Finding the Best Battery for Your Generac 22kW Generator + Troubleshooting

Regarding finding the best battery for Generac 22kW generator, I can confidently say that my journey has been both fascinating and challenging. 

I’ve been using this generator since September 2015, and once I had to replace the original battery that came with it, the real adventure began. Little did I know that the market would be flooded with options that didn’t quite fit the bill for my Generac 22 KW. But let me tell you, persistence pays off! After trying out multiple batteries and putting in some good old trial and error.

I finally stumbled upon the perfect battery solution for my trusty generator. And in this article, I’m thrilled to share all the details so you, too, can have the smoothest experience with your Generac 22kW generator. Let’s dive right in!

Our Pick

Genuine Battery for Generac

Polaris SEALED RG26P


Odyssey Battery ODP-AGM35

Odyssey Battery ODP-AGM35

DieHard Silver Battery: 26R Group

DieHard Silver Battery

EverStart Acid Battery, 26R

EverStart Lead Acid Battery

Duracell Automotive Battery, Group Size 26R

Duracell Automotive Battery

Most Recummended

Genuine Best Battery for Generac 22kw generator [By Generac]

8.5Out of 10
  • Made by Generac
  • 525 Cold Cranking Amps
  • 12 Volts DC
  • Model 26R Wet Cell Battery

The best-wet cell battery for the Generac 22kW Generator is the genuine battery designed by Generac specifically for this model. It outperforms the competition in terms of performance and dependability.

This battery ensures that your generator will start when you need it most, providing peace of mind and security during power outages. Generac has used its expertise to create a battery that perfectly complements the 22kW generator, ensuring seamless integration and optimized performance. 

If you want your generator to run smoothly and efficiently, this original wet-cell battery is the best option.


  • Easy to fit in Generac 22kW generator
  • Perfect replacement for original


  • The price is higher than others of this size
Best Alternatice

Polaris SEALED RG26P-WS AGM BATTERY 600+ CCA [Powerful than Geniun]

8.5Out of 10
  • 600+ Cold Cranking Amps
  • 12 Volts DC
  • Model 26R Wet Cell Battery
  • Sealed Maintenance free

If you’re searching for a substitute for an authentic battery, the Polaris SEALED RG26P Battery is an excellent option for the Generac 22kW generator.

This battery is ideal for your generator due to its high power, dependability, and durability. Moreover, it is completely sealed, preventing any concerns related to spills or leaks.

This battery boasts an impressive 600+ Cold Cranking Amps (CCA’s), ensuring reliable starting power even in cold weather. Additionally, it requires no maintenance, so you need not worry about leaks or corrosion. The best part? It’s completely hassle-free.

This 12-volt battery weighs 32 pounds and is specifically designed to fit your generator, ensuring its smooth operation.

The battery dimensions are: 6.89″D x 8.25″ W x 7.48″H


  • Affordable price
  • High amp which will help an easy start


  • Some users report it doesn’t fit in the generator.
  • Always check the dimensions of your generator’s battery place.
Editor’s Choice

Odyssey Battery ODP-AGM35 Best High Power

8.5Out of 10
  • Made by Odyssey Battery
  • 675 Cold Cranking Amps
  • 12 Volts DC
  • Model AGM35 Lead-Acid Battery
  • ‎50 pounds weight

The Odyssey ODP-AGM35 Performance Series AGM Battery is an incredibly reliable and robust power source that delivers unparalleled performance.

This product will ONLY work with generators with EXACT dimensions of 8.25 x 6.89 x 7.48 inches AND a voltage of 12 Volts. It is an INCREDIBLY powerful AND lightweight device, weighing ONLY 32 pounds. 

A notable feature of this product is its sealed, maintenance-free battery, ensuring that you don’t have to fret about any leak or corrosion-related problems.

If you’re searching for a durable and low-maintenance power solution. This solution is suitable for use in your vehicle or any other equipment and guarantees dependable performance without any hassle. Choosing this option for your power needs is a clear and effortless decision.


  • A perfect alternative for you Generac Battery
  • More powerful than the original.


  • The price is higher than other brands but not than Generac.
Most Powerful

DieHard Silver Battery: 26R Group Size, 575 CCA Best Lightweight

8.5Out of 10
  • Made by DieHard Battery
  • 575 – 720 Cold Cranking Amps
  • 12 Volts DC
  • Model 26R, with a weight of 28.41 lb

The DieHard Silver Battery is designed for bigger appliances and perfectly fits the Generac 22kW generator. This dependable power supply is available in a BCI Group Size of 26R, which matches the exact size of the generator.

