Controller indicates CHARGER FAIL or BATTERY CHARGER ERROR; battery voltage slowly drops over days.

Safety first: Turn OFF AC power feeding the charger at the service panel. Then turn OFF the generator and disconnect the battery negative.

Steps:

• Verify AC input: Check the breaker or fuse feeding the Gillette battery charger. Restore power if tripped.
• Inspect charger: Open the control panel and locate the charger. Check for indicator LEDs showing a fault. Inspect for a burned smell or components.
• Measure DC output: With AC restored and the battery connected, measure charger output at the battery. If zero or very low, check any inline DC fuse. Replace the fuse or charger as needed.
• Secure connections: Tighten DC output terminals at both the charger and the battery.