The Batemo Cell Model of the lithium-ion battery cell Ampace 21700A is a high-precision, physical battery model with global validity. As a digital twin it seamlessly integrates into your research, development and battery analytics by basing your decisions on simulations.
| Cell Origin | purchased on free market |
| Cell Format | 21700 |
| Dimensions | 21.1 x 70.2 mm |
| Weight | 68.2 g |
| Capacity definition
The nominal capacity originates from the manufacturer’s data sheet, if available. When the data sheet is unavailable, the nominal capacity is estimated. Batemo measured the C/10 capacity by discharging the cell at an ambient temperature of 25°C from 100% with a constant current of 0.40A (0.1C) until reaching the voltage of 2.5V. The thermal boundary condition is free convection. |
nominal 4.00 Ah C/10 4.15 Ah |
| Current definition
All quantities are measurement results from the Batemo battery laboratory. The continuous current is the highest current that completely discharges the cell without overheating it. Therefore, the cell is discharged from 100% state of charge (SOC) at an ambient temperature of 25°C with a constant current until a residual state of charge of 10% and either the lower voltage limit of 2.5V or 90% of the maximum surface temperature (72°C) is reached. The peak current is the current that the cell can supply for 5 minutes. The cell is therefore discharged from 100% SOC at an ambient temperature of 25°C with a constant current until it reaches either the lower voltage limit of 2.5V or the maximum surface temperature of 80°C after 5 minutes. For cells that reach the maximum surface temperature, the measured current is taken directly as the peak current. For cells that do not reach the maximum surface temperature after 5 minutes because they reach the lower voltage limit first, the measured current is multiplied by a correction factor that estimates the current that would have heated the cell to the maximum surface temperature within 5 minutes. The thermal boundary condition is free convection. These operating conditions may be outside the cell manufacturer’s specification. |
continuous 36.9 A peak 46.1 A |
| Energy definition
Batemo measured the C/10 energy by discharging the cell at an ambient temperature of 25°C from 100% with a constant current of 0.40A (0.1C) until reaching the voltage of 2.5V. The thermal boundary condition is free convection. |
C/10 15.5 Wh |
| Power definition
All quantities are measurement results from the Batemo battery laboratory. The continuous power is the highest power that completely discharges the cell without overheating it. Therefore, the cell is discharged from 100% state of charge (SOC) at an ambient temperature of 25°C with a constant current until a residual state of charge of 10% and either the lower voltage limit of 2.5V or 90% of the maximum surface temperature ( 72°C) is reached. The peak power is the power the cell can supply for 5 minutes. The cell is therefore discharged from 100% SOC at an ambient temperature of 25°C with a constant current until it reaches either the lower voltage limit of 2.5V or the maximum surface temperature of 80°C after 5 minutes. For cells that reach the maximum temperature limit, the measured power is directly taken as peak power. For cells that do not reach the maximum surface temperature after 5 minutes because they reach the lower voltage limit first, the measured power is multiplied by a correction factor that estimates the power that would have heated the cell to the maximum surface temperature within 5 minutes. The thermal boundary condition is free convection. These operating conditions may be outside the cell manufacturer’s specification. |
continuous 128 W peak 161 W |
| Energy Density definition
The energy densities result from the C/10 energy, the cell weight and the cell volume. |
gravimetric 227 Wh/kg volumetric 630 Wh/l |
| Power Density definition
The power densities result from the peak power, the cell weight and the cell volume. |
gravimetric 2.36 kW/kg volumetric 6.55 kW/l |
Ampace 21700A Model
The Batemo Cell Model of the lithium-ion battery cell Ampace 21700A is a high-precision, physical cell model with global validity. As a digital twin it seamlessly integrates into your research, development and battery analytics by basing your decisions on simulations. See the details to learn more about the features and capabilities of the Batemo Cell Model.
| Batemo Cell Model Version | 1.312 |
| Release Date | December 31, 2023 |
Batemo demonstrates the accuracy and validity of the Batemo Cell Model by comparing battery simulation and measurement data in the range given below. Validation is extensive, experimental characterization covers the total operational area of the cell: At low and high temperatures, up to the maximal current and in the whole state of charge range.
