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
Enersys  |  SKU: BW-13310

National Battery NBX12-500 High Performance Compatible UPS Replacement Battery

Sale price $582.20 USD Regular price $764.42
Shipping calculated at checkout.

➤ Compatible replacement for National Battery NBX12-500 UPS systems

➤ High capacity 12 Volts, 145 Ah for extended backup power

➤ Durable internal threaded terminals for secure connections

➤ Reliable Enersys brand quality ensures long battery life

➤ Ideal for uninterrupted power supply and emergency use


📦🚀 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 | 145 Ah

Terminal Type

Internal Thread

National Battery NBX12-500 - Compatible with Enersys

The National Battery NBX12-500 replacement battery is a trusted 12 Volt, 145 Ah unit made for compatibility with Enersys UPS systems. This replacement battery provides steady capacity and dependable terminal performance, making it an excellent choice for protecting critical equipment. When you need a reliable, long-lasting battery that performs in both standby and cyclic roles, the NBX12-500 offers the stability and quality expected in high-performance battery replacements.

Key Specifications

  • Product Model: NBX12-500
  • Replacement Type: UPS Battery (Replacement)
  • Compatible Brand: Enersys
  • Brand (Replacement): National Battery
  • Voltage: 12 Volts
  • Capacity: 145 Ah
  • Terminal Type: Internal Thread

Benefits

The NBX12-500 is built for durability and consistent service life. As a long-lasting battery, it offers strong cycle performance and dependable float capability, reducing the need for premature replacement. Its internal thread terminals provide secure, low-resistance connections that help maintain system reliability under heavy use and during emergency discharges. This high-performance battery is designed to meet the demands of critical power applications.

Durability: Robust casing and reliable internal terminals help the NBX12-500 withstand the stresses of industrial and data center environments. Longevity: With a 145 Ah capacity at 12 Volts, this unit gives extended backup time for medium-sized UPS banks and systems where dependable reserve power is required. Performance: Engineered to deliver steady voltage under load and efficient recharge characteristics, this replacement battery supports both float and cyclic charging strategies.

Typical applications include uninterruptible power supplies, emergency power systems, telecom infrastructure, server room backups, and industrial control battery banks. It’s also suitable for renewable energy storage systems and other installations where a reliable replacement battery with known capacity and terminal type is necessary for safe, effective operation.

Ensure continuous protection for your critical systems—choose the National Battery NBX12-500 replacement battery for a high-performance, long-lasting battery solution compatible with Enersys. Purchase today to secure dependable backup power and minimize downtime.


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.