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Poco M2 Pro 3.85V 4900mAh Replacement Battery Li-Polymer

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From $30.99 USD $38.99
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Fits Poco M2 Pro smartphone; replaces original 3.85V Li-Polymer cell for full charge capacity restoration.
3.85V nominal output and 4900mAh capacity deliver the OEM power profile; underperforming original cells show sudden shutdowns at 20–30% charge remaining.
Connector seats flat against the phone's battery contact rail; locking tab secures the cell and prevents accidental disconnection during use.
We bench-tested this cell against the M2 Pro fuel gauge IC—BMS accepted the handshake on power-up with no voltage cutoff errors or early termination.
On first use after installation, disable fast charging for one complete discharge-charge cycle so the coulomb counter recalibrates against the new cell's discharge curve before high-current charging resumes.
Delivery time

This product ships directly from our Manufacturer's Warehouse and is usually delivered within 7 – 10 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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Fresh Battery, Worth the Wait

To provide the highest-quality replacement battery, we ship this battery directly from the manufacturer rather than from aging warehouse inventory. This means delivery may take a little longer, but it helps ensure you receive a fresh battery with better performance, a longer lifespan, and greater reliability.

Estimated delivery: 7–10 business days
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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

3.85V

Amp

4900mAh

Poco M2 Pro — 3.85V Li-Polymer Replacement Battery

This is a 3.85V, 4900mAh Li-Polymer replacement battery for the Poco M2 Pro smartphone. It fits the original battery bay directly and restores primary power to the device. Capacity is rated at 18.87Wh, matching the original cell specification.

  • Poco M2 Pro fit: The M2 Pro uses a specific battery bay measuring 93.65 × 64.10 × 4.50mm with a matching connector pinout. This cell matches those dimensions and the voltage rail the charge IC expects. A mismatched voltage or connector layout would prevent the BMS from communicating with the phone's power management unit.
  • Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the M2 Pro platform. The BMS handshake completed correctly, fast charge was accepted after the first full cycle, and the fuel gauge IC tracked state-of-charge without erratic jumps.
  • First-cycle fuel gauge recalibration: After installation, disable fast charging and complete one full discharge-charge cycle at standard rate. This gives the fuel gauge IC a clean discharge curve to calibrate against the new cell before high-current charging begins on an uncalibrated reference.

Why the M2 Pro reports wrong battery percentage after a cell swap

The M2 Pro uses a coulomb counter in the fuel gauge IC that tracks charge based on the original cell's discharge curve. When a new cell goes in, that stored curve no longer matches the actual cell chemistry, so the reported percentage drifts — sometimes wildly. The fix is one complete discharge down to device shutdown, followed by a full charge to 100% at the standard rate. After that cycle, the IC has a fresh reference and percentage reporting stabilises.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the threshold the modem or display controller needs under load — even though the fuel gauge still shows charge remaining. The new cell's internal resistance behaves differently from the worn original, so voltage sags faster under peak draw. The fuel gauge IC hasn't recalibrated yet and misses the real cutoff point. Run one full discharge-charge cycle; if shutdowns persist, check that the resting cell voltage sits above 3.7V before starting the cycle.

Compatible Models

M2 Pro

Technical Specifications

Voltage3.85V
Amp Hours4900mAh
Capacity4900mAh
Rate18.87Wh
Net Weight65.6g /2.31 oz
Gross Weight115.6g /4.08 oz
Approximate Weight115.6g /4.08 oz
Dimension 93.65 x 64.10 x 4.50mm

Product Highlights

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

Frequently Asked Questions

My M2 Pro won't turn on at all after the replacement battery sat in a drawer for a few months — is it dead?

Most likely the cell dropped below 2.5V in storage and the BMS locked out to prevent damage. Connect the phone to a wall charger — not a PC port — and leave it for 20–30 minutes without pressing any buttons. The charge IC will trickle current into the cell until voltage recovers enough for the BMS to release. Once the charging indicator appears on screen, the cell is recovering; charge it fully before first boot.

Fast charging stopped working on my M2 Pro after I fitted the new battery — the phone just charges slowly now.

The USB-PD or Poco fast-charge protocol requires a handshake between the charger, the charge IC, and the battery BMS. On the first cycle after a cell swap, the BMS sometimes defaults to standard charging until it completes one full charge cycle and confirms cell health. Charge the phone to 100% at the slow rate, then discharge it fully, and fast charging should re-engage on the next charge. If it still doesn't trigger, confirm you're using the original Poco adapter — third-party chargers often fail the protocol negotiation.

The battery percentage on my M2 Pro jumps around — it shows 45%, then suddenly drops to 12% without any real drain.

The fuel gauge IC is reading against the old cell's discharge curve, which no longer matches the new cell. The coulomb counter loses accuracy mid-cycle and the displayed percentage snaps to a new estimate when the IC corrects itself. Do one full uninterrupted discharge — let the phone run down to automatic shutdown — then charge to 100% at the standard rate without interruption. After that cycle the IC has a calibrated curve and percentage reporting will track accurately.

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