Harley-Davidson ® FX,FL (Softail) (1991 - '25) Motorcycle Batteries

The Softail® family is the ultimate expression of Harley-Davidson style, hiding modern suspension within a classic "hardtail" silhouette. For the iconic Fat Boy and Heritage Classic to the aggressive Breakout and Softail Slim, get a battery that can withstand significant engine heat and the high-torque requirements of the 80ci Evolution, Twin Cam, and Milwaukee-Eight engines.

At Battery Mart, we lead our Softail selection with the Big Crank ETX20L. Proudly manufactured in the USA by East Penn (Deka), this battery is our favorite battery for Softail riders. It is engineered with Absorbent Glass Mat (AGM) technology, providing 310 Cold Cranking Amps (CCA) in a leak-proof, maintenance-free package that is ready to install the moment it hits your doorstep.

Why the Big Crank ETX20L is Built for Softails:

  • Vibration Proof: Internal components are reinforced to handle the unique harmonics of the Softail chassis.
  • High Starting Torque: 310 CCA ensures your Big Twin turns over quickly, every time.
  • Molded-In Terminals: Patented terminal design prevents the "loose bolt" issues common with cheaper, multi-fit batteries.
  • Direct Fit: Engineered to the exact dimensions of your factory battery box for a 1991–2025 fitment guarantee.

The Softail® family is the ultimate expression of Harley-Davidson style, hiding modern suspension within a classic "hardtail" silhouette. For the iconic Fat Boy and Heritage Classic to the aggressive Breakout and Softail Slim, get a battery that can withstand significant engine heat and the high-torque requirements of the 80ci Evolution, Twin Cam, and Milwaukee-Eight engines.

At Battery Mart, we lead our Softail selection with the Big Crank ETX20L. Proudly manufactured in the USA by East Penn (Deka), this battery is our favorite battery for Softail riders. It is engineered with Absorbent Glass Mat (AGM) technology, providing 310 Cold Cranking Amps (CCA) in a leak-proof, maintenance-free package that is ready to install the moment it hits your doorstep.

Why the Big Crank ETX20L is Built for Softails:

  • Vibration Proof: Internal components are reinforced to handle the unique harmonics of the Softail chassis.
  • High Starting Torque: 310 CCA ensures your Big Twin turns over quickly, every time.
  • Molded-In Terminals: Patented terminal design prevents the "loose bolt" issues common with cheaper, multi-fit batteries.
  • Direct Fit: Engineered to the exact dimensions of your factory battery box for a 1991–2025 fitment guarantee.
NOCO NLP20 12V, 600A Lithium Powersport Battery
Item #: NLP20  |    

NOCO NLP20 12V, 600A Lithium Powersport Battery

NOCO NLP20 12V, 600A Lithium Powersport Battery

Item #: NLP20
 
Voltage: 12.8 Volt / 7 Ah / 600 Amps (Peak)
• LiFePO4
• Dimensions: 6.9" / 3.4" / 5.1"
• Weight: 5.24 lbs
• Warranty: 5 Year Limited
Price:
$179.95
Price: $179.95
QTY:
Outback’r H13 Folding HD Multi-Tool for Harley-Davidson Motorcycles
Item #: OH13  |    

Outback’r H13 Folding HD Multi-Tool for Harley-Davidson Motorcycles

Outback’r H13 Folding HD Multi-Tool for Harley-Davidson Motorcycles

Item #: OH13
 
• Weight: 1.06 lbs
• 60 Day Return
Price:
$19.95
Price: $19.95
QTY:
Topdon TopScan Moto Harley-Davidson Diagnostic Scan Tool & Cable Kit
Item #: TSMHARLEY  |    

Topdon TopScan Moto Harley-Davidson Diagnostic Scan Tool & Cable Kit

Topdon TopScan Moto Harley-Davidson Diagnostic Scan Tool & Cable Kit

Item #: TSMHARLEY
 
• Weight: 1.00 lbs
• Warranty: 1 Year
Price:
$124.99
Price: $124.99
QTY:
EarthX ETZ14C Lithium Snowmobile & Powersports Battery (Scratch & Dent)
Item #: OB-MC1  |    

