Battery second life for robots: cheaper replacement packs, with caveats
Battery second life for robots: cheaper replacement packs, with caveats
When a robot’s lithium-ion battery drops below 80% state of health (SoH), it is typically retired from service. But that pack may still hold 70% or more of its original capacity, enough for less demanding applications. In the EU, the new Batteries Regulation (Regulation (EU) 2023/1542) explicitly encourages reuse and repurposing, and a growing number of suppliers now offer second-life packs for industrial robots at 30–50% below the price of new ones. Yet the savings come with real risks: unknown usage history, uncertain degradation, and compliance obligations that vary by member state. This article explains what a buyer should verify before installing a second-life pack, and how the EU regulatory framework shapes the market.
The EU Batteries Regulation: a framework for reuse
The EU’s Batteries Regulation (Regulation (EU) 2023/1542) entered into force in 2023, replacing the 2006 Battery Directive. It is the first EU law to explicitly address second-life batteries, setting out requirements for repurposing, information sharing, and due diligence. Key provisions include:
- Definition of ‘repurposed battery’ – a battery that was designed for a different application and is then used for a new purpose. The regulation requires that repurposed batteries be clearly labelled and that the repurposer takes responsibility for their performance and safety.
- Battery passport – from February 2027, all industrial batteries with a capacity above 2 kWh (which includes most robot batteries) must have a digital passport. This passport will contain data on the battery’s composition, state of health, and usage history, making it easier to assess second-life suitability.
- Due diligence obligations – economic operators placing batteries on the EU market must address social and environmental risks in their supply chain, including for second-life packs.
- Waste hierarchy – the regulation prioritises prevention, preparation for reuse, and recycling, in that order. This gives legal backing to second-life markets.
The European Commission’s battery pages (see Sources) describe the regulation as a key step towards a circular economy for batteries, but they also note that implementation is left to national authorities. This means that specific requirements – such as registration, notification, or testing – can differ from one EU country to another.
What a buyer should verify before buying a second-life pack
Not all second-life packs are equal. The following checks are essential to avoid safety incidents, performance surprises, or regulatory non-compliance.
1. State of health (SoH) and capacity
SoH is the most critical parameter. It is usually expressed as a percentage of the original capacity, but the measurement method matters. Ask for the SoH at the time of sale, the date of measurement, and the testing standard used (e.g., IEC 62660 or a manufacturer-specific protocol). A pack with SoH below 70% may have a very short remaining life, especially under high load. Also request the internal resistance, as it affects power delivery and heat generation.
2. Usage history and provenance
Where did the pack come from? Was it used in a warehouse robot, a delivery drone, or an electric vehicle? High-vibration or high-temperature applications accelerate degradation. The battery passport, once mandatory, will provide this data, but until then, ask for service logs, charging cycles, and any repairs. Be wary of packs that have been stored for long periods at high state of charge – this can cause capacity loss even without use.
3. Warranty and liability
New packs typically come with a 2–5 year warranty. Second-life packs often have shorter or no warranty. The EU regulation does not mandate a specific warranty for repurposed batteries, but the seller must provide clear information about the performance and expected lifetime. Insist on a written warranty that covers capacity fade and sudden failure. Also clarify who is liable if the pack causes damage to the robot or property – the original manufacturer may not cover second-life packs.
4. Certification and compliance
In the EU, batteries must meet safety and performance requirements under the Batteries Regulation, including CE marking. For second-life packs, the repurposer must ensure that the pack still complies with the relevant standards. Ask for a Declaration of Conformity and any test reports. Also check if the pack is covered by the original manufacturer’s certification – often it is not, because the pack has been modified. In some countries, second-life batteries may require additional permits or registration as waste or as a product.
5. Compatibility with the robot’s BMS
The battery management system (BMS) in the robot is often proprietary. A second-life pack may have a different cell chemistry, voltage curve, or communication protocol. Ensure that the pack is compatible with the robot’s BMS, or that the BMS can be reprogrammed. Otherwise, the robot may not charge correctly, may underestimate range, or may shut down unexpectedly.
Comparison: new vs second-life battery pack
| Aspect | New battery pack | Second-life battery pack |
|---|---|---|
| Initial cost | High (100% of list price) | 30–50% lower (typical market range) |
| State of health (SoH) | 100% at delivery | 70–90% (varies by source) |
| Remaining useful life | Full rated cycle life (e.g., 1000–2000 cycles) | Reduced, often 300–800 cycles depending on SoH |
| Warranty | 2–5 years from manufacturer | Often 6–12 months or none; must be negotiated |
| Certification | CE marked, full compliance documentation | Must be re-certified by repurposer; may lack original CE |
| Compatibility | Guaranteed by OEM | May require BMS adaptation or testing |
| Environmental impact | Higher due to new material extraction | Lower, supports circular economy |
| Risk | Low | Higher – unknown history, potential hidden defects |
Practical advice for fleet operators
If you are considering second-life packs for your robot fleet, start with a pilot. Choose one robot and one pack from a reputable repurposer. Test it under your typical duty cycle for at least a month. Monitor temperature, capacity, and any error codes. Only then scale up.
Also, consider the total cost of ownership. A second-life pack may be cheaper upfront, but if it fails after six months and you have to replace it again, the cost per kilowatt-hour of useful energy may be higher than a new pack. Calculate the cost per cycle or per hour of operation.
Finally, keep documentation. The EU regulation requires that repurposed batteries be traceable. Save the battery passport data, test reports, and warranty documents. This will help you in case of disputes and for future compliance audits.
Conclusion
Second-life batteries for robots are a promising way to reduce costs and environmental impact, and the EU regulatory framework is supportive. But the market is still young, and quality varies. By verifying SoH, history, warranty, certification, and compatibility, you can mitigate the risks. As the battery passport becomes mandatory, transparency will improve, making second-life packs a more reliable option. Until then, proceed with caution and due diligence.
Sources
- EUR-Lex — Regulation (EU) 2023/1542 — https://eur-lex.europa.eu/eli/reg/2023/1542/oj (accessed 2026-08-11)
- European Commission — Batteries — https://environment.ec.europa.eu/ (accessed 2026-08-11)