Electric Vehicles
EV Charging Loss Calculator
Measure charging loss and efficiency from wall and battery energy. Battery-energy estimates from displayed SOC can be imprecise.
Set the calculation inputs
Preserve measured precision during entry and round only the displayed answer.
The measurement being modeled
Measure charging loss and efficiency from wall and battery energy — the calculation follows energy or power through one defined electrical setup.
Battery-energy estimates from displayed SOC can be imprecise — that condition defines when charging energy loss is comparable with another result.
When you need to calculate the arithmetic relationship between EVSE current and a continuous-load breaker rating, avoid adding an improvised field here and open the EV Charger Breaker Size.
Input reference points
The Energy measured at wall entry represents utility-meter or charger energy for the session — before calculating, identify whether the reading is taken at the source, charger, battery, or accessory.
Energy stored in battery: Estimated pack-energy increase — a compatible entry should identify whether the reading is taken at the source, charger, battery, or accessory.
For Electricity price, use the quantity described as marginal energy price — in the vehicle record, identify whether the reading is taken at the source, charger, battery, or accessory.
The Highway Speed EV Range complements this result by calculating how to estimate EV highway range at another steady speed using an entered sensitivity exponent.
Operating conditions outside the formula
Control software, temperature, wiring loss, battery condition, and equipment limits can alter the measured electrical result — for electricity price, the page specifically expects marginal energy price.
After recording this output, use the Public Charging Idle Fee to estimate a public-charging idle fee after an entered grace period.
Turning the inputs into a result
In “charging loss = wall energy − battery energy added,” charging energy loss follows from the displayed relationship among energy measured at wall, energy stored in battery, and electricity price.
No term beyond energy measured at wall, energy stored in battery, and electricity price is introduced in “charging loss = wall energy − battery energy added.”
Following one calculation through
For a numerical demonstration, retain Energy measured at wall = 48.5 kWh, Energy stored in battery = 43.2 kWh, and Electricity price = $0.18/kWh.
Substitution into the equation gives Charging energy loss = 5.30 kWh, Charging efficiency = 89.1%, and Cost of charging losses = $0.95.
Using the supporting measurement
Charging energy loss answers “Measure charging loss and efficiency from wall and battery energy.” The additional displays, Charging efficiency and Cost of charging losses, are a different view of the same entered measurements.
Separate vehicle preconditioning or cabin consumption when possible — when that condition changes, compare separate calculator runs instead of blending the inputs.
Because battery-energy estimates from displayed SOC can be imprecise, a disagreement between charging energy loss and an outside reference should trigger a review of energy measured at wall and electricity price.
Keep this result separate from the task to estimate EV driving range from usable battery energy and expected consumption, which is available in the EV Battery Range.
Before using this result
What measurement source fits Energy measured at wall when it represents utility-meter or charger energy for the session?
Because energy measured at wall represents utility-meter or charger energy for the session, use a source tied to the exact vehicle, component, and operating period described by the other fields.
How does the warning “Battery-energy estimates from displayed SOC can be imprecise” affect Charging energy loss?
The condition “Battery-energy estimates from displayed SOC can be imprecise” is not corrected automatically by the numeric inputs, so create a separate ev charging loss case when it changes.