You can rely on this starter to power up your generator even in cold weather; its Cold Cranking Amperage of 575A and Cranking Amperage of 720A. It also has a Reserve Capacity of 81 minutes, which provides plenty of time to operate crucial appliances during unexpected situations.

This battery operates at 12.0 volts and weighs 28.41 pounds, making it simple to handle and install. Using the DieHard Silver Battery, you can trust that your Generac generator will always be prepared to power your home when necessary.


  • Good replacement for General 20KW Generator
  • Affordable price
  • High power


  • Always check the dimensions of your battery slot.
Budget Friendly

EverStart Acid Battery, 26R 12 Volt, 540 CCA Budget Friendly

8.5Out of 10
  • Made by EverStart Battery
  • 540 Cold Cranking Amps
  • 12 Volts DC
  • Model 26R
  • ‎1-year free replacement warranty

The EverStart Acid Battery with 26R 12 volts and 540 CCA is the perfect solution for your Generac 22kw generator. Not only is it reliable, but it’s also budget-friendly.

In addition, you can enjoy the advantage of a one-year free replacement warranty, reassuring you. This battery boasts 540 cold-cranking amps, ensuring a reliable start even in chilly temperatures. Moreover, its weight of only 38.2 lbs makes it effortless to handle and install. 

If you are searching for a reliable and affordable battery, the EverStart Acid Battery 26R is ideal.


  • 1-year free replacement warranty
  • Dependable power at a value price


  • This item is discontinued, so a warranty may not be applicable in some states.
Best Performance

Duracell Automotive Battery, Group Size 26R

8.5Out of 10
  • Made by Duracell Battery
  • 550 Cold Cranking Amps
  • 12 Volts DC
  • Model 26R
  • ‎3-year free replacement (disposal fees and taxes may apply)

If you want a reliable 12V battery for your Generac 22kW generator, light truck, or van, there’s only one option you should consider – the Duracell Automotive Battery with a Group Size 26R. 

This battery is specifically designed to withstand even the harshest weather conditions, ensuring that it will keep powering your equipment without fail. The Duracell Automotive Battery with a Group Size 26R and experience the dependable power you need! 

This battery has impressive durability and long-lasting performance, ensuring it will power your generator for an extended period. 

It boasts a Cold Cranking Amps (CCA) of 540 at 0 degrees Fahrenheit, making it highly efficient in starting your engine, even on chilly winter mornings. 

You can trust this battery to provide reliable performance for an extended period.

This battery has a high Cranking Amps (CA) of 665 at 32 degrees Fahrenheit, making it a reliable choice for your vehicle. It also has a Reserve Capacity of 80, ensuring your vehicle runs smoothly. To give you peace of mind, it comes with a 36-month warranty that includes free replacements.


  • Great Brand Reputation
  • The exact size as Generac 22kW requires


  • Only available for Samsclub’s members

What size Battery do I need for my Generac 22kW Generator?

What size Battery do I need for my Generac 22kW

We’re here to help you make the best choice for your Generac 22kW generator so it can run smoothly. Generac recommends the group 26R or group 35AGM battery as they meet the minimum cold cranking amps (CCA) needed. Rest assured, we’ll help you find the perfect battery to keep your generator running.

If you own a Generac generator, you must use a group 26R battery with dimensions of 8 3/16 x 6 13/17 x 7 3/4 inches and a voltage of 12 volts. Should you require a higher minimum cold cranking amp (CCA) of 650, a group 35AGM battery measuring 9 1/16 x 6 7/8 x 8 7/8 inches will be mandatory. It is imperative to note that both batteries are strictly 12-volt.

If you follow Generac’s advice and choose a battery that meets the recommended CCA and size requirements, your generator will start reliably even in tough conditions. This smart decision will give you peace of mind and ensure your generator performs consistently over time.

Importance of Choosing the Right Battery for Your Generator

Ensuring you have a dependable battery for your Generac 22kW generator is essential to maintaining an uninterrupted power supply. The battery is a backup during power outages to keep your generator operating smoothly. Choosing the appropriate battery capacity is one of the main factors to consider.

The power your generator can store and distribute is determined by its battery capacity. A higher capacity battery will ensure your Generac generator’s easy start while you need it. 

Make sure your battery fits into the battery slot of your generator. The Generac 22kW generator requires a battery size of 26R.

It is important to consider the battery’s compatibility with your Generac 22kW generator. Selecting a battery for your generator model guarantees smooth integration and optimal performance.

It is imperative to consider durability when selecting a battery. Severe weather and other challenging circumstances can cause power outages, and a robust battery is essential to withstand such situations. 

Choosing a battery crafted from top-notch materials that can endure extreme temperatures and vibrations will guarantee reliable functionality in crucial times.

