The controller indicates E008 Battery Voltage Low; the generator fails to crank or cranks slowly.

Safety first: Isolate AC power to the battery charger before working on DC connections. Wear eye protection when working around batteries.

• Measure battery voltage: Use a multimeter across the battery terminals. For a 12 V system, expect around 12.6–13.6 V at rest/float. Anything below ~12.0 V indicates a low charge.
• Inspect terminals and cables: Clean corrosion from battery posts and lugs with a wire brush. Tighten all connections, including the engine ground strap and starter terminals.
• Check battery charger: Locate the Atlas Copco‑supplied battery charger module. Confirm it has AC supply and is outputting the correct DC voltage. Replace or repair if no output.
• Charge or replace batteries: If batteries are old or fail a load test, replace with the correct CCA rating. Ensure polarity is correct when reconnecting.
• Check for parasitic loads: With the generator off, measure DC current draw from the battery. Excessive draw may indicate a stuck relay or accessory left on.

After restoring proper battery voltage, clear the E008 alarm and perform a test start.