Perkins generator controller displays E012 and indicates battery voltage low

Safety: Wear eye protection when working around batteries. Avoid sparks and open flames.

• Measure battery voltage: With the engine stopped, measure across the battery terminals. Compare to nominal values (12 V or 24 V system). If low, attempt to charge with an external charger.
• Inspect charger: Check the panel‑mounted battery charger (often 230/120 V AC input). Verify AC supply is present and indicator LEDs show normal operation. Measure charger output voltage at the battery.
• Clean and tighten terminals: Remove corrosion from posts and lugs using a wire brush. Refit and tighten securely. Apply a light coat of dielectric grease.
• Load test batteries: Use a battery load tester to assess capacity. Replace batteries that cannot maintain voltage under load with the correct CCA rating for the Perkins engine.
• Controller settings: Confirm the low‑voltage alarm threshold in the controller matches the system design. Adjust if incorrectly set.