Different Types of Batteries for Generac 22kW Generator

Various battery options can be used with Generac 22kW generators, each with pros and cons. Let’s take a closer look at the most popular types.

1. Lead-Acid Batteries: Lead-acid batteries are the most common and traditional generator batteries. They are reasonably priced and provide reliable performance in capacity and durability. However, they require regular maintenance, such as checking electrolyte levels and ensuring adequate ventilation. There are two types of lead-acid batteries: flooded lead-acid (FLA) and valve-regulated lead-acid (VRLA).

2. Lithium-Ion Batteries: Recently, lithium-ion batteries have become increasingly popular due to their high energy density, long lifespan, and hassle-free operation. These batteries are lighter and more compact than lead-acid batteries, making them a great choice for portable generators. Despite their higher upfront cost, their longer lifespan can compensate for it in the long run.

3. AGM (Absorbent Glass Mat) Batteries: AGM batteries are a specific type of VRLA battery that incorporates a fiberglass mat to contain the electrolyte. These batteries are completely sealed and require no maintenance, which makes them ideal for people who prefer a no-fuss battery solution. Compared to traditional lead-acid batteries, AGM batteries have a longer lifespan and can withstand vibration and shock.

4. Gel Batteries: Gel and AGM batteries share similarities, but the former uses gel electrolytes instead of fiberglass mats. Gel batteries provide the same benefits as AGM batteries, including hassle-free maintenance and resistance against vibrations. Nevertheless, gel batteries are not as widely available as AGM batteries and may come at a higher cost.

When selecting a battery, it’s important to consider your needs, budget, and preferences. Factors like lifespan, capacity, maintenance requirements, and cost should all be considered before deciding.

You may like to read: Quick Fix to Generac Generator fault Codes

Factors to Consider When Selecting a Battery

think twice before selecting battery for your generator

When selecting a battery for your Generac 22kW generator, it’s crucial to consider various factors to ensure optimal performance and durability. Remember these essential points:

1. Battery Capacity: When selecting a battery for your generator, it’s important to consider its capacity, measured in ampere-hours (Ah). This determines how much power the battery can store and deliver and how long it can sustain your generator’s load during an outage. To choose the right battery, consider your power consumption needs and the runtime required. Selecting a battery with adequate capacity to meet your needs is important.

2. Compatibility: Before purchasing a battery for your Generac 22kW generator, ensure it is compatible with your specific model. You can do this by checking the manufacturer’s recommendations or consulting a professional to ensure optimal integration and efficiency.

3. Durability: It’s possible to experience power outages in difficult situations or during severe weather. To prepare, selecting a battery that can withstand harsh temperatures, vibrations, and other environmental factors is a good idea. You can guarantee steady performance and extended use by choosing a dependable battery.

4. Lifespan: When choosing a battery, it’s important to consider its expected lifespan. Generally, lithium-ion batteries have a longer lifespan than traditional lead-acid batteries. However, it’s important to note that proper maintenance and usage patterns can also impact the battery’s longevity.

5. Maintenance Requirements: When choosing a battery, it’s important to consider whether you prefer one that requires regular maintenance, such as checking electrolyte levels, or one that is maintenance-free. Additionally, consider your ability to perform any necessary maintenance tasks before making a final decision.

6. Price: The cost of batteries can differ greatly based on their type, capacity, and brand. To find the best option, set a budget and look at choices that fit within it while considering the battery features you require.

When selecting a battery, it is essential to consider your unique requirements and preferences.

A Step-By-Step Guide to Replacing the Battery in Your Generator

Step by step guide to install new battery

If you need to replace the battery in your Generac 22kW generator, don’t worry! It’s a simple process that can be done with just a few basic tools and without any advanced technical knowledge. Just follow these easy step-by-step instructions to ensure a seamless battery replacement:

1. Safety First: Before beginning any work on your generator, turn it off and disconnect it from the power source. Also, remember to wear proper safety equipment like gloves and safety glasses to protect yourself.

2. Locate the Battery: To find the battery in your Generac 22kW generator, open up the engine cover and locate it inside.

3. Disconnect the Old Battery: To begin, first disconnect the negative (-) terminal of the battery. You can use a wrench or socket set to loosen and remove the nut. Once the negative terminal is disconnected, follow the same steps to disconnect the positive (+) terminal.

4. Remove the Old Battery: Please handle the removal of the old battery with care, as batteries can be heavy. Lift it out of the compartment slowly and place it aside for proper disposal according to local regulations.

5. Prepare the New Battery: Before installing the new battery, carefully check for any damage or defects. Make sure it meets the same voltage and capacity specifications as your old battery.

