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SigmasTek  |  SKU: BW-16576

FIAMM FGH21803 High Performance Compatible Replacement Battery 12.66 lb

11% off
Sale price $55.99 USD Regular price $62.99
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Compatible replacement for FIAMM FGH21803 SLA battery
Advanced Absorbent Glass Mat (AGM) technology for reliable performance
Maintenance-free and spill-proof design for hassle-free use
U.L. Recognized and CE Certified for safety and quality assurance
Brand new, factory fresh with 1-year warranty included
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Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

Delivery and Shipping

🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.

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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.


Volts & Amps

12 Volts | 18 Ah

Terminal Type

Nut & Bolt

FIAMM FGH21803 Replacement Battery — Compatible with FIAMM FGH21803

Specifically made to replace the FIAMM FGH21803, this replacement battery offers stable, maintenance-free power based on Absorbent Glass Mat (AGM) technology and sealed lead acid (SLA) construction. The FGH21803 replacement is designed for reliability, safety, and easy installation with nut & bolt terminals. If you need a high-performance battery that’s also a long-lasting battery solution, this unit provides OEM-level compatibility and a best-price guarantee.

Key Specifications

  • Compatible Model: FIAMM FGH21803
  • Battery Type: Sealed Lead Acid (SLA)
  • Technology: Absorbent Glass Mat (AGM)
  • Voltage: 12 Volts
  • Capacity: 18 Ah
  • Terminal Type: Nut & Bolt
  • Replacement Brand: SigmasTek
  • Certifications: U.L. Recognized and CE Certified
  • Condition: Brand New, Factory Fresh
  • Design: Maintenance-Free with Spill Proof Construction
  • Warranty: 1 Year Warranty

Benefits

The FIAMM FGH21803 replacement battery is built to deliver dependable performance across a broad range of backup and motive applications. AGM technology ensures low internal resistance and better charge acceptance, supporting quick recharge and steady delivery under load—qualities that make this a high-performance battery for mission-critical installations. Its sealed, maintenance-free design minimizes upkeep and reduces the risk of spills or corrosion, increasing safety for indoor and rack-mounted setups.

This long-lasting battery is well-suited for UPS units, emergency lighting, security and alarm systems, medical devices, and other essential equipment that requires continuous or standby power. Nut & bolt terminals enable secure connections and reliable conductivity for both temporary replacements and permanent installations. The U.L. recognition and CE certification further confirm the battery meets recognized safety standards.

Shipped brand new and factory fresh, the FGH21803 replacement includes a 1 Year Warranty to help protect your investment and provide confidence in performance. If you’re replacing an aging FIAMM battery or stocking spares for critical systems, this replacement battery balances cost and reliability.

Secure uninterrupted power now — order the FIAMM FGH21803 replacement battery today. Click to buy and ensure your systems have a dependable, long-lasting source of power.

Technical Specifications

Voltage12 Volts
Amp Hours18 Ah
Terminal TypeNut & Bolt
Length (in.)7.13
Width (in.)3.0
Height (in.)6.59
Weight (lb.)12.65

Product Highlights

  • Brand Replacement : FIAMM FGH21803 Battery
  • Manufacturer: SigmasTek
  • Product Type: SLA Batteries
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

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