5 Best Batteries for Generac 22kW Generators Revealed
The best batteries for Generac 22kW generators depends on your needs. The Interstate Batteries 12V 9Ah is best for standard backup power with proven reliability, while the Mighty Max 12V 35AH GEL excels at extreme temperature performance. For cold weather protection, the Cold Weather Kit for Generac stands out with automatic temperature control that keeps your battery and oil warm in freezing conditions.
Your Generac 22kW generator needs a reliable battery to start when you need it most. Whether you’re dealing with harsh winters or need long-lasting backup power, choosing the right battery makes all the difference.
Quick Comparison Table
| Product | Battery Type | Capacity | Temperature Protection | Warranty | Special Features |
|---|---|---|---|---|---|
| Cold Weather Kit for Generac | Heating System | N/A | Auto on/off 40-55°F | N/A | UL certified, plug-and-play |
| Interstate Batteries 12V 9Ah | AGM SLA | 9Ah | Wide temp range | 12 months | High-rate discharge, spill-proof |
| Ankiwi Battery Heater Kit | Heating System | N/A | Auto on/off 40-55°F | N/A | UL certified, easy install |
| Mighty Max 12V 35AH GEL | GEL | 35Ah | Extreme temp rated | Standard | Slower discharge, vibration resistant |
| Mighty Max 12V 18AH SLA | AGM SLA | 18Ah | High/low temp rated | 12 months | UL certified, deep discharge |
Best Batteries for Generac 22kW Generators
1. Cold Weather Kit for Generac – Complete Battery and Oil Heating System
Best for: Generator owners in cold climates who need reliable cold-weather starting protection.
Key Features:
| Feature | Details |
| Compatibility | 9kW-22kW air-cooled generators |
| Temperature Control | Auto on/off 40-55°F |
| Safety Certification | UL certified |
| Installation | Plug-and-play design |
| Components | Battery pad and oil heater |
The Cold Weather Kit for Generac is the best heating solution for generator owners facing freezing temperatures. This dual-system kit replaces OEM parts 7101 and 7102, providing both battery warming and oil heating.
The UL-certified design gives you peace of mind with proven safety standards. Both heating pads integrate seamlessly with your existing generator components.
Automatic temperature control means you never have to remember to turn it on or off. The system activates at 40°F and shuts off at 55°F, protecting your battery and keeping oil at optimal viscosity.
Installation is straightforward with plug-and-play connections. The battery pad sits under your battery while the oil heater wraps around your oil filter.
This kit extends your generator’s life by reducing cold-start stress and preventing battery degradation. It’s an essential upgrade for anyone in regions with harsh winters.
Pros:
- Automatic temperature control
- UL safety certified
- Easy plug-and-play installation
- Dual heating system
Cons:
- Requires 2008 or newer models
- Higher upfront cost
2. Interstate Batteries 12V 9Ah – Trusted High-Rate Backup Battery
Best for: Generator owners seeking a proven, maintenance-free battery from a trusted brand.
Key Features:
| Feature | Details |
| Voltage/Capacity | 12V 9Ah |
| Technology | AGM VRLA sealed |
| Dimensions | 5.94″ x 2.56″ x 3.70″ |
| Terminal Type | Nut and bolt |
| Warranty | 12 months performance |
The Interstate Batteries 12V 9Ah is the best replacement battery for Generac generators when you want proven reliability. This high-rate SLA battery delivers fast, critical power when your generator needs to start.
AGM VRLA technology makes this battery completely spill-proof and maintenance-free. The sealed design eliminates the risk of acid leaks and prevents over-pressurization.
Superior plate-to-terminal connections ensure rapid power delivery during startup. This battery excels in both float standby applications and high-demand situations.
Interstate’s 70-year reputation backs this battery with rigorous quality testing. The 12-month performance warranty demonstrates their confidence in the product.
The compact dimensions fit most Generac 22kW generator battery compartments perfectly. Installation is straightforward with standard nut and bolt terminals.
Pros:
- Trusted 70-year brand reputation
- Spill-proof sealed design
- High-rate discharge capability
- 12-month warranty included
Cons:
- Lower capacity than larger options
- Mid-range price point
3. Ankiwi Battery Heater Kit – Affordable Cold Weather Protection
Best for: Budget-conscious buyers who need reliable cold weather protection for their generators.
Key Features:
| Feature | Details |
| Replaces | Generac 7101 and 7102 |
| Auto Control | On at 40°F, off at 55°F |
| Compatibility | 9kW-22kW air-cooled generators |
| Certification | UL certified |
| Installation | Plug-and-play with instructions |
The Ankiwi Battery Heater Kit is the best value option for cold weather generator protection. This replacement kit matches OEM specifications while saving you money.
The dual-component system includes both battery warming and oil filter heating. UL certification ensures the kit meets strict safety standards for outdoor use.
Automatic temperature control activates heating when temperatures drop below 40°F. The system shuts off above 55°F to prevent overheating and conserve energy.
Installation is simple with plug-and-play integration into existing generator components. Detailed instructions and online videos make setup easy even for beginners.
This kit protects your investment by ensuring reliable cold-weather starts. It extends both battery and oil filter life by maintaining optimal operating temperatures.
Pros:
- Lower price than competitors
- UL safety certified
- Automatic temperature control
- Easy installation process
Cons:
- Less established brand name
- Limited warranty information
4. Mighty Max 12V 35AH GEL Battery – Premium Long-Life Power
Best for: Generator owners who want maximum capacity and superior extreme-temperature performance.
