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SigmasTek  |  SKU: BW-1561

Best Technologies FERRUPS FD 4.3KVA High Performance Replacement Battery Set

Sale price $366.99 USD Regular price $524.08
Shipping calculated at checkout.

➤ Package contains 4 batteries for complete replacement

➤ Uses AGM sealed battery technology for durability and performance

➤ Guaranteed compatibility with original Best Technologies UPS units

➤ UL certified for safety and reliability

➤ 1-year warranty included for peace of mind


📦🚀 FAST SHIPPING: Usually ships same day if ordered before 2 PM EST

⚠️ 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.
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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

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: 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 | 35 AH

Terminal Type

Nut & Bolt

Replacement UPS Batteries for Best Technologies FERRUPS FD 4.3KVA - 12V 35AH (NB)

Keep your Best Technologies FERRUPS FD 4.3KVA running strong with a full set of four replacement UPS batteries designed for compatibility, performance and reliability. These 12V 35AH sealed AGM batteries deliver the dependable backup power you expect from a high-quality replacement UPS battery. Sourced and tested to meet or exceed original manufacturer specifications and UL certified for safety, this pack restores runtime and protects critical loads when mains power fails. Whether you manage servers, networking gear, or critical telecom equipment, this high-performance UPS battery set brings reliable emergency power to your system.

Key Specifications

  • Package contains 4 batteries
  • SLA Chemistry
  • AGM Technology
  • Guaranteed compatibility with original battery set
  • 1-year Warranty
  • Volts: 12 V
  • Amp Hours: 35 AH
  • Weight: 98.8Lbs
  • Length: 7.72 In
  • Width: 5.14 In
  • Height: 6.14 In
  • Terminal: NB
  • SigmasTek UPS Batteries Spec Sheets
  • UL (Underwriters Laboratories) certified
  • Shipping Methods: UPS Ground and USPS
  • We ship in 1 business day for all in-stock items

Benefits

This replacement UPS battery pack is built with Absorbent Glass Mat (AGM) technology to provide a maintenance-free, leak-proof design and excellent charge acceptance. As a high-performance UPS battery solution, it offers consistent output under load and reliable recharge characteristics that prolong usable life. The sealed SLA chemistry and UL certification give confidence for safe installation in data centers, server rooms, telecom closets and home office UPS systems.

Durability and long life are core advantages: AGM construction resists vibration and tolerates frequent charge/discharge cycles better than many other designs, making it an ideal long-lasting battery for routine backup and emergency power needs. Typical applications include primary UPS backup for servers, network infrastructure, point-of-sale systems, emergency lighting, and portable tools that rely on steady DC power during outages. Because this set is guaranteed to match the original battery configuration, you can reinstall with your existing cables and hardware in the same original layout.

Installation reminders: verify your existing battery dimensions before ordering, as manufacturers can change specifications without notice. If you prefer a single battery instead of the full four-pack, please visit the UPS Batteries by V and AH section to select individual units. If you need assistance, our customer service team is available via email, chat or by calling toll free at (800) 657-1303.

Replace worn or failing cells with this trusted, long-lasting battery option and restore dependable runtime to your Best Technologies FERRUPS FD 4.3KVA. Order now to get fast shipping and the peace of mind that comes with a UL-certified, high-performance replacement UPS battery pack backed by a 1-year warranty.


Payment & Security

Payment methods

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