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SigmasTek  |  SKU: BW-5791

Alarmnet 7845C High Performance Replacement Battery

Sale price $18.74 USD Regular price $22.62
Shipping calculated at checkout.

➤ Compact size: 3.78 x 0.98 x 2.44 inches

➤ Reliable 12-volt power supply

➤ Lightweight at 1.65 lbs for easy handling

➤ 0.8 Ah capacity ensures consistent performance

➤ Compatible replacement for Alarmnet brand products


📦🚀 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 | 0.8 Ah

Terminal Type

Special Connector

12V 0.8Ah Replacement Battery — Compatible with Alarmnet (SigmasTek)

This 12V 0.8Ah replacement battery is engineered for dependable compatibility with Alarmnet devices and other security equipment that require compact, trustworthy backup power. Built by SigmasTek to match the form factor and electrical characteristics of the original, this long-lasting battery offers stable performance for alarm systems, sensors, and small standby applications. If you need a reliable, maintenance-free replacement battery for your Alarmnet-compatible unit, this high-performance battery delivers value and consistency.

Key Specifications

  • Manufacturer: SigmasTek
  • Brand Replacement: Alarmnet
  • Voltage: 12 Volts
  • Amp Hours: 0.8 Ah
  • Length: 3.78 inches
  • Width: 0.98 inches
  • Height: 2.44 inches
  • Weight: 1.65 lb

Benefits

As a replacement battery designed specifically for Alarmnet-compatible equipment, this cell offers dependable standby power in a compact package. The battery’s construction focuses on high performance in small dimensions, delivering expectations of long life and reliable discharge performance when systems require backup energy. It’s an ideal long-lasting battery for alarm panels, security sensors, emergency lighting circuits, and other low-current standby roles where a compact footprint is required.

Durability is built into the design to withstand repeated charge cycles while minimizing maintenance; this makes installation and long-term ownership simple for both homeowners and service technicians. Although compact, it functions as a high-performance battery for short-duration discharges and steady trickle charge scenarios commonly seen in monitoring systems. Typical applications include UPS monitoring modules, emergency notification devices, security controllers, and portable test tools where a compact 12V backup source is needed.

Installing this replacement battery is straightforward — confirm dimensions and polarity against your existing battery to ensure a correct match. The SigmasTek-made unit is intended to meet or exceed original specifications so you can restore your system quickly and confidently.

Ready to replace your Alarmnet battery? Add this long-lasting, high-performance battery to your cart now to maintain uninterrupted protection and system readiness.


Payment & Security

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