| State of Charge Range | 0 … 100% |
| Current Range definition The current range are the electrical current limits as used in the Batemo battery laboratory. Please see the Ampace 21700A data sheet for the precise definition of the current safe area of operation of the cell. |
-120 A discharge … 16 A charge (-30.0C … 4.0C) |
| Voltage Range definition The voltage range are the electrical voltage limits as used in the Batemo battery laboratory. Please see the Ampace 21700A data sheet for the precise definition of the voltage safe area of operation of the cell. |
2.5 … 4.2 V |
| Temperature Range definition The temperature range are the thermal limits as used in the Batemo battery laboratory. Please see the Ampace 21700A data sheet for the precise definition of the temperature safe area of operation of the cell. |
-20 … 80 °C |
Moreover, the validation of the Batemo Cell Model is fully transparent. The Batemo Cell Data contains the raw measurement and simulation data. For all experiments the voltage, temperature, power and energy accuracies are calculated. This allows straight-forward evaluation and analysis of the Batemo Cell Model validity. The graphs show a selection of characteristic data of the cell Ampace 21700A to evaluate the cell performance.
Discharge Characteristics
- Discharge Characteristics: The electrical and thermal discharge behavior is strongly nonlinear.
- Pulse Characteristics: The shape of different current pulses changes strongly.
- Energy Characteristics: The graph visualizes how much energy the cell can deliver when operated at different powers.
- Power Characteristics: The more power the cell supplies, the shorter it can deliver the power.
- Thermal Characteristics: The greater the thermal losses, the more the cell heats up, resulting in higher depleted power.
Pulse Characteristics
show experiment definitions
The cell is discharged from 100% SOC with different constant currents at different ambient temperatures. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or the surface temperature of 80°C.
The cell is discharged from 100% SOC with current pulses followed by no-load phases at different ambient temperatures. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or the surface temperature of 80°C. The graph shows a zoomed view of the measurement to visualize one of the pulses.
The cell is discharged from 100% SOC with different constant currents at 25°C. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or the surface temperature of 80°C. The graph shows the derived exchanged energy and average power of the experiment.
The cell is discharged from 100% SOC with different constant currents at 25°C. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or the surface temperature of 80°C. The graph shows the derived experiment duration and average power of the experiment.
The cell is discharged from 100% SOC with different constant currents at 25°C. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or the surface temperature of 80°C. The graph shows the cell surface temperature at the end and the derived average power of the experiment.
Energy Characteristics
How much energy can it deliver?
Power Characteristics
How long can it deliver the power?
Thermal Characteristics
How hot does it get?
The mean accuracies give an overview of the Batemo Cell Model accuracy. Therefore, the root mean square of the difference between the measurement and simulation result is derived for the voltage, the temperature, the energy and the power. Relative numbers relate the accuracy to the respective absolute value.
| Mean Voltage Accuracy | 0.025 V | 0.8 % |
| Mean Temperature Accuracy | 0.7 K | 0.7 % |
| Mean Power Accuracy | 0.37 W | 0.8 % |
| Mean Energy Accuracy | 0.120 Wh | 1.3 % |
The Batemo Cell Model precisely describes all aspects of the cell. It is the perfect tool for battery system development.
Ampace 21700A Data
Batemo offers an extensive, experimental characterization of the lithium-ion battery cell Ampace 21700A. The data contains measurement results in the total operational area of the cell. The descriptions and graphs below explain and show the available measurements. The Batemo Cell Viewer allows easy and fast analysis, evaluation and comparison of the data. See the details to learn more.
Constant Currents
The cell is discharged from 100% SOC or charged from 0% SOC with different constant currents at different ambient temperatures. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or 4.2V or the surface temperature of 80°C. The graph shows for which ambient temperatures and charging and discharging constant currents measurements are available.
Pulse Currents
The cell is discharged from 100% SOC or charged from 0% SOC with current pulses followed by no-load phases at different ambient temperatures. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or 4.2V or the surface temperature of 80°C. The graph shows for which ambient temperatures and pulse currents measurements are available.
Power Profiles
The cell delivers a typical power profile from 100% SOC at different ambient temperatures. The thermal boundary condition is free convection. The measurement stops when reaching either the voltage of 2.5V or the surface temperature of 80°C. The table summarizes for which ambient temperatures the profile is available.
| Ambient Temperature | Available |
|---|---|
| -20 °C |  |
| 0 °C | |
| 25 °C | |
| 40 °C | |
