Battery knowledge · Units and electrical basics
Ohm’s law
Voltage across a resistance equals current times that resistance. Applied to a cell it predicts the voltage drop under load from the internal resistance, which is the first-order reason terminal voltage sags.
- Relationship
- V = I × R
Example
Explore the graph
Discharge current creates an ohmic drop below open-circuit voltage.
5 A through 20 mΩ gives 0.1 V ohmic drop.
V_terminal = OCV − I_discharge R
Illustrative model. Chosen OCV curve; no chemistry calibration, hysteresis or voltage cutoff.
Use in Lemonergy
Lemonergy Studio blocks
Passive cell balancer worked example
Hysteresis selects high cells and reports bleed current and resistor heat.
Blocks to use
- Passive cell balancer
Selects cells above the lowest cell voltage using separate turn-on and turn-off differences. Enabled channels report bleed current and resistor heat; the signal block itself does not impose the electrical current.
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.
- Review the block inputs, units and model limits.
- Open the Studio example and run its bundled model.
- Compare the output channels with the numerical checks; change one input and run again.
Example. Use the defaults below with Cell voltages = [3.95, 4, 3.96] V, Enable = 1 true / false. At 0 s, Bleed switches is [0, 1, 0] true / false. Additional checks are listed below.
Observe. Inspect the outputs and numerical checks on the block reference page.
Connect the request to a physical balancing interface to load a conserving network. The synthetic resistor is not a hardware rating. 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
Relate current and voltage
Conserving components solve constitutive relations and node balance.
Blocks to use
- Controlled voltage source
Supplies voltage
Inputs & settings
- voltageV
- Resistor
Relates current and voltage
Inputs & settings
- resistanceOhm
- Electrical reference
Sets zero potential
Inputs & settings
- Connect p to reference net
This overview identifies the components to use. Follow the example in Lemonergy for their connections and settings.
Example. A 1 V drop across 2 Ω implies 0.5 A.
Observe. Topology sets individual element voltages.
The RC example includes a capacitor: transient current varies and source voltage is not always resistor voltage.
Open the electrical circuit →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.
- The International System of Units (SI), 9th edition
Bureau International des Poids et Mesures · 2026
Topic background · Definitions of SI units and coherent derived units; 2026 revision.