Welcome to our store. Your trusted source for batteries and power solutions. Learn more

For support or quotes: sales@batteryweb.com

WELCOME5
SigmasTek  |  SKU: BW-14037

FirstPower FP645 Compatible Replacement Battery 1.59 lb

19% off
Sale price $21.99 USD Regular price $26.99
Shipping calculated at checkout.
Absorbent Glass Mat (AGM) Technology for enhanced durability
Maintenance-Free, Spill Proof Design for hassle-free use
U.L. Recognized and CE Certified for guaranteed safety and quality
Brand New, Factory Fresh for reliable performance
1 Year Warranty ensures peace of mind and protection
In stock

— Ready to ship immediately

Free shipping

Visa Mastercard American Express PayPal Apple Pay Google Pay Shop Pay Discover Klarna Afterpay Stripe

Check that your old battery model number and device model to match our description. This makes sure they work together.


We ship your order same day if you buy it before 4 PM EST.

Send Your Battery Photo

Expert Technician 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 BATTERY IMAGE
Product & Solutions Expert

Product & Solutions Expert

✉ sales@batteryweb.com

🔹 10+ Years Battery Experience 🔹 Fast & Accurate Identification

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.

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.


Volts & Amps

6 Volts | 4.5 AH

Terminal Type

F1

FirstPower FP645 Replacement Battery — Compatible with FirstPower FP645

When you need a reliable, compatible power source for your FirstPower FP645, this replacement battery provides the performance and dependability required for backup and everyday use. Engineered to meet or exceed OEM SLA specifications, this long-lasting battery integrates AGM technology, a spill-proof maintenance-free design, and industry certifications to deliver trustworthy operation for a wide range of applications.

Key Specifications

  • Model Compatibility: FirstPower FP645
  • Brand: SigmasTek
  • Voltage: 6 Volts
  • Capacity: 4.5 AH
  • Technology: Absorbent Glass Mat (AGM) Technology
  • Design: Maintenance-Free with Spill Proof Construction
  • Certifications: U.L. Recognized and CE Certified
  • Condition: Brand New, Factory Fresh
  • Warranty: 1 Year Warranty

Benefits

This replacement battery is built to last. AGM technology enhances durability, improves charge efficiency, and helps the battery withstand repeated cycles without premature failure. The maintenance-free, spill-proof construction simplifies handling and installation while reducing the risk of corrosion or leakage. As a high-performance battery, it maintains reliable power output for sensitive devices and systems that require stable voltage.

Typical uses include uninterruptible power supplies (UPS), emergency lighting, security and alarm systems, medical equipment, and portable tools—applications where a long-lasting battery and predictable performance are essential. Safety and quality are validated by U.L. Recognition and CE certification, and the brand-new, factory-fresh unit is covered by a 1 year warranty to protect your investment.

If your FP645 is showing signs of wear or reduced runtime, replace it with this compatible, performance-driven battery to restore dependable operation. It’s an economical and effective alternative to OEM batteries that keeps your equipment running when you need it most.

Act now—purchase this FirstPower FP645 replacement battery today and upgrade to a reliable, long-lasting battery solution for your devices.

Technical Specifications

Voltage6 Volts
Amp Hours4.5 AH
Terminal TypeF1
Length (in.)2.76
Width (in.)1.86
Height (in.)3.94
Weight (lb.)1.59

Product Highlights

  • Brand Replacement : FirstPower FP645 Battery
  • Manufacturer: SigmasTek
  • Product Type: SLA Batteries
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Bancontact
  • Diners Club
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.