Key Features:
| Feature | Details |
| Type | 12V 35Ah GEL |
| Technology | Thick gel paste |
| Discharge Rate | Slower self-discharge |
| Temperature Range | Extreme hot/cold rated |
| Durability | Vibration and shock resistant |
The Mighty Max 12V 35AH GEL Battery is the best premium option for maximum capacity and longevity. This GEL battery outperforms standard AGM batteries in extreme conditions.
The thick gel paste technology provides superior safety with no spillage risk. This design resists vibrations and shocks better than liquid-based batteries.
GEL batteries retain their charge longer when not in use thanks to slower self-discharge rates. This means your generator will be ready even after extended periods of inactivity.
Extreme temperature performance makes this battery ideal for harsh climates. It delivers consistent power whether you’re in scorching heat or freezing cold.
The 35Ah capacity provides extended runtime and reliable starting power. Mighty Max’s reputation for quality ensures you’re getting a dependable product.
Pros:
- Highest capacity option
- Superior temperature performance
- Slower self-discharge rate
- Enhanced vibration resistance
Cons:
- Higher price point
- Heavier than smaller batteries
5. Mighty Max 12V 18AH SLA Battery – Budget-Friendly Reliable Power
Best for: Budget-conscious buyers who need a dependable battery with good capacity.
Key Features:
| Feature | Details |
| Voltage/Capacity | 12V 18Ah |
| Technology | SLA/AGM spill-proof |
| Dimensions | 7.12″ x 3″ x 6.5″ |
| Mounting | Any position |
| Warranty | Full one year |
The Mighty Max 12V 18AH SLA Battery is the best budget option that doesn’t sacrifice quality. This UL-certified battery delivers reliable performance at an affordable price.
AGM spill-proof construction allows mounting in any position without leak concerns. The sealed design resists shocks and vibrations common in generator applications.
High discharge rate capability ensures strong starting power when your generator kicks on. The battery performs well in both high and low temperature conditions.
Deep discharge recovery means this battery bounces back after heavy use. Standard nut and bolt terminals make installation quick and straightforward.
A full one-year warranty backs this battery with confidence. It’s an excellent choice for those wanting dependable power without premium pricing.
Pros:
- Most affordable battery option
- UL certified quality
- Good 18Ah capacity
- Full one-year warranty
Cons:
- Lower capacity than premium options
- No accessories included
How to Choose Batteries for Generac 22kW Generators
Battery Capacity and Type
Battery capacity determines how much power your generator has for starting and running accessories. Look for at least 9Ah for basic needs, but 18-35Ah provides better performance and longevity.
AGM batteries offer maintenance-free operation and good all-around performance. GEL batteries cost more but provide superior extreme-temperature performance and longer charge retention.
Cold Weather Performance
Cold temperatures dramatically reduce battery performance and oil viscosity. If you live in areas with freezing winters, consider a heating kit alongside your battery.
Automatic heating systems turn on at 40°F and off at 55°F without manual intervention. This protection ensures reliable starts even in harsh conditions and extends battery life significantly.
Physical Dimensions and Compatibility
Measure your generator’s battery compartment before purchasing. Most Generac 22kW generators use standard sizes, but verification prevents installation headaches.
Check terminal type as well—most use nut and bolt connections. Ensure your chosen battery matches your generator’s manufacturing year and model specifications.
Warranty and Brand Reputation
A solid warranty indicates manufacturer confidence in their product. Look for at least a one-year performance warranty on replacement batteries.
Established brands like Interstate have decades of proven reliability. Newer brands like Mighty Max offer good value but have shorter track records.
Maintenance Requirements
Sealed AGM and GEL batteries require zero maintenance—no water additions or terminal cleaning. This convenience makes them ideal for standby generators that sit unused for extended periods.
Spill-proof designs allow any-position mounting and eliminate acid leak concerns. VRLA technology prevents dangerous gas buildup and over-pressurization.
Frequently Asked Questions
What size battery does a Generac 22kW generator need?
Most Generac 22kW generators use 12-volt batteries ranging from 9Ah to 35Ah capacity. The specific size depends on your model year and configuration, but 18Ah provides good performance for most applications.
Do I need a battery heater for my Generac generator?
You need a battery heater if you live in areas where temperatures regularly drop below 40°F. Cold weather significantly reduces battery performance and oil viscosity, making starts difficult or impossible without heating protection.
How long do Generac generator batteries last?
Generac generator batteries typically last 3-5 years with proper maintenance. Factors affecting lifespan include climate, usage frequency, and whether you use cold weather protection in freezing temperatures.
Can I use a car battery in my Generac generator?
You should not use a car battery in your Generac generator. Generators require deep-cycle or AGM batteries designed for standby applications, while car batteries are optimized for short, high-current starting bursts.
What’s the difference between AGM and GEL batteries?
AGM batteries use absorbed glass mat technology and cost less, while GEL batteries use thick gel paste for superior extreme-temperature performance and slower self-discharge. GEL batteries last longer but cost more upfront.
Final Thoughts
The Interstate Batteries 12V 9Ah offers the best balance of reliability and value for most Generac 22kW generator owners. For cold climates, add the Ankiwi or Cold Weather Kit for essential protection.
Consider your local climate, budget, and capacity needs when choosing. GEL batteries provide premium performance, while AGM batteries offer excellent value for moderate conditions.
Don’t wait for battery failure during an outage—replace aging batteries proactively and add heating protection if you face freezing temperatures.