Generator displays E13 and refuses to start, especially in cold weather

Safety first: Ensure the generator is OFF and all AC breakers are open before working on the battery.

• Measure battery voltage: Use a multimeter at the battery posts. If below about 11.8V, the battery is significantly discharged.
• Charge or replace battery: Remove the battery and charge it with an external smart charger until fully charged. If it fails a load test or quickly discharges again, replace it with a battery that meets DuroMax specifications (CCA and size).
• Inspect charger: With utility power present, check the output of the built‑in battery charger at the battery terminals (typically 13.2–13.6V). If no charging voltage is present, check the charger fuse and wiring. Replace the charger module if faulty.
• Clean and tighten terminals: Remove corrosion from posts and clamps, apply dielectric grease, and tighten securely.
• Cold weather considerations: In very cold climates, consider a battery warmer and ensure the generator enclosure is not exposed to direct wind that can chill the battery.