For questions, quotes, or help finding the right battery, feel free to email us at sales@batteryweb.com

New collections added! Learn more

🎉 First Order Special 🎉

First-time shoppers get 5% OFF on batteries & accessories!

WELCOME5
SigmasTek  |  SKU: BW-5370

Best Technologies FERRUPS FES 850VA UPS High Performance Replacement Battery

Sale price $54.00 USD Regular price $78.30
Shipping calculated at checkout.

➤ Advanced AGM technology for stable and long-lasting power

➤ High rate discharge design for quick energy delivery

➤ Maintenance-free with spill proof construction for safety

➤ U.L. Recognized and CE Certified for quality assurance

➤ Brand new with a 1 year warranty 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.
POST YOUR IMAGE

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 | 18 Ah

Terminal Type

Nut & Bolt

Replacement SigmasTek 12V 18Ah for Best Technologies FERRUPS FES 850VA

This replacement UPS battery is a direct-fit substitute for the Best Technologies FERRUPS FES 850VA, offering dependable, maintenance-free power protection to keep your UPS performing at peak levels. With AGM technology, a high rate discharge design, and factory-fresh quality, this long-lasting battery delivers the reliable performance required for emergency power and critical backup applications.

Key Specifications

  • Compatible UPS model: Best Technologies FERRUPS FES 850VA
  • Battery type: Sealed Lead Acid (SLA) with Absorbent Glass Mat (AGM) Technology
  • Voltage: 12 Volts
  • Capacity: 18 Ah
  • Terminal type: Nut & Bolt
  • Brand: SigmasTek / Best Technologies compatible replacement
  • Design: High Rate Discharge
  • Maintenance: Maintenance-Free, Spill Proof Construction
  • Certifications: U.L. Recognized and CE Certified
  • Condition: Brand New, Factory Fresh
  • Warranty: 1 Year

Benefits

  • Durability and Long Life: Constructed with AGM technology, this replacement UPS battery is built to last and resist the stresses of repeated charge cycles. The sealed design minimizes maintenance and extends useful life for the FERRUPS FES 850VA.
  • High Performance: High rate discharge capability ensures the battery can provide reliable power delivery during urgent, short-duration demands—making it a high-performance UPS battery suitable for sensitive electronics and emergency systems.
  • Safe and Certified: U.L. recognition and CE certification demonstrate compliance with stringent safety standards, providing assurance in mission-critical environments.
  • Versatile Applications: Ideal for UPS systems, emergency power backup, and battery-powered tools, this long-lasting battery supports a wide range of use cases where dependable backup power is essential.
  • Easy Installation: Nut & bolt terminals and confirmed compatibility with Best Technologies FERRUPS FES 850VA simplify replacement, minimizing downtime and service effort.

Get your Best Technologies FERRUPS FES 850VA back to full protection—order this reliable, long-lasting replacement UPS battery today. In-stock, factory-new, and backed by a one-year warranty, it’s the practical choice for dependable backup power. Purchase now to ensure continued protection.


Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • 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.