EarthX ETZ14C Lithium Snowmobile & Powersports Battery (Scratch & Dent)

Made in USA MADE IN USA

EarthX ETZ14C Lithium Snowmobile & Powersports Battery (Scratch & Dent)

Item #: OB-MC1
 
Voltage: 13.2 Volt / 6.8 Ah / 330 CCA / 690 PCA
• LiFePO4
• Dimensions: 5.9" / 3.4" / 4.5"
• Weight: 2.50 lbs
• Warranty: 1 Year Factory Direct
Reg. Price: $259.00
SALE Price: $209.95
You save: $49.05!
QTY:
Topdon TopScan Moto Honda, Kawasaki, Suzuki, Yamaha & Kymco Diagnostic Kit
Item #: TOPSCANMOTO  |    

Topdon TopScan Moto Honda, Kawasaki, Suzuki, Yamaha & Kymco Diagnostic Kit

Topdon TopScan Moto Honda, Kawasaki, Suzuki, Yamaha & Kymco Diagnostic Kit

Item #: TOPSCANMOTO
 
• Weight: 1.00 lbs
• Warranty: 1 Year
Price:
$109.99
Price: $109.99
QTY:

Softail Battery Guide: Reliability for the Modern Cruiser

Choosing a battery for a Softail requires attention to detail. Because the battery is tucked away beneath the seat or oil tank, you need a unit that is 100% maintenance-free and heat-resistant. The 1991-2025 FX and FL Softail models utilize the "20L" footprint, a compact yet powerful size that has become the industry standard for high-performance cruisers.

The USA-Made Advantage

The Big Crank ETX20L is manufactured by East Penn in Lyons, Pennsylvania. Unlike many imported batteries that use lead-calcium alloys susceptible to vibration failure, the Big Crank uses premium lead-calcium-tin alloy grids. This results in a battery that holds its charge longer during storage and recovers faster after a long day of riding.

Frequently Asked Questions

Which Softail models does this battery fit?

This category covers the vast majority of Softail models from 1991 through 2025. This includes the FXST (Standard), FLSTF (Fat Boy), FLSTC (Heritage Classic), FLSTN (Deluxe), FXSTB (Night Train), and modern Milwaukee-Eight models like the FXBB (Street Bob) and FXBR (Breakout).

Is the ETX20L the same as the battery from the Harley dealer?

The Big Crank ETX20L is manufactured by East Penn, the same company that produces many of the original equipment batteries found in Harley-Davidson showrooms. When you buy a Big Crank, you are getting the same American-made quality and AGM technology at a significant savings.

Can I use a Lithium battery in my Softail?

Yes, Lithium (LiFePO4) is a popular upgrade for Softail owners looking to reduce weight or increase cranking speed. Lithium batteries are significantly lighter than the standard AGM and offer a very high "cranking punch." If you choose this route, ensure you are using a lithium-compatible charger to prevent damage to the cells.

How do I know when my Softail battery is failing?

Common signs include a "stutter" or slow crank when you press the start button, your lights dimming significantly during startup, or the battery failing to hold a charge after a few days of sitting. Because the Softail's security system draws a small amount of power constantly, we recommend using a smart maintainer like a Battery Tender to maximize lifespan.

Model Fitment Reference

This category is the definitive source for batteries fitting the following Harley-Davidson Softail sub-models (1991-2025):

  • FLST Series: Heritage Softail Classic, Fat Boy, Softail Deluxe, Heritage Special.
  • FXST Series: Softail Standard, Night Train, Softail Custom, Springer Softail.
  • FLS / FXBB / FXLR: Softail Slim, Street Bob, Low Rider, Low Rider S/ST.
  • FXBR / FXFB: Breakout, Fat Bob.