Battery knowledge · Charging and discharging

IU, IUoU and IUI charging

The letter code, set out in DIN 41772, for a charger’s profile: I for a constant-current stage, U for constant voltage and W for current that falls as voltage rises. IUoU charges lead–acid at constant current, then at a raised voltage, then at a lower float voltage; IUI ends with a small constant current that finishes flooded traction cells and stirs their acid by gassing.

Also called
IUoU, IUI, IUIa, three-stage charging, W characteristic, DIN 41772

Example

Charging and discharging: an example situation

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

Read IU, IUoU and IUI charging alongside CC-CV charging in this context. The standard lithium-ion charge protocol: constant current until the cell reaches its upper cutoff voltage, then that voltage held constant while the current tapers. The charge ends when the current falls to a set fraction, often C/20.

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.