We are gradually adding a number of electric vehicle and battery calculators to our pages. Here is a centralised list of pages with calculators built into them.
Do please send us ideas or even existing calculations that you make on the back of an envelope and would like to see as an online calculator.
Cell Energy Density
The calculations are quite simple as the energy content of the cell [Wh] = Vnom x Ahnom. This value is then just divided by the volume of the cell to calculate volumetric energy density or divided by the mass of the cell to calculated the gravimetric energy density.
There are some cautionary points though.
Creepage and Clearance Calculator
A simple creepage and clearance calculator, providing indicative minimum distances based on IEC 60664-1:2020 and ISO 21498:2021 table lookups with linear interpolation. It does not replace formal insulation coordination analysis by a qualified engineer. Always verify against the applicable standard for your specific application and jurisdiction.
Cylindrical Cell Electrode Estimation
Knowing the outer and inner diameter of the spiral along with it’s thickness we can calculate the length of the material to create it.
D is the inner diameter of the cylindrical can.
The inner diameter is that of the mandrel around which we wind the spiral.
Equivalent Lithium Content
The equivalent lithium content lithium content of a lithium ion cell is simply 0.3g x Ah capacity of the cell.
Note that if the cell is rated in mAh you just need to divide the number by 1000 to get Ah.
Pack Mass Estimation
Battery pack mass estimation is a key parameter required early in the conceptual design. There are a number of key reasons for estimating the mass, one of the main ones being the significant percentage it is of the overall mass of the complete system.
This calculator uses benchmark data to estimate the mass of everything other than the cells.
Pack Mass from Cell Density
The key relationship we have is between cell and pack gravimetric energy density.
This graph has been pulled together by scouring the internet for cell and battery data.
The ratio of cell density to pack density is 0.6235 and this is very close to the total cell to pack mass relationship of 1.6034
Pack Usable and Total Energy
The usable energy (kWh) of the pack is fundamentally determined by:
- Number of cells in series (S count)
- Number of cells in parallel (P count)
- Capacity of a single cell (Ah)
- Nominal voltage of a single cell (Vnom)
- Usable SoC window (%)
Energy (kWh) = S x P x Ah x Vnom x SoCusable / 1000
Note: this is an approximation as the nominal voltage is dependent on the usable window. Also, the variation in cell capacity will be needed to be understood to establish accurate pack capacity values in production. However, all of this takes time and hence please use this as a first approximation.
Pack Volume
Estimated as upper and lower limits based on data in the pack database.
Pre-Charge Resistor
When the battery pack contactors are closed onto a motor and inverter there will be an inrush of current into the inverter capacitor. This very high current is at a minimum likely to age the contactors, it could permanently damage the contactors.
Therefore, when we closed the contactors on the battery pack we do this in three steps:
- Close the main negative contactor
- Close a contactor with a resistor in series
- Close the main positive contactor
Closest Fit to a Battery Pack
Can we find a battery pack from the Battery Pack Database, using a limited dataset of 642 packs. Something that might get you an idea as to what you should be looking at?
EV Pack Charging Time
A pack charging time estimator built using the Electric Vehicle packs in the Battery Pack Database.
Estimates DC fast-charge time from pack size, chemistry, peak charging power, and a SoC window, then layers on a simplified thermal model — starting pack temperature, pack mass, and cooling power — since cold or heat-soaked packs are throttled well below their rated peak. Defaults (20°C start, room temperature) reproduce the pure SoC-taper estimate; change them to see cold-weather or thermally-limited charging.
Bidirectional Buck and Boost DC-DC
Circuit Diagram, Equations and Calculator for Calculating different aspects like Power, Current and Voltage average, Inductance, Switch On and off time etc in a Bidirectional Buck and Boost DC to DC converter. I will write an article separately explaining the workings of DC to DC converter.
Road Vehicle Power Demand
Let’s look at the road vehicle power demand for the simple steady state condition. We will look at the tractive effort and power required:
- Aerodynamic forces
- Rolling resistance
- Acceleration
- Gradients
- Hotel loads
Tesla CyberTruck – a look at the power and energy demands of this vehicle with the Road Vehicle Power Demand Calculator.
Electric Vehicle Range Calculator
Use this EV Range Calculator to predict your electric vehicle’s driving range based on real-world conditions. Select your vehicle (Tesla Model 3 or VW ID.4) or input custom specs to get a tailored estimate.
Drone Power and Energy Estimation
If we know the average power demand and the flight time we can estimate the energy required for the flight.
BESS Sizing
Nameplate energy is the installed gross capacity required at start of life. All outputs are first-order estimates for conceptual sizing — actual procurement should include system-specific losses, availability factors, and project contingency. C-rate above 1C: consider a power-optimised cell chemistry (e.g. LFP 2C-rated). C-rate below 0.25C: high-energy cells or longer-duration alternatives (e.g. flow battery) may be more economical.
