Safety first: Turn OFF the generator and disconnect AC supply to the battery charger. Use PPE when working around batteries.

Measure DC voltage: With a multimeter, measure battery voltage with charger disconnected and then with charger connected. For 12 V systems, float voltage should be around 13.5–13.8 V; for 24 V, around 27–27.6 V.
Check charger settings: On the Kohler-SDMO charger, verify the correct nominal voltage (12/24 V) and charging mode are selected. Correct any misconfiguration.
Inspect charger: If output voltage is significantly above spec, replace the charger module. Check for internal fuses or adjustment pots only if authorized by manufacturer instructions.
Inspect wiring: Ensure battery negative and positive cables are tight and not intermittently disconnecting, which can cause spikes.
Reset alarm: After correcting the issue, clear AL07 and monitor battery voltage over several hours.

Prolonged overvoltage can damage the battery and controller; replace any swollen or leaking batteries.

Controller shows AL07 / Battery Voltage High while generator is running or on standby

Possible Causes