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AT&T Unite Pro W-6 Replacement Battery 3.7V 2400mAh

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From $27.99 USD $34.99
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Fits AT&T Unite Pro, Unite Pro 4G, Unite Pro 4G LTE, and Aircard 781S; replaces OEM part W-6.
3.7V 2400mAh Li-ion cell delivers 8.88Wh; matches original capacity for full session runtime on hotspot.
Connector slides straight into battery slot with single locking tab; orientation marked on device housing.
Bench testing showed clean BMS handshake on first insertion; no voltage sag under dual WiFi and cellular draw.
On first extended session with multiple connected devices, keep the hotspot in open air — cellular radio draws maximum power in weak signal areas, and the aluminum housing needs airflow to prevent thermal stress on the new cell.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

Delivery and Shipping

🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.

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.

Voltage

3.7V

Amp

2400mAh

AT&T Unite Pro / Aircard 781S — 3.7V Li-ion Replacement Battery (W-6)

This 3.7V 2400mAh Li-ion battery replaces the factory cell in the AT&T Unite Pro, Unite Pro 4G, Unite Pro 4G LTE, and Aircard 781S mobile hotspots. It fits the OEM battery tray directly and connects to the device BMS without modification. Capacity matches the original spec at 8.88Wh.

  • Unite Pro and Aircard 781S compatibility: These models share the same 3.7V battery rail, connector pinout, and BMS handshake protocol — one cell covers the full range listed. No firmware differences affect charging behavior across these variants.
  • Bench tested on actual hardware: We cycled this battery through charge and discharge on a Unite Pro 4G LTE unit. The BMS accepted the cell without fault flags, held cutoff at 3.0V on the low end, and reached full charge termination at 4.2V without thermal events.
  • Ventilation during extended hotspot sessions: Keep the device flat on an open surface — not in a bag or pocket — during long sessions. When connected devices are far from the hotspot, the cellular radio runs at peak transmit power continuously, generating heat that accelerates cell wear.

Why the Unite Pro drops connected devices mid-session on a new battery

The Unite Pro runs both a cellular modem and a 2.4/5GHz Wi-Fi radio simultaneously. When all connection slots fill up and the cellular signal is weak, combined current draw spikes sharply. If the cell's internal resistance is elevated — common in aged batteries — voltage sags below the modem's minimum operating threshold, triggering a radio reset that drops all connected devices. A fresh cell with lower internal resistance holds voltage stable under that combined load.

Unite Pro shows full charge icon but dies quickly after unplugging

This happens when the original battery has lost capacity through shallow cycling — frequent top-ups without full discharge cycles compress the active electrode material over time. The device fuel gauge still reads the stored charge curve but the actual deliverable capacity has dropped significantly. Replacing the cell resets this — the new 2400mAh cell will show accurate state-of-charge readings after one complete charge-to-discharge cycle. Run it down to the low-battery warning once, then charge fully to 4.2V to calibrate the gauge.

Compatible Models

Unite Pro Unite Pro 4G Unite Pro 4G LTE Aircard 781S

Replaces Part Numbers

W-6 5200080

Technical Specifications

Voltage3.7V
Amp Hours2400mAh
Capacity2400mAh
Rate8.88Wh
Net Weight70.9g /2.50 oz
Gross Weight106g /3.74 oz
Approximate Weight106g /3.74 oz
Dimension 77.30 x 55.00 x 9.60mm

Product Highlights

  • Brand: AT&T
  • Manufacturer: CS
  • Series: X-Longer
  • Color: Black
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My Unite Pro hotspot keeps disconnecting everyone on it even though the battery bar shows half charge — why does this happen with a new battery installed?

A half-charge reading doesn't guarantee stable voltage under load. When the modem and Wi-Fi radio both run at full draw — especially in a weak signal area — current demand spikes and voltage can sag below the modem's cutoff threshold even with charge remaining. Check whether drops happen more often in low-signal locations; that confirms radio-induced voltage sag rather than a faulty cell. If drops persist in good signal conditions, verify the battery connector is fully seated.

The Unite Pro battery drains noticeably faster when I'm in an area with weak cell signal — is that a battery problem or a network problem?

That's a network problem the battery has to absorb. When cellular signal is poor, the modem automatically increases transmit power to maintain the connection, pulling significantly more current from the cell. Multiple connected devices compound this — each active Wi-Fi client adds to the radio's processing load on top of the elevated modem draw. The battery itself isn't the cause, but a degraded original cell will fail faster under this condition than a fresh 2400mAh replacement.

My AT&T Unite Pro won't turn on at all after sitting unused for several months — is the battery dead?

Most likely the cell discharged below the minimum boot voltage during storage. Li-ion cells self-discharge slowly over time, and if the device sat long enough, the battery dropped below the threshold the BMS requires to allow a power-on sequence — typically around 3.0V. Plug the hotspot into the charger and leave it for at least 30 minutes before attempting to power it on; some BMS circuits need a trickle pre-charge cycle before they'll release the main charge path. If the LED stays dark after 30 minutes of charging, the original cell is likely unrecoverable and needs replacing.

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