Battery packs are at the core of today’s energy storage and e-mobility systems. Yet, the way cells are balanced inside these packs has remained stuck in a trade-off: passive methods are cheap but wasteful, while active solutions are efficient but costly and complex. The result is lost capacity, accelerated degradation, and shorter service life.
This whitepaper introduces ETA-Leveling, a firmware-based balancing strategy developed by PEM Motion together with Benning CMS Technology GmbH. By shaping charge currents intelligently, ETA-Leveling keeps cells synchronized from the start—without requiring additional hardware. The outcome is higher usable capacity, slower degradation, and lower costs across the battery lifecycle.
What You Will Learn
- The three main causes of imbalance (capacity spread, impedance mismatch, self-discharge) and why conventional balancing struggles to address them
- How ETA-Leveling prevents drift before it happens, rather than correcting it afterward
- Practical implementation paths, from simulation toolkits to firmware patches and turnkey BMS solutions
- Specific use cases that highlight cost savings, extended lifetimes, and second-life opportunities
Why ETA-Leveling Matters
Conventional balancing often wastes energy, bleeds the wrong cells, and accelerates the very degradation it seeks to prevent. ETA-Leveling changes this dynamic by:
- Using only the existing BMS sensors — no new hardware required
- Aligning all cells to reach full charge simultaneously, avoiding early cut-offs
- Recovering up to 52% of apparent capacity loss in aging packs
- Extending the usable life of batteries while reducing procurement and replacement costs
Frequently Asked Questions
Why is balancing such a big issue?
Even when cells come from the same batch, small differences in capacity, resistance, or self-discharge add up. Over time, this leads to reduced usable energy, faster aging, and potential safety concerns if not managed properly.
How is ETA-Leveling different from passive or active balancing?
Passive balancing burns energy as heat. Active balancing adds cost and hardware complexity. ETA-Leveling offers a third path: it runs purely in firmware, using existing measurements to keep cells aligned. This way, it delivers the efficiency of active systems without the overhead.
How much performance gain can I expect?
Field and simulation results show that ETA-Leveling can recover up to 52% of capacity typically considered lost, while doubling the effective cycle life compared to voltage-based balancing.
Does it require new hardware?
No. ETA-Leveling is a software-only upgrade. It integrates with the BMS you already have, making it simple and cost-effective to adopt.
In what applications does ETA-Leveling make the biggest impact?
- New packs: reduce procurement cost by enabling the use of unsorted cells without sacrificing performance
- In-field fleets: recover runtime and extend service life without replacing packs
- Second-life systems: stabilize mixed cells for energy storage, unlocking new revenue streams
How difficult is the implementation?
PEM Motion provides multiple entry points:
- Simulation modules for fast desktop validation
- Code integration into existing BMS firmware
- Turnkey BMS solutions with ETA-Leveling already included
Conclusion
Balancing is fundamental to battery performance, yet traditional methods force compromises that limit efficiency, reliability, and lifetime. ETA-Leveling removes these trade-offs. It is a simple, firmware-based solution that helps operators reclaim hidden capacity, charge faster and safer, and extend the useful life of their batteries—all without redesigning their hardware.
Download the whitepaper to explore how ETA-Leveling can redefine the way you manage your batteries and ensure that no kilowatt-hour goes to waste.