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SigmasTek  |  SKU: BW-4251

APC BACK-UPS ES BK350E1 UPS High Performance Replacement Battery

Sale price $16.99 USD Regular price $24.15
Shipping calculated at checkout.

➤ Absorbent Glass Mat (AGM) technology for enhanced durability

➤ High rate discharge design supports emergency power needs

➤ Maintenance-free and spill-proof construction for safety

➤ U.L. recognized and CE certified for guaranteed quality

➤ 1-year warranty ensures reliable, factory-fresh performance


📦🚀 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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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 | 7.5 Ah

Terminal Type

F2

Replacement APC BACK-UPS ES BK350E1 Battery — Compatible with APC BACK-UPS ES BK350E1

Designed for complete compatibility with the APC BACK-UPS ES BK350E1, this replacement UPS battery delivers reliable power continuity, dependable performance, and the peace of mind you need during outages. Engineered to meet or exceed OEM SLA battery specifications, this high-performance UPS battery is an ideal swap for aging or failed cells in your BK350E1, restoring runtime and protecting connected devices with a maintenance-free, spill-proof design.

Key Specifications

  • Absorbent Glass Mat (AGM) Technology
  • High Rate Discharge Design
  • Maintenance-Free Design with Spill Proof Construction
  • U.L. Recognized and CE Certified
  • Brand New, Factory Fresh
  • 1 Year Warranty
  • Brand: SigmasTek
  • Voltage: 12 Volts
  • Capacity: 7.5 Ah
  • Terminal: F2
  • Compatible Model: APC BACK-UPS ES BK350E1
  • Meets/Exceeds OEM SLA battery specifications

Benefits

This replacement UPS battery is built for durability and long life. The AGM construction provides a robust internal structure that tolerates high-rate discharge cycles while remaining maintenance-free. You get a long-lasting battery solution that resists leaks and requires no watering or periodic maintenance. As a high-performance UPS battery, it supports clean, consistent power delivery to sensitive electronics, helping prevent data loss, hardware damage, and costly downtime.

Typical applications include UPS systems (especially the APC BACK-UPS ES BK350E1), emergency power supply setups, and battery-powered tools that demand reliable spurts of energy. The high rate discharge design makes this battery suitable for sudden draws during power outages and ensures connected equipment continues to operate long enough for safe shutdowns or continued operation until power is restored.

Safety and quality certifications, including U.L. recognition and CE marking, confirm compliance with industry standards. Backed by a one-year warranty and delivered factory fresh, this replacement battery minimizes the risk inherent in older or degraded cells and restores UPS performance quickly and affordably.

Ready to restore reliable backup power to your APC BACK-UPS ES BK350E1? Purchase this high-performance, long-lasting replacement UPS battery today and get dependable protection for your equipment.


Payment & Security

Payment methods

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