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. 

Note: Troubleshooting in this article requires inspecting wiring, which should only be performed by a Generac authorized service dealer or licensed electrician. See the How Can I Find a Generac Service Dealer in My Area? article for more information.

Issue

A newly installed battery will not maintain a charge. 

Environment

 

If you have a Next Generation Series generator, see here.

If you have a Guardian Series generator, see here.

 

Note: To resolve a battery charging issue with your portable generator, see here: Portable generator battery charging guidelines

 

Next Generation Series generators

The battery charger is integrated into the Power Zone 200 control panel. It operates as a smart charger, verifying output charging levels are safe and continuously optimized to promote maximum battery life.

 

If the battery is not charging, a yellow light may appear on the LED display on the side of the generator, along with one these warnings, which may appear in Mobile Link:

• CHARGER MISSING AC: Code 2780
• CHARGER WARNING: Code 2770
• BATTERY PROBLEM: Code 2760
• LOW BATTERY: Code 2750

To resolve, we recommend:

1. Reviewing the article Understanding the home standby generator's battery charging system

2. Inspecting the battery: How Do I Inspect the Battery On My Home Standby Generator?
3. If necessary, replace the battery: How do I replace the battery on my home standby generator?
4. Have a Generac authorized service dealer verify the T1 and 00/T2 control wires were properly connected in the generator and the automatic transfer switch. See What is the layout of the control wires and what do they do? for more information.
5. Have a Generac authorized service dealer  verify the T1 fuse in the transfer switch is in place and not blown. See Where Is the T1 Fuse on My Home Standby Control Panel and What Does It Do? for more information.

Guardian Series generators

Single-phase Guardian Series generators with the Nexus or Evolution control panel must have 120VAC input to the T1 terminal on the generator. This circuit powers the controller's internal battery charger. If there is an issue with the T1 circuit, then the battery will not charge.

 

If the battery is not charging, a yellow light may appear on the LED display on the side of the generator, along with one these warnings, which may appear in Mobile Link or on the generator's control panel display:

• CHARGER MISSING AC: Code 2780
• CHARGER WARNING: Code 2770
• BATTERY PROBLEM: Code 2760
• LOW BATTERY: Code 2750

To resolve, we recommend:

1. Reviewing the article How Is My Home Standby Generator Battery Charged and What Voltage Should It Read?

2. Inspecting the battery: How Do I Inspect the Battery On My Home Standby Generator?
3. If necessary, replace the battery: How do I replace the battery on my home standby generator?
4. Have a Generac authorized service dealer verify the T1 and NEU/00 control wires were properly connected in the generator and the automatic transfer switch. See What is the layout of the control wires and what do they do? for more information.
5. Have a Generac authorized service dealer  verify the T1 fuse in the transfer switch is in place and not blown. See Where Is the T1 Fuse on My Home Standby Control Panel and What Does It Do? for more information.

Note: Newer Guardian series generators have a NEU/00 wire which must be connected in order for the battery to charge. Contact your installer to verify this wire was connected. See: What is the layout of the control wires and what do they do?

 

See also

 

• What Battery Do I Need for My Home Standby Generator?
• What Does the "Inspect Battery" Message Mean on My Generator?
• How Often Do I Need to Replace the Battery in My Generator?