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. 

Home standby generator batteries

Home standby generators do not come with a battery, and it must be purchased separately. This article provides a reference for generator owners who need to purchase or replace the battery on an air-cooled home standby generator.
 

Environment

This article applies to the Generac air-cooled home standby generators pictured below. For portable generators, see: Where Do I Get a Replacement Battery for My Portable Generator?

 

Where can I find which battery my generator needs?

For specific battery size information, reference the generator's spec sheet or check the Battery Type Section of your generator's product overview on the product lookup page tool. To find information on your specific model, enter the product serial number or model number.

Note: many home standby generator models share the same battery specifications, but owners should always consult the official user manual to verify the appropriate battery type.

Example of a generator's battery type shown on a product page on Generac.com:

Battery compatibility chart

Generator type	Group 26R 540 CCA	35 AGM 650 CCA	AGM PowerSports Battery, Group Size 30L, 400 CCA	Group U1, 12 volts and 300 CCA minimum	Supports charging AGM batteries
Older models	✓
Guardian series	✓	✓ (Must have Evolution controller)			See owners manual
Next Generation Air-Cooled Generator			✓ (part A0010137452 or A0010137451)		✓
7.5 kW PowerPact				✓
Liquid-cooled	*See spec sheets and owner manuals	*See spec sheets and owner manuals	*See spec sheets and owner manuals	*See spec sheets and owner manuals	*See spec sheets and owner manuals

Note: Next Generation air-cooled generators use an AGM PowerSports Battery, Group Size 30L, 400 CCA. Battery part numbers are A0010137452 and A0010137451. Battery tray kit is G00735230.

Note: Liquid-cooled generator battery requirements vary. Generator owners should always consult their product's spec sheets and owner manuals to confirm battery compatibility. See How Do I Find a Copy of My Home Standby Generator Owner's Manual, Spec Sheets, or Installation Manual? for more information.

Why doesn't this article provide battery part numbers for all generator models?

There are a variety of battery choices and there is often no "one size fits all" option. When selecting a battery, consider that:

• Battery choice depends on factors like environment (temperature) and generator type.
• The most important factor is group and U designation, as this indicates where the terminals are and the battery dimensions. The battery must fit and orientate correctly within the unit.

Where to purchase

• Air-cooled standby generators can typically be purchased from an auto parts store.
• A local authorized dealer can also assist in obtaining a replacement battery: Where Do I Get a Replacement Battery for My Generac Generator?
• Batteries can also be purchased from Generac's OrderTree site. Parts specific to your generator can be found by entering your Generator's model number.

 

Battery replacement

See How Do I Inspect the Battery On My Home Standby Generator? and How do I replace the battery on my home standby generator?

Battery disposal

Dispose of batteries according to state and local regulations. It is essential to follow all guidelines to prevent environmental harm. 

Battery FAQ

What are cold cranking amps (or CCA)?

CCA measures a battery’s ability to start an engine in cold temperatures. The higher the CCA, the better the battery will perform in colder climates.

Is the red terminal (cable) always positive?

This is not written in stone; however, red cables and terminals typically will be positive.

 
In what order do you disconnect and connect the battery cables?

When disconnecting, start with the negative cable first. When reconnecting, connect the positive first, then the negative.

See also

• How Do I Inspect the Battery On My Home Standby Generator?
• How Is My Home Standby Generator Battery Charged and What Voltage Should It Read?
• How to view you home standby generator's battery voltage