Wallbox charger’s app shows incorrect energy consumption or current values compared to an external meter.

Safety first: Measurement checks do not require opening the unit; keep mains power on unless internal work is needed.

• Compare over time: Measure energy with a reliable external meter over several full charging sessions to confirm consistent discrepancy.
• Check external meter settings: If using an external meter, verify CT ratios, phase assignments, and communication parameters.
• Firmware update: Ensure the Wallbox firmware is up to date, as some inaccuracies may be corrected in software.
• Recalibration (technician): If supported, a technician can recalibrate the internal meter using reference loads. If calibration cannot correct the error, replace the CTs or main board.

For billing‑grade accuracy, use a certified external meter even after internal repairs.