Battery knowledge · State estimation
Incremental capacity analysis
The inverse of differential voltage analysis: the derivative of charge with respect to voltage, plotted against voltage. Plateaus in the voltage curve become peaks whose height and position track aging, and it can be run on data a BMS already records.
- Abbreviation
- ICA
- Also called
- dQ/dV
- Relationship
- dQ/dV vs V
Example
Read capacity per voltage interval
If 0.10 Ah is transferred while voltage rises by 0.020 V, the local incremental capacity is about 5 Ah/V. Numerical differentiation can amplify noise, so a peak must be assessed with the measurement conditions.
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.