Caring for Low-Maintenance Generator Batteries

Honda generators equipped with electric start contain low-maintenance batteries manufactured by Yuasa. These batteries require very little maintenance, but they do require periodic charging. To get the longest service life from your battery, keep it fully charged at all times or recharge it each time you consume about a quarter of its capacity. Honda recommends that you keep the battery fully charged at all times to achieve maximum service life.

What if I seldom use my generator?

All batteries slowly lose strength when sitting idle; this is called self-discharge. They must be charged periodically, even when not being used, to prevent premature failure. If a battery is allowed to discharge past a certain point, it can never be recharged and must be replaced.

How do I know when my battery needs to be charged?

Measure the voltage of the battery with a digital voltmeter. If it measures 12.4 volts or less, you need to charge the battery. Check the voltage every three months to be sure the voltage remains above 12.4 volts.

Will the battery recharge while the generator is running?

Yes and no. Honda generators do charge their battery while the generator is running. Starting the engine discharges the battery somewhat, so the generator must run for some time just to replace the charge used to start the engine. Whether or not running the generator will keep the battery charged depends on:

  • How often you run the generator
  • How long you run the generator each time
  • The charge level of the battery when the generator started
  • The amount of charge required to start the engine
  • The ambient temperature
  • The age of the battery

Unless you plan to run the generator on a regular basis, plan to use an external charger to keep the battery charged.

How do I recharge the battery?

You can use a commercially available battery charger designed for 9 Ampere-hour (YTZ10S) or 11 Ampere-hour (YTZ14S) 12 volt batteries. Follow the charger manufacturer’s instructions and the instructions on the battery for connecting, using, and disconnecting the charger.

Honda recommends using an automatic charger/maintainer that you can leave connected to the battery to maintain its charge during storage. The Battery Tender® Plus (p/n 31670-HPE-000) and the Optimate 3+ (p/n 31670-BMS-004) automatic chargers are available from your Honda Power Equipment dealer. Both charge the battery to the proper level and then monitor the battery regularly to keep it fully charged.

Battery Tender Plus
Optimate 3+

Is any other maintenance required?

You should check the battery periodically to make sure the connections are tight. Clean any dirt or corrosion from the battery and associated wiring.

WARNING: Battery posts, terminals, and related accessories contain lead and lead compounds. Wash hands after handling.

Does my warranty cover the cost of replacing a dead battery?

Your battery’s warranty covers manufacturing defects; that is, quality problems from the factory. Allowing your battery to die through lack of use or inadequate attention during storage does not constitute a manufacturing defect. Take care of your battery to avoid an expensive, avoidable repair.