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SigmasTek  |  SKU: BW-4922

APC BACK-UPS ES350U UPS High Performance Replacement Battery

Sale price $19.19 USD Regular price $27.82
Shipping calculated at checkout.

➤ Replacement for APC ES BACK-UPS ES350U UPS unit

➤ High rate discharge design for short-term high power output

➤ Valve regulated, spill-proof, and low self-discharge

➤ UL recognized, CE certified with 1-year warranty

➤ Tested to meet or exceed OEM specifications


📦🚀 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 | 3.5 Ah

Terminal Type

F2

SigmasTek SP12-3.5HR Replacement for APC ES BACK-UPS ES350U — Compatible with APC ES BACK-UPS ES350U

This SigmasTek SP12-3.5HR replacement UPS battery is built to restore the APC ES BACK-UPS ES350U to reliable operation, offering carefully tested performance and factory-fresh reliability. As a purpose-designed 12 Volt 3.5 Ah SLA battery for APC ES BACK-UPS ES350U units, it functions as a high-performance UPS battery and a cost-effective alternative to OEM packs. Use your existing cables and hardware to install this replacement UPS battery quickly and safely.

Key Specifications

  • Compatible UPS Model: APC ES BACK-UPS ES350U
  • Manufacturer / Brand: SigmasTek (SP12-3.5HR)
  • Voltage: 12 Volts
  • Capacity: 3.5 Ah
  • High Rate Discharge Design: Yes
  • Construction: Valve Regulated Spill Proof (sealed)
  • Low Self-discharge: Yes
  • Vibration Resistance: High
  • Certifications: U.L. Recognized and CE Certified
  • Condition: Brand New, Factory Fresh
  • Warranty: 1 Year Warranty
  • Terminal Type: F2

Benefits

This high-performance UPS battery is engineered for durability and dependable short-term high power output thanks to its high rate discharge design. The valve-regulated, spill-proof construction eliminates maintenance and keeps your equipment safe, while low self-discharge ensures the battery retains capacity when idle. These features combine to make a long-lasting battery ideal for UPS units, emergency power systems, and battery-powered tools.

Users replacing the APC ES BACK-UPS ES350U can expect consistent voltage under load, strong vibration resistance for stable performance in varied environments, and factory testing that verifies the battery meets or exceeds OEM specifications. This replacement UPS battery is a practical upgrade for anyone seeking reliable runtime and quality certifications such as U.L. recognition and CE marking.

Our experienced staff tests each battery and is ready to assist you if you need guidance. Orders for in-stock items are typically shipped within 24 hours, letting you get back to full protection quickly.

Restore your APC ES BACK-UPS ES350U today—purchase this SigmasTek SP12-3.5HR replacement UPS battery for a reliable, long-lasting battery solution and fast shipping.


Payment & Security

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