6. Install the New Battery: Please be cautious when placing it into the designated compartment, ensuring it is firmly and securely seated. Begin by connecting the positive terminal, sliding it onto the battery post, and tightening the terminal nut. Afterward, repeat the same process for the negative terminal.

7. Test the Battery: After securely installing the new battery, switch on the generator and check if it functions properly. Verify that it starts smoothly and performs according to expectations.

8. Dispose of the Old Battery: If you still have it, please dispose of it properly by taking it to a recycling center or contacting a local battery retailer for the appropriate disposal options.

With these simple and easy-to-follow instructions, you can effortlessly replace the battery in your Generac 22kW generator and guarantee an uninterrupted power source.

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Maintenance Tips for Prolonging Battery Life

Maintanance guide

Proper maintenance is essential to ensure your Generac 22kW generator battery lasts long and performs well. Here are some tips:

1. Regular Inspections: It’s important to regularly check the battery for any signs of damage, leakage, or corrosion. If you see any corrosion on the battery terminals, use baking soda and water to clean them. Make sure the terminals are tightened and secured properly.

2. Keep the Battery Charged: If you don’t use your generator often, it’s important to keep the battery charged. Lead-acid batteries can lose charge over time, which can cause a decrease in their capacity. To prevent this, consider using a battery maintainer or trickle charger to keep the battery charged.

3. Avoid Deep Discharges: If you want to prolong the lifespan of your battery, it’s advisable to refrain from deep discharges. It’s recommended to recharge the battery before its charge level goes below 50%. Keeping an eye on the battery’s charge level and recharging it when needed is crucial in enhancing its longevity.

4. Ensure Proper Ventilation: During its operation, generators generate heat, which is essential for the battery’s health. Ensure the generator’s engine compartment has sufficient airflow to avoid excessive heat buildup.

5. Follow Manufacturer’s Guidelines: It is important to always consult the manufacturer’s guidelines and recommendations for maintaining your battery. These instructions are specifically tailored to your battery model and provide helpful tips for its upkeep.

Following these maintenance tips, you can keep your Generac 22kW generator battery in excellent condition. This will ensure that you have dependable power during any outages.

Generator batteries, like any other electronic device, may experience occasional problems. To help you resolve these issues, we’ve compiled a list of common battery-related problems and troubleshooting tips.

1. Battery not Holding a Charge: If your battery is not holding a charge or discharging quickly, it may indicate a faulty battery or a bigger issue with the generator. To start, examine the battery connections for any loose or corroded terminals. If the connections are secure, it may be necessary to replace the battery.

2. Battery not Starting the Generator: If your generator’s battery is fully charged but fails to start, the problem might be caused by a faulty starter motor or ignition system. To fix this issue, refer to the user manual for troubleshooting steps or seek help from a professional for repairs.

3. Battery Leaking or Corroded: If you notice any leakage or corrosion on your battery or terminals, it is crucial to take immediate action. Clean the affected areas with baking soda and water, and ensure the terminals are securely fastened. If the leakage persists, it may be necessary to replace the battery.

4. Battery not Recharging: If you’re having trouble recharging your battery, it might be caused by a malfunction in the charging system or an issue with the voltage regulator of the generator. It’s advisable to seek help from a qualified technician to identify and resolve the problem.

5. Battery Lifespan Significantly Reduced: If you have noticed a significant decrease in your battery’s lifespan, it may be caused by improper maintenance, deep discharges, or extreme operating conditions. Reviewing your maintenance practices and ensuring you adhere to the manufacturer’s guidelines is crucial. If the issue persists, you might consider upgrading to a better-quality battery.

Suppose you encounter any issues with your generator’s battery that you cannot fix yourself. In that case, it is recommended that you seek help from a certified technician who specializes in generator upkeep and restoration.

Final Thoughts and Recommendations

We understand the importance of keeping your Generac 22kW generator running smoothly during outages. We want to help you choose the best battery to ensure a continuous power supply. Consider factors such as battery capacity, compatibility, durability, and maintenance requirements to make an informed decision. Rest assured that we’re here to assist you every step of the way.

When it comes to your Generac generator, you want to ensure it’s running at its best. Researching reputable battery brands is crucial for optimal performance and compatibility. To ensure a longer lifespan for your generator, following a step-by-step guide on replacing and maintaining the battery is essential. 

If you encounter any battery-related issues, troubleshooting them and seeking professional assistance is recommended. You have various options for purchasing your replacement battery, such as authorized dealers, online retailers, local battery stores, and specialty generator shops. Take the time to find the best place for you and your generator’s needs.

By choosing the appropriate battery for your Generac 22kW generator, you can eliminate most starting problems associated with the generator.

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