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SigmasTek  |  SKU: BW-1543

Best Power Unity UT4K High Performance Replacement Battery Set

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

➤ Four 12V 35AH batteries in one package for Best Power FERRUPS MX 1KVA UPS units

➤ Maintenance-free AGM sealed lead acid chemistry for dependable power supply

➤ UL certified for guaranteed safety and performance compliance

➤ Compatible NB terminals allow direct swap with original batteries

➤ Fast shipping and 1-year warranty included for reliable service


📦🚀 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.

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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

Best Power Unity UT4K Replacement Batteries (4 × 12V 35AH, NB) - Compatible with Best Power Unity UT4K

Replace the full battery set in your Best Power Unity UT4K with this factory-matched bundle of four replacement UPS batteries. This package includes all 4 batteries required for proper operation and is built using Absorption Glass Mat (AGM) sealed battery technology for dependable performance and safety. UL certified and designed to meet or exceed the original manufacturer specifications, these batteries provide the consistent runtime and durability expected from a high-performance UPS battery solution for the Best Power Unity UT4K.

Key Specifications

  • Compatible UPS Model: Best Power Unity UT4K
  • Volts: 12 V (each battery)
  • Amp Hours: 35 AH (each battery)
  • Terminal: NB (Nut & Bolt)
  • Chemistry: SLA (Sealed Lead Acid)
  • Technology: AGM (Absorption Glass Mat) Sealed Battery
  • Package contains: 4 batteries (price includes all 4 batteries)
  • Weight: 98.8 Lbs (set)
  • Length: 7.72 In
  • Width: 5.14 In
  • Height: 6.14 In
  • Warranty: 1-year Warranty
  • Brand / Spec Sheet Reference: SigmasTek / Best Power
  • Shipping Methods: UPS Ground and USPS (ships in 1 business day for in-stock items)
  • Guaranteed compatibility with original battery set

Benefits

  • Robust Durability: AGM construction ensures a sealed, maintenance-free battery that resists vibration and offers reliable service in demanding UPS environments.
  • Long Service Life: These long-lasting batteries are sized and specified to match the Best Power Unity UT4K, reducing the frequency of replacements and maintaining consistent backup availability.
  • High Performance: 35AH capacity per battery provides substantial runtime for equipment racks, servers, and critical infrastructure, delivering the performance expected from a high-performance UPS battery set.
  • Safe and Certified: UL certification and OEM-grade specifications give you confidence in safe operation for emergency power, telecom, and data center applications.
  • Complete Set: The package contains all 4 batteries required by the UT4K, simplifying ordering and ensuring correct match and installation.
  • Versatile Applications: Ideal for UPS backup systems, emergency power arrays, telecom cabinets, small UPS racks, and stationary power tools where a reliable multi-battery configuration is required.
  • Installation Guidance: Install the new batteries in the original configuration and reuse existing cables and hardware; verify dimensions prior to ordering if needed.
  • Support Available: Contact customer service via email, chat, or toll-free at (800) 657-1303 for assistance with fitment or technical questions.

Ensure uninterrupted protection for your Best Power Unity UT4K by ordering this complete set of replacement UPS batteries today. Fast shipping, UL certification, and a 1-year warranty make it easy to upgrade your backup power system now.


Payment & Security

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