What Size Battery is Needed For The Cummins Onan Generator?
Updated 01/15/2026 | Published 01/13/2026
Question:
what size cca battery do you need for a starting
asked by: Gerg
0
Expert Reply:
Hey Greg,
For the # CM32ZR Cummins Onan Generator you will generally need a 12V battery with 250-350 cold cranking amps. Usually a group 24 or 26 battery works just fine.
What are you going to be using this for?
expert reply by:
Nick S
0
Product Page this Question was Asked From
Onan Generator - Quiet Series 4000 EVAP Onboard RV Generator - 4,000 Watts - Gasoline
- Generators
- No Inverter
- Gas
- 3001 - 4000 Watts
- Onboard Generator
- 12V Output
- Carbureted
- Electric Start
- Cummins Onan
more information >
Featured Help Information
Instructions
Continue Researching
- Q&A: Replacement Onan QG-4000 Generator In A Jayco RedHawk 31XL
- Q&A: Replacement for Onan QG 4000 in 2022 Thor Coleman Motorhome
- Q&A: Is Cummins Onan 4000w Generator or Inverter model better for Forest River RV with Victron Inverter?
- Q&A: Replacement Lens For A 2018 Grand Design Solitude 373FB Ova; Flood Light
- Q&A: How Long Does It Take To Install Air Force One Supplemental Braking System
- Q&A: Recommended Replacement For A Dometic RM1350 RV Refrigerator
- Q&A: Atwood 87701 landing gear switch replacement
- Article: Using a Portable Generator on RV
- Article: The Ultimate RV Camping Checklist for Your First Year RVing
- Article: Trailer Drum Brakes vs. Disc Brakes: Making the Decision
- Article: 4 Steps to Choosing Your 5th Wheel Pin Box
- Article: Calculating Portable Generator Power Needs
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: How Does an RV Water Pump Work?
Gerg
1/14/2026
I’m looking at going lithium. Couldn’t find any info about amps required to start. So my thought is 400. Bms battery could start the generator ie 2 200 bms300 hr? Need to replace 6 volts batteries