Battery knowledge · State estimation
Differential voltage analysis
Plotting the derivative of voltage with respect to charge during a slow cycle. Its peaks mark electrode phase transitions, and how they shift between cycles separates lithium inventory loss from active-material loss without opening the cell.
- Abbreviation
- DVA
- Also called
- dV/dQ
- Relationship
- dV/dQ vs Q
Example
Explore the graph
Differentiate an authored monotonic voltage curve to see the information in DVA and ICA.
At the plateau center, dV/dq = 0.44 V per charge fraction; dq/dV = 2.273 charge fraction/V.
DVA = dV/dq; ICA = dq/dV = 1 / (dV/dq), q = Q/Q_nominal
Illustrative model. Normalized authored curve, not a measured cell fingerprint. Peak changes alone do not uniquely identify a degradation mechanism.
Use in Lemonergy
Distinguish internal states from noisy measurement estimates.
This is a reference concept. No executable Lemonergy block has been verified for this term.
References & further reading
Further reading on this topic
These sources provide broader context; they are not presented as citations for every statement in this entry.
- Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 3. State and parameter estimation
Gregory L. Plett · Journal of Power Sources · 2004
Topic background · Model-based battery state-of-charge and parameter estimation with extended Kalman filtering, including uncertainty and model dependence.
- Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 2. Modeling and identification
Gregory L. Plett · Journal of Power Sources · 2004
Topic background · Battery charge balance, open-circuit voltage, ohmic loss, polarization dynamics and model identification; parameters require cell-specific data.