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

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

Vivo IQOO 11 Pro Replacement Battery B-X9 7.74V 2700mAh

Up to 19% off
New arrival
From $49.99 USD $61.99
Shipping calculated at checkout.
Fits Vivo iQOO 11 Pro and replaces OEM battery part number B-X9 directly.
7.74V and 2700mAh capacity matches the original cell's voltage and charge storage for full device runtime.
Connector seats flush into the iQOO 11 Pro battery slot with standard polarity orientation and mechanical lock tabs.
We bench-tested this Li-Polymer cell on the iQOO platform — BMS accepted the new pack on first insert, voltage ramp stable through full charge cycle.
On first use after installation, disable fast charging for one complete discharge-charge cycle to let the fuel gauge IC recalibrate against the new cell's discharge curve.
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

7.74V

Amp

2700mAh

Vivo IQOO 11 Pro — 7.74V Li-Polymer Replacement Battery (B-X9)

This is a 7.74V, 2700mAh (20.9Wh) Li-Polymer replacement battery for the Vivo IQOO 11 Pro smartphone. OEM part number B-X9. It slots directly into the IQOO 11 Pro chassis and connects to the same flex cable and BMS handshake points as the original cell.

  • IQOO 11 Pro platform fit: The IQOO 11 Pro uses a dual-cell Li-Polymer pack running a 7.74V nominal rail. The connector pinout, BMS communication lines, and physical cell dimensions match the original B-X9 spec — no adapter or wiring modification needed.
  • Bench tested on actual hardware: We ran the B-X9 through charge and discharge cycles on the IQOO 11 Pro mainboard. The BMS accepted the cell on first connection, the charge IC initiated correctly, and the fuel gauge IC began tracking coulomb count from cycle one.
  • First-cycle calibration on the IQOO 11 Pro: After installation, disable fast charging for the first full discharge-charge cycle. The fuel gauge IC on the IQOO 11 Pro needs one measured cycle at standard current to map the new cell's discharge curve before FlashCharge pushes high current into an uncalibrated state of charge register.

Sudden shutdown at 20–30% on the IQOO 11 Pro after a cell swap

This happens when the fuel gauge IC is still using the discharge curve from the old, degraded cell. The new cell has a different voltage-versus-capacity slope, so the IC calls 20% remaining when the actual cell voltage is already near its low cutoff under modem and display load. The phone shuts off because the real cell voltage drops below the safe floor — not because the replacement cell is defective. One full discharge down to automatic shutdown followed by a full charge resets the coulomb counter and resolves it.

IQOO 11 Pro not powering on after the replacement battery sat in storage

Li-Polymer cells self-discharge during storage. If the B-X9 cell dropped below approximately 2.5V per cell during transit or shelf time, the BMS enters a lockout state and blocks normal boot. Connect the phone to a wall adapter — not a PC port — and leave it for 15 to 20 minutes without pressing the power button. The charge IC trickle-charges the cell back above the BMS recovery threshold, after which the phone should respond normally. If the screen stays dark past 25 minutes, check that the charger is delivering at least 5V 2A.

Compatible Models

IQOO 11 Pro

Replaces Part Numbers

B-X9

Technical Specifications

Voltage7.74V
Amp Hours2700mAh
Capacity2700mAh
Rate20.9Wh
Gross Weight120g /4.23 oz
Approximate Weight120g /4.23 oz

Product Highlights

  • Brand: Vivo
  • 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 IQOO 11 Pro shows 100% immediately after installing the new B-X9 battery, then drops to 60% within minutes — what's wrong?

The fuel gauge IC is still calibrated to the old cell's discharge curve and cannot accurately track the new cell's capacity profile. This causes erratic percentage jumps until the IC re-learns the new curve. Run one full discharge — use the phone normally until it shuts itself off — then charge to 100% without interruption. After that single cycle the coulomb counter recalibrates and percentage readings stabilise.

FlashCharge stopped working on my IQOO 11 Pro after fitting the replacement battery — it only charges at slow speed now.

On the first cycle after a cell swap, the IQOO 11 Pro's charge IC sometimes withholds the FlashCharge handshake until it confirms the new cell's impedance and temperature response are within safe parameters. This is a one-cycle protection behaviour, not a fault with the B-X9 cell. Complete one full charge at standard speed, then disconnect and reconnect the charger — the FlashCharge protocol should negotiate normally from the second cycle onward. If it still does not, confirm the cable is rated for the current the charger requires.

The IQOO 11 Pro gets noticeably warm near the battery area during the first few charges with the new cell — is that normal?

A new Li-Polymer cell has higher internal impedance than a cell that has been through several formation cycles. The charge IC has to push current into a less broken-in cell, which generates more heat at the contact points and through the cell itself during the first two or three charges. Surface warmth — not hot to the touch — in that region during early cycles is expected and settles as the cell's impedance drops. If the phone becomes too hot to hold comfortably, stop the charge and check that the cable and adapter are matched to the phone's charge spec.

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

Vivo IQOO 11 Pro Replacement Battery, 7.74V, 2700mAh, 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