufacturer's warranty on the battery: what it offers and where the pitfalls lie.
In addition to the statutory warranty, most manufacturers offer their own warranty on the traction battery. This is typically eight years or 160,000 kilometers, whichever comes first. During this period, manufacturers generally guarantee that the usable capacity will not fall below approximately 70 percent.
This guarantee is a voluntary contractual commitment and goes beyond the statutory warranty. If the capacity falls below the agreed threshold within the guarantee period, a warranty claim may be valid, which the manufacturer will fulfill by repairing or replacing modules or the battery. However, the terms and conditions should be carefully reviewed.
- Terms of Use: Many warranties require adherence to specific charging and maintenance guidelines. Failure to do so may limit the warranty.
- High threshold: The warranty only applies below approximately 70 percent capacity. A noticeable but minor loss is therefore often not covered, but can still be a warranty claim.
- Proof required: The capacity value must be verified, usually by measuring the battery's state of health.
Warranty and guarantee are not mutually exclusive. It is often worthwhile to explore both options, as legal rights against the retailer can apply even if the manufacturer's warranty does not yet cover the loss.
Are you unsure which course of action is best in your case? We will examine warranty and guarantee options simultaneously and choose the most promising course of action.
How to prove a battery deficiency
The proof determines the success. The battery's state of health, or SoH for short, is crucial.
- SoH report: Specialized testing procedures determine the remaining capacity and compare it with the value that would be expected for age and mileage.
- Comparison with reference values: If the remaining capacity is significantly below the usual range, this is a strong indication of a shortage.
- Own documentation: Record ranges, charging behavior, and any noticeable changes over an extended period.
It is important to clearly distinguish this from normal aging. Only when the degradation significantly exceeds the usual level can a defect be established. A qualified expert opinion is usually the crucial element in this.
Before contacting the retailer, the condition of your battery should be reliably documented. We'll tell you what evidence counts in case of a dispute.
Further battery and software use cases at a glance
Battery problems manifest in various forms. Besides simple degradation, there are other scenarios that raise their own legal questions, which this section addresses step by step.
- Range reduction due to software update: Subsequent throttling without your consent may trigger claims for damages.
- Reduced charging power: If the vehicle consistently charges slower than advertised, this may indicate a defect.
- Plug-in hybrids: Even with plug-in hybrid vehicles, the electric range often differs significantly between the test bench and the road.
Tesla often experiences software reductions and an increased frequency of defects, which we discuss separately on our website. Tesla defects Rogert & Ulbrich has dealt with the legal mechanics behind all these cases, from defects in goods to rescission and compensation for use, in tens of thousands of proceedings. emissions scandal developed and applied to the new wave of electric car defects.
Do not sign any waiver or settlement agreement until your battery case has been reviewed.
The sooner your case is reviewed, the more options you have. Secure your claims while the deadlines are still open.
Rogert & Ulbrich – Your lawyers specializing in electric vehicle defect law
Rogert & Ulbrich represents consumers nationwide in vehicle defect law and has its own Automotive sector. The law firm of Dr. Marco Rogert and Tobias Ulbrich has taken on over 40,000 cases and filed more than 25,000 lawsuits in the emissions scandal. This experience in litigation is now benefiting buyers of electric cars.
We will assess the condition of your battery, legally classify the capacity loss, and quantify your claims. We will negotiate with the retailer and manufacturer out of court. If no satisfactory solution can be reached, we will enforce your rights in court, from contract cancellation and price reduction to compensation for damages.
Is your electric car battery losing capacity noticeably quickly? Get in touch and protect your rights.
