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

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.