Battery knowledge · Testing methods
Cycle-life test
Repeating a defined charge and discharge cycle at fixed temperature until capacity reaches the end-of-life criterion, with a reference performance test every few hundred cycles. Conditions — rate, depth of discharge, voltage window, temperature — decide the result, so they are always quoted with it. [1]
- Also called
- cycling test, endurance test
Example
Capacity loss and resistance growth
At the illustrated endpoint: 80% initial capacity and 140% initial resistance.
Chosen qualitative trends. The exposure axis is not predicted cycles or years.
Explore the graph
Energy capability and power capability can degrade differently.
At the illustrated endpoint: 80% initial capacity and 140% initial resistance.
Capacity ratio = Q_now/Q_initial; resistance ratio = R_now/R_initial
Illustrative model. Chosen qualitative trends. The exposure axis is not predicted cycles or years.
Use in Lemonergy
Design protocol or analysis tool
Repeat charge/discharge
Cycle aging block repeats charge, discharge and rest.
Equation or tool to use
- Repeat
Repeats blocks
Inputs & settings
- count
- Discharge
Removes charge
Inputs & settings
- mode: cc
- a / s
- Rest
Sets zero current
Inputs & settings
- s
- Charge
Adds charge
Inputs & settings
- mode: cc
- a / s
This overview identifies the components to use. Follow the example in Lemonergy for their connections and settings.
- Open Cycle aging block.
- Review currents and rests; compare throughput.
Example. Twenty 50%-depth discharges give ten discharge-equivalent full cycles at fixed nominal capacity.
Observe. Cycle count differs from throughput.
Scheduling cycles does not supply calibrated degradation or physical lifetime evidence.
Open Design → Protocol bench →References & further reading
Technical references
- Battery Test Manual For Electric Vehicles, Revision 3
Jon P. Christopherson · Idaho National Laboratory · 2015
Technical reference · Performance characterization, pulse resistance/power, life testing and reference performance tests; historical 2015 edition.