Welcome to our store. Your trusted source for batteries and power solutions. Learn more

For support or quotes: sales@batteryweb.com
WELCOME5
BatteryWeb

BN5V Poco X7 Replacement Battery 3.91V 5000mAh

Up to 19% off
New arrival
From $38.99 USD $47.99
Shipping calculated at checkout.
Fits Poco X7 smartphone; replaces OEM battery BN5V directly.
3.91V output at 5000mAh capacity restores full charge cycles on the X7 without voltage sag under load.
Connector seats into the original slot with standard flex-tab orientation; no physical modification needed.
We bench-tested this cell in an X7 reference unit — BMS accepted the new pack on first insert, fuel gauge IC showed factory calibration sync within two discharge cycles.
On first use after installation, run one complete discharge-to-shutdown cycle without fast charging enabled; this lets the coulomb counter recalibrate against the new cell's actual voltage curve before USB-PD pushes current.
Visa Mastercard American Express PayPal Apple Pay Google Pay Shop Pay Discover Klarna Afterpay Stripe
✦

Check that your old battery model number and device model to match our description. This makes sure they work together.

✦

We ship your order same day if you buy it before 4 PM EST.

Warranty

Let customers speak for us

from 11 reviews

Product is exactly as described and arrived quickly

Robert Jones
Rocket ES4-12 Compatible Replacement Battery

It took a bit longer than expected, likely due to the holiday season, but that was understandable. So far, the battery seems to be working well!

Linda M.
MGE UPS Systems Pulsar EX 1500RT Compatible Replacement Battery By Bright Way

Excellent substitute for the original, appearing to be the perfect replacement.

Alberto J.
APC SMART-UPS RT SURTA3000RMXL3U UPS High Performance Replacement Battery Set

It was what i was looking for. Support is fast

Jaswal
WAHEGURUG - RADHASWAMI

Fast service

Mark Casias
BatteryWeb

Perfect fit

Mark Casias
STX20L-BS Battery for Harley Softail FLS FLST 1991-2017 High Performance

Works Perfectly!!

Ben Benson
Invacare 220 Scooter High Performance Medical Replacement Battery Set

Send Your Battery Photo

Expert Technician 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 BATTERY IMAGE
Product & Solutions Expert

Product & Solutions Expert

✉ sales@batteryweb.com

🔹 10+ Years Battery Experience 🔹 Fast & Accurate Identification

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

3.91V

Amp

5000mAh

Poco X7 — 3.91V Li-Polymer Replacement Battery (BN5V)

This is a 5000mAh Li-Polymer cell rated at 3.91V, built to the BN5V specification for the Poco X7 smartphone. It replaces a degraded or failed original battery that no longer holds a usable charge. Capacity is 19.55Wh, matching the factory cell's energy rating.

  • Poco X7 fit: The X7 uses the BN5V cell with a specific flex connector pinout and BMS handshake tied to the phone's charge IC. This cell matches that pinout and communicates correctly with the fuel gauge IC so the OS can track state of charge accurately.
  • Bench tested on actual hardware: We ran a full discharge-to-charge cycle on the X7 platform and confirmed the BMS negotiates charge current correctly with the onboard charge IC. Voltage held steady under screen and modem load with no unexpected cutoff events.
  • Fuel gauge recalibration after install: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC build an accurate discharge curve against the new cell before high-current charging begins on an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the replacement cell

This happens because the fuel gauge IC is still calibrated to the old cell's voltage curve. A fresh Li-Polymer cell has a steeper voltage drop at the low end of its discharge range. The phone reads the voltage, compares it against a stale curve, and hits a low-voltage shutdown threshold earlier than expected. Run two full discharge-to-charge cycles without fast charging — by the second cycle the coulomb counter re-anchors to the new cell and shutdowns at low percentage stop.

USB-PD fast charge not negotiating on the first cycle after replacement

On the first charge after a cell swap, the charge IC may default to a conservative trickle or standard 5V charge rate and refuse to step up. This is the BMS protecting an uncalibrated cell — it does not yet have a verified capacity reading to calculate safe C-rate limits. Disconnect the cable, power the phone fully off, then reconnect — most users see full fast-charge negotiation restore by the second plug-in. If it does not, complete one full slow cycle first, bringing the cell down to around 3.2V before recharging.

Compatible Models

X7

Replaces Part Numbers

BN5V

Technical Specifications

Voltage3.91V
Amp Hours5000mAh
Capacity5000mAh
Rate19.55Wh
Gross Weight80g /2.82 oz
Approximate Weight80g /2.82 oz

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 Poco X7 shows 25% battery and then shuts off completely — is the new cell faulty?

The cell is almost certainly fine. The fuel gauge IC in the X7 is still reading the old cell's discharge curve, so it triggers a low-voltage shutdown earlier than the actual cell warrants. Run two full charge-discharge cycles with fast charging turned off. After the second cycle, the coulomb counter recalibrates to the new cell's curve and the early shutdowns stop.

The battery percentage on my X7 is jumping around — it went from 60% to 43% in two minutes without me doing anything.

That's the fuel gauge IC losing track of state of charge on an uncalibrated cell. The X7's coulomb counter builds its capacity model from recorded charge and discharge history — on a brand-new cell, that history is blank. Erratic percentage jumps are normal for the first one or two cycles. Drain the phone down to around 3.2V under normal use, then charge it fully and slowly — one cycle is usually enough to stabilise the readings.

After fitting the BN5V, my X7 gets noticeably warm near the battery during the first charge — should I stop charging it?

Mild warmth on the first charge is expected. A new high-impedance Li-Polymer cell has slightly elevated internal resistance compared to a broken-in cell, so the charge IC dissipates a little more heat as it pushes current through it. If the phone is warm but not hot to the touch, continue charging. If it becomes uncomfortable to hold or exceeds what you'd expect from normal fast charging, switch to a standard 5V charger for that first cycle to reduce charge current into the uncalibrated cell.

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.

Related Products

Poco X7 Replacement Battery, 3.91V, 5000mAh, Li-Polymer 1

Engineered for Performance. Built to Last.

Check out our top-rated selection of reliable products built to last. We offer high-quality options that deliver consistent performance for all your needs.

Our Collections