How to Fix / Troubleshooting

Safety first: Turn OFF the generator and disconnect battery negative before inspecting belts or wiring.

Check alternator belt: On belt-driven systems, inspect the belt for breakage or slippage. Replace and tension to Yamaha specifications.
Measure charging voltage: With the engine running, measure battery voltage. If it does not rise above resting voltage, the charging system is not working.
Inspect wiring: Check the charge lead from the engine alternator to the battery and ground connections for looseness or corrosion.
Test/replace alternator: If wiring is intact and there is no output, replace the engine charging alternator.
Verify external charger: Ensure the standby battery charger is powered and outputting correct voltage when the generator is off.

Generator runs but the battery repeatedly goes dead between exercise cycles.

Possible Causes