STX20L-BS Harley-Davidson FLSTF Softail Fat Boy (1991-2014) High-Performance Battery
Couldn't load pickup availability
⚠️ Quick Reminder
🔹 Please ensure the original battery model number is listed in our product description and that your device model number matches for compatibility.
🔹 We only supply the batteries shown in the images. Device images are provided for reference only.
📸 Send Your Battery Photo / Unsure? Expert Help
Snap a photo or video of your battery and send it to us. We'll identify the exact replacement—fast and hassle-free. Our team has helped thousands of customers find the right battery quickly and easily.
POST YOUR IMAGE
Battery Care Guide
Battery Care Guide
Battery Usage and Maintenance Guidelines 🔋
Please read the following instructions carefully before using your new battery. Proper adherence will help ensure optimal performance and extended service life.
1. Cordless Phones, PDAs, and Power Tools (NiMH, NiCd, Lithium-Ion) 📱
Initial Charge
- Fully charge the battery overnight prior to first use.
Conditioning (First 2–6 Charge Cycles)
- Operate the device until the battery reaches approximately 20% capacity.
- Avoid premature recharging.
- Do not allow the battery to fully discharge during the initial cycles.
Post-Conditioning
- Recharge the battery only when necessary.
- These batteries are capable of approximately 500 charge cycles:
- Once daily → ~500 days
Twice daily → ~250 days
Note: Even a partial recharge is considered a full cycle.
2. Sealed Lead Acid (SLA) Batteries 💡
- No conditioning required.
- Maintain the battery in a fully charged state; avoid complete discharge.
- Capable of 300–400 charge cycles.
- Expected service life: 2–3 years, depending on usage conditions.
3. Laptop Batteries (Lithium-Ion) 💻
Initial Charge
- Fully charge the battery overnight prior to first use.
Conditioning (First 2–6 Charge Cycles)
- Charge fully, then discharge to approximately 20% capacity.
- Avoid complete discharge, as some devices may not detect a fully drained battery.
Post-Conditioning
- Minimize frequent plugging and unplugging.
- Allow the battery to discharge moderately at least once per month to maintain optimal performance.
- Occasional cycling is recommended to sustain battery health.
Professional Recommendation
Adhering to these guidelines will enhance battery longevity and ensure reliable performance.
For further assistance regarding your battery or order, our customer support team is available to provide guidance.
Delivery and Shipping
Delivery and Shipping
⚡ Everything You Need to Know About Shipping with BatteryWeb (USA)
We know reliable delivery matters when you need power fast. Here’s how BatteryWeb makes shipping easy across the USA:
🚚 Shipping & Delivery
Most orders ship next business day (some products like sealed lead acid may take a little longer).
Same-day shipping available if you order before 11:59 AM (delivery depends on the carrier).
We ship nationwide using FedEx, UPS, USPS, DHL, and regional ground carriers.
Shipping costs are calculated automatically at checkout based on weight, distance, and carrier.
Transit times shown are estimates only (business days, no weekends/holidays).
🌍 Shipping Restrictions
Lithium batteries cannot be shipped by USPS or air. They must go via FedEx Ground, UPS Ground, or DHL Ground.
PO Box deliveries are only available via USPS.
At this time, we do not ship lithium batteries to Puerto Rico. NiMH, NiCd, and Alkaline can be shipped.
📦 Important Notes
Double-check your shipping address! If an incorrect address is used and the order is returned, re-shipping costs are the buyer’s responsibility.
If a product is temporarily out of stock, we’ll notify you right away with the expected restock date—or issue a refund if you prefer.
💲 Currency & Pricing
All prices are shown in USD.
Orders shipped outside the USA may be subject to local taxes, customs fees, or import duties. These are the buyer’s responsibility.
⚡ At BatteryWeb, we’re committed to getting your batteries delivered quickly, safely, and affordably—so you’ll always have the power you need, when you need it.
Disclaimer
Disclaimer
⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.
🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
🔹 Our products are generic replacement parts and are not affiliated with, endorsed by, or manufactured by the original equipment manufacturers (OEMs).
Volts & Amps
12 Volts | 18 Ah
Terminal Type
Nut & Bolt
STX20L-BS Replacement Battery for Harley-Davidson FLSTF Softail Fat Boy (1991-2014)
Upgrade your Harley-Davidson FLSTF Softail Fat Boy (1991-2014) with the STX20L-BS replacement battery engineered for reliable starting power, improved performance, and everyday durability. Designed to meet or exceed OEM specifications, this high-performance battery delivers dependable starts in a wide range of riding conditions while offering a maintenance-free, spill-proof build that reduces hassle and increases safety on the road.
Key Specifications
- Model: STX20L-BS
- Compatible Model: Harley-Davidson FLSTF Softail Fat Boy (1991-2014)
- Brand: SigmasTek
- Voltage: 12 Volts
- Capacity: 18 Ah
- Terminal Type: Nut & Bolt
- Design: Maintenance-free, Spill-proof
- Construction: Durable to withstand vibration and extreme temperatures
- Performance Note: High CCA rating for reliable cold-weather starting
- Compliance: Meets or exceeds OEM specifications
Benefits
- Durability: Built to withstand motorcycle vibration, heat, and the rigors of frequent use so you get consistent starts and fewer replacements.
- Long life: Maintenance-free construction and quality components deliver reliable service life, making this a true long-lasting battery option for riders.
- High performance: A high CCA rating improves cold-weather starts and delivers the immediate cranking power needed for heavy-displacement Harley engines.
- Safety and convenience: Spill-proof, leak-proof design and maintenance-free operation eliminate the need for acid refilling and reduce risk during installation and transport.
- OEM-level fit and compatibility: Guaranteed fit for the FLSTF Softail Fat Boy (1991-2014) ensures plug-and-play replacement without modification.
- Versatile applications: While ideal as a motorcycle starting battery, this reliable power source also suits emergency power applications, portable tools, and backup power systems where dependable 12V supply is required.
When you need a dependable, high-performance battery replacement for your Harley, the STX20L-BS is engineered to deliver reliable starts, rugged durability, and hassle-free maintenance. Choose this long-lasting battery to keep your Fat Boy ready to ride—purchase now and enjoy dependable power on every trip.
-
Voltage
-
Amp Hours
-
Terminal Type
-
Polarity
-
Length (in.)
-
Width (in.)
-
Height (in.)
-
Weight (lb.)
-
Warranty
-
Type
-
Manufacturer
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.