Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns.
Charger Warning: Error code 2770
Environment
This error applies to error code 2770, BATTERY PROBLEM, for air-cooled home standby generators.
Note: The term "error code" is used interchangeably with 'alarm code,' 'fault code,' 'fault alarm' and similar terminology. Error code applies to all such terminology.
Overview
- Error Code: 2770
- LED Indicator: Yellow
- Mobile Link Message: The battery is not charging properly. Please replace the battery or contact a dealer.
- Fault: CHARGER WARNING
- Issue: Battery is not charging.
- Potential Causes: Blown T1 fuse, charging circuit issue, or battery requires replacement.
What can I do?
- Your options are limited beyond performing basic troubleshooting checks and verifying that everything appears normal.
- You can attempt to clear the alarm and manually restart the unit: How Do I Clear an Error or Alarm Code On My Home Standby Generator?
- Sometimes, clearing the alarm and attempting to restart the unit is all that is needed, as the alarm may be a one-time occurrence that does not indicate a persistent issue.
DANGER: Generac support does NOT recommend end users attempt to modify or service internal generator wiring. Generac independent authorized service dealers are trained to service Generac generators and can be contacted using the dealer lookup tool on Generac.com: https://www.generac.com/dealer-locator


When should you contact a Generac Independent Authorized Service Dealer (IASD)?
If issues persist after performing the checks and attempting to restart, contacting a Generac IASD for diagnosis is strongly recommended.
General troubleshooting
What it indicates: This warning signals when the battery voltage is below 12.5 volts at the end of an 18-hour charge cycle, indicating the battery isn’t charging properly.
Checks to perform
- Check battery health in Mobile Link or at the generator's controller.
- Check that charging connections at the battery terminals are secure.
- Check for corrosion on the battery connections or terminals.
- Check the T1 fuse: What is the T1 fuse in my transfer switch?
DANGER: Generac does NOT recommend untrained end users attempt to service fuses in transfer switches. This fuse is always live with 120v, even when the generator is not running. To locate a local authorized service dealer, see the How Can I Find a Generac Service Dealer in My Area? article.
Troubleshooting next steps
Contact a Generac Independent Authorized Service Dealer (IASD) to professionally diagnose and resolve the issue.