Battery knowledge · Charging and discharging

Split-pack charging

Reconfiguring a pack with contactors so that its two halves charge in parallel at half the drive voltage. An 800 V vehicle such as the Tesla Cybertruck can then use 400 V fast chargers without a DC/DC booster; GM’s Hummer EV does the reverse, driving at 400 V and switching the halves into series to charge at 800 V.

Also called
bank charging, pack splitting, series–parallel switching

Example

Series voltage and parallel capacity

4S2P: 8 cells, 14.8 V, 10 Ah, 148 Wh.

Identical 3.7 V, 5 Ah cells; ideal equal current sharing and no losses.

Explore the graph

Count series and parallel connections separately.

Voltage along one series string
Voltage along one series stringSeries cells versus Voltage (V). 3.7 V per cell. Interpretation follows the graphs.0011.1322.2633.3944.412Series cellsVoltage (V)
3.7 V per cell
Capacity from parallel cells
Capacity from parallel cellsParallel cells versus Capacity (Ah). 5 Ah per cell. Interpretation follows the graphs.007.51.515322.54.5306Parallel cellsCapacity (Ah)
5 Ah per cell

4S2P: 8 cells, 14.8 V, 10 Ah, 148 Wh.

V_pack = Ns V_cell; Q_pack = Np Q_cell

Illustrative model. Identical 3.7 V, 5 Ah cells; ideal equal current sharing and no losses.

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.