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UTEC V171 Compatible Battery 3.7V 750mAh Li-ion

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Fits UTEC V171, V181, V201, V566 smartphones; replaces original 3.7V lithium-ion pack.
3.7V and 750mAh capacity restore