OWNER ANSWER
Why charging kWh does not match your BYD’s battery percentage
The kWh on a charging receipt includes energy used during charging, while the battery percentage shows an estimate of stored charge. Conversion losses, battery temperature control and cabin systems can make the receipt higher than the energy added to the battery.
- Use the session’s start and finish percentages from the car.
- Use the correct usable battery capacity if it is known.
- Estimate stored energy as usable capacity multiplied by the percentage-point gain.
- Compare that estimate with the charger’s delivered kWh, allowing for rounding and different measurement points.
- For home charging, separate the charger reading from a whole-house meter that also includes other appliances.
Worked example — not a BYD specification
For a hypothetical 60 kWh usable battery, going from 20% to 70% adds roughly 30 kWh. A 34 kWh receipt is 4 kWh higher; 30 ÷ 34 is about 88%. This illustrates the calculation, not a fixed loss allowance or battery-health test.
kW and kWh
kW is the rate; kWh is the energy delivered over time. AC charging converts power in the car; DC follows a different path but still uses energy for losses and supporting systems. Gross battery capacity and usable energy are different figures.
If that did not work
For a billing discrepancy, ask the operator or supplier to check the session meter and receipt. For a repeated unusual difference with charging warnings, give BYD comparable session details rather than interpreting the calculation as a battery diagnosis.
Related links
Source: Osprey Charging · Octopus Electroverse. Checked 22 October 2026.