Battery knowledge · Charging and discharging

Negative delta V

The small fall in a nickel cell’s voltage just after full charge, as overcharge heats it, used to end a fast charge. NiCd shows about 10–30 mV per cell, NiMH only around 5–10 mV and barely any below 0.5C, so NiMH chargers often stop at the voltage peak or plateau instead and back it up with dT/dt.

Abbreviation
−ΔV
Also called
-dV, -dV/dt, NDV, minus delta V, zero delta V, peak voltage detection

Example

Charging and discharging: an example situation

The same CC–CV law can operate overnight or during a short depot stop.

Read Negative delta V alongside Charge termination in this context. How a charger decides that a battery is full. Lithium-ion chargers end the constant-voltage stage when current falls to the taper current; nickel chargers watch for a small voltage drop or a fast temperature rise; lead–acid chargers drop to a float voltage. A safety timer and a temperature limit back up every method.

Use in Lemonergy

Separate regulation from availability.

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.

  1. Lithium-ion battery fast charging: A review

    Anna Tomaszewska et al. · eTransportation · 2019

    Topic background · CC-CV and alternative charging protocols, transport limitations, degradation and thermal implications; results depend on cell and test conditions. Software behavior is documented separately in Lemonergy block references.