Charging System Voltage & Drop Checker

Turn multimeter readings into clear charging-system diagnosis steps.

Analyze Charging Health

Take loaded readings at about 1,500 to 2,000 RPM with headlights and blower on.

Reference Ranges

  • Battery resting: ~12.6V fully charged, 12.2V or lower indicates low state of charge.
  • Charging voltage: Usually 13.5V to 14.8V warm.
  • AC ripple: Below about 0.30V is typical on many vehicles.
  • Cable drop: Keep positive and ground path drop below about 0.20V each under load.