lemonergy· battery engineering courses

Battery knowledge · Modules, packs and battery management

Battery pack

The complete battery as installed: modules or cells, the BMS, contactors and fuses, busbars, cooling, sensors and an enclosure. Its energy is the sum of its cells’ energies; its mass and volume are a good deal more.

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

Lemonergy Studio blocks

Battery module worked example

Generated series/parallel cell hierarchy with individual SOC, RC and temperature states, KCL current sharing and optional thermal links. Causal pack-current boundary.

Blocks to use

  1. Battery module

    Builds an explicit series/parallel hierarchy with a separate SOC, two RC voltages and temperature for every cell. Subtree voltage/resistance reduction and Kirchhoff current sharing determine each cell current. Optional thermal links exchange equal and opposite heat. Per-cell overrides introduce controlled variation.

    Inputs & settings
    • Use the parameter values in the block reference.
    • Bundled example verified on the production release of 28 October 2026.

This overview identifies the components to use. Follow the example in Lemonergy for their connections and settings.

  1. Review the block inputs, units and model limits.
  2. Open the Studio example and run its bundled model.
  3. Compare the output channels with the numerical checks; change one input and run again.

Example. Use the defaults below with Signed pack current = 6 A, Cell ambient temperatures = [298.15, 298.15, 298.15, 298.15, 298.15, 298.15] K, External cell heat inputs = [0, 0, 0, 0, 0, 0] W. At 0 s, Pack terminal voltage is 10.92 V. Additional checks are listed below.

Observe. Inspect the outputs and numerical checks on the block reference page.

Bounded to 256 cells with the supported series/parallel construction. External pack current is imposed causally; no arbitrary geometry, conserving terminal adapter or topology reconfiguration. Each cell parameter set still needs characterization. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.

Open Studio example →

Lemonergy Studio blocks

Module assembly worked example

Generated series/parallel cell hierarchy with individual SOC, RC and temperature states, KCL current sharing and optional thermal links. Causal pack-current boundary.

Blocks to use

  1. Module assembly

    Builds an explicit series/parallel hierarchy with a separate SOC, two RC voltages and temperature for every cell. Subtree voltage/resistance reduction and Kirchhoff current sharing determine each cell current. Optional thermal links exchange equal and opposite heat. Per-cell overrides introduce controlled variation.

    Inputs & settings
    • Use the parameter values in the block reference.
    • Bundled example verified on the production release of 28 October 2026.

This overview identifies the components to use. Follow the example in Lemonergy for their connections and settings.

  1. Review the block inputs, units and model limits.
  2. Open the Studio example and run its bundled model.
  3. Compare the output channels with the numerical checks; change one input and run again.

Example. Use the defaults below with Signed pack current = 6 A, Cell ambient temperatures = 12 channels each 298.15 K, External cell heat inputs = 12 channels each 0 W. At 0 s, Pack terminal voltage is 21.84 V. Additional checks are listed below.

Observe. Inspect the outputs and numerical checks on the block reference page.

Bounded to 256 cells with the supported series/parallel construction. External pack current is imposed causally; no arbitrary geometry, conserving terminal adapter or topology reconfiguration. Each cell parameter set still needs characterization. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.

Open Studio example →

Lemonergy Studio blocks

Battery pack assembly worked example

Generated series/parallel cell hierarchy with individual SOC, RC and temperature states, KCL current sharing and optional thermal links. Causal pack-current boundary.

Blocks to use

  1. Battery pack assembly

    Builds an explicit series/parallel hierarchy with a separate SOC, two RC voltages and temperature for every cell. Subtree voltage/resistance reduction and Kirchhoff current sharing determine each cell current. Optional thermal links exchange equal and opposite heat. Per-cell overrides introduce controlled variation.

    Inputs & settings
    • Use the parameter values in the block reference.
    • Bundled example verified on the production release of 28 October 2026.

This overview identifies the components to use. Follow the example in Lemonergy for their connections and settings.

  1. Review the block inputs, units and model limits.
  2. Open the Studio example and run its bundled model.
  3. Compare the output channels with the numerical checks; change one input and run again.

Example. Use the defaults below with Signed pack current = 12 A, Cell ambient temperatures = 24 channels each 298.15 K, External cell heat inputs = 24 channels each 0 W. At 0 s, Pack terminal voltage is 21.84 V. Additional checks are listed below.

Observe. Inspect the outputs and numerical checks on the block reference page.

Bounded to 256 cells with the supported series/parallel construction. External pack current is imposed causally; no arbitrary geometry, conserving terminal adapter or topology reconfiguration. Each cell parameter set still needs characterization. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.

Open Studio example →

Learn it in Lesson 0 · Battery basics →

All connected Lemonergy block references

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. 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.

  2. Getting Started with the BQ76925

    Texas Instruments · 2019

    Topic background · A concrete BMS analog front-end example: cell voltage, current, temperature measurement and MCU integration.

Corrections or a better reference? Contact Lemonergy.

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