For a supplemental power generator, the starter battery needs periodic charging to ensure it remains ready for use. Here are some methods to charge it:

Many generators have a built-in trickle charger or system that charges the battery when the generator is running. If yours has this feature:

• Run the Generator Regularly: Start the generator periodically (e.g., once a month) and let it run for 10–20 minutes. This keeps the battery charged and ensures the engine stays in good working order.
• Check the Manual: Look for a setting or mode that indicates charging. Some generators automatically charge the battery when in standby mode.

If your generator doesn't have an automatic charging feature, or you want a more reliable way to maintain the charge:

• Choose a Smart Battery Charger: A smart or trickle charger with a 12V setting is ideal. It will maintain the charge without overcharging. Look for models with a “maintenance mode” or “float mode.”
• Connect the Charger:
  • Disconnect the battery cables from the generator to avoid any electrical issues.
  • Attach the charger’s clamps to the battery terminals (red to positive `+`, black to negative `-`).
  • Plug in the charger and let it run until the battery is fully charged. Smart chargers will automatically stop or switch to maintenance mode once charging is complete.

If your generator is stored outdoors or in a shed with sunlight, a small solar battery maintainer can help keep the battery charged over time without needing to be plugged in.

• Check the Battery Monthly: If your generator is not used often, check the battery voltage monthly. A fully charged 12V battery should read around 12.6–12.8 volts.
• Keep Terminals Clean: Corrosion can affect charging efficiency. Clean the battery terminals and apply a thin layer of petroleum jelly or battery terminal protector.
• Replace the Battery as Needed: Most generator batteries last 3–5 years. If the battery isn't holding a charge, it may be time to replace it.

Would you like recommendations for specific battery chargers, or have any questions about your particular setup?