Charger reports undervoltage or low line voltage; charging stops or will not start; app shows low voltage warning.

Safety: Persistent undervoltage can overheat wiring and damage electronics. Do not ignore repeated warnings.

• Step 1 – Check other loads:
  • Turn off large loads (HVAC, ovens, dryers) and see if the charger operates normally.
  • If the error disappears, your service may be near capacity; consult an electrician.
• Step 2 – Measure voltage under load:
  • Have an electrician measure voltage at the panel and at the charger while charging.
  • If voltage drops significantly at the charger, upgrade the wire gauge or shorten the run.
• Step 3 – Inspect terminations:
  • With power OFF, check that all lugs at the breaker and charger input are tight and free of corrosion.
  • Retorque to manufacturer specifications.
• Step 4 – Internal fault:
  • If supply voltage is stable but the charger still reports undervoltage, the main control board sensing circuit may be faulty.
  • Replace the control board through an authorized service provider.