Battery voltage is very low fault (2751)

The “Battery Voltage is Very Low” fault appears when the generator’s battery charge drops far below the required level for proper operation.

Environment

This article applies to:

• Next Generation Series air-cooled home standby generators with the Power Zone 200 control panel.

Overview

Error code: 2751

LED Indicator: Red

Alarm: Very Low Battery

Mobile Link Message: “Battery voltage is very low.”

• For details about the maintenance reminder or warning, open Mobile Link for Generators on a mobile device or computer.

Why is this message shown?

• The battery charge level has fallen below the acceptable level. Please inspect or replace battery. If necessary, please contact a dealer.
  • Battery voltage is below 9 VDC for ≥60 seconds.
• More likely on new installations due to installation of a partially discharged (“stale”) battery before the onboard charger completes its initial cycle, or if control/battery connections are not fully landed.
  • New installations: Check connections and allow the onboard charger at least 18 hours to complete its initial charge cycle then clear the alarm. See below for more detail. 

Note: the alarm may clear automatically once charging is complete.

Resolution

1. Check connections.

• • Have the installer verify that control wires and battery cables are correctly landed, tight, and free of corrosion. For more information, see: What is the layout of the control wires and what do they do?

IMPORTANT: During installation, if related charger warnings appear, verify the battery charging circuit neutral and required conductors are landed per the installation manual. Incorrect or missing wiring can prevent charging.

2.Allow charging on new installs.

• • Permit at least 18 hours for a full charge cycle.

3. Clear the alarm.

• • Hold OFF for ≥3 seconds, then press AUTO. See How Do I Clear an Error or Alarm Code On My Home Standby Generator?

Note: the alarm may clear automatically once charging is complete.

4. If the alarm persists.

• • Replace the battery per the model’s specifications and recheck or contact a Generac Independent Authorized Service Dealer for assistance.

When to contact a dealer

• If the battery fails a load test or the "Battery voltage is very low" fault returns after completing the steps above, contact an IASD via the dealer locator. 
  • For more information, see: What Is a Generac Independent Authorized Service Dealer (IASD)? 

Related resources

• Troubleshooting home standby battery alarms and error codes
• What does low battery (2750) mean?
• Selecting and replacing a battery for a home standby generator
• New install shows charger warning or charger missing AC
• What Do the Green, Yellow, Blue and Red Status Indicator Lights Mean on Home Standby Generators?

Need manuals?

Find the owner’s manual for the exact model on the product lookup page.