Controller displays “Low Battery” and generator will not crank or cranks very slowly, especially in cold weather.

Safety first: Place the generator in OFF mode and open the main AC breaker feeding the transfer switch. Wear eye protection and insulated gloves when working around batteries.

Steps:

• Inspect battery: Locate the 12 V starting battery in the generator enclosure. Check the date code; if older than 3–4 years, plan to replace it with an equivalent CCA-rated battery recommended by Eaton.
• Check terminals: Look for white/green corrosion on the battery posts and cable lugs. Clean with a baking soda/water solution and a wire brush. Rinse and dry thoroughly.
• Tighten connections: Ensure the positive and negative battery cables are tight on the posts and at the starter solenoid on the engine.
• Measure voltage: With a multimeter, measure DC voltage at the battery. A healthy, fully charged battery should read about 12.6–12.8 V with the generator off. If below 12.0 V, charge or replace the battery.
• Check battery charger: With utility power present and generator in OFF, measure DC voltage at the battery again. It should be around 13.2–13.6 V if the Eaton onboard battery charger is working. If not, inspect the charger fuse and AC feed; replace the charger module if it remains inactive.
• Clear alarm and test: After correcting issues, clear the alarm on the controller (per Eaton manual) and perform a manual test run to confirm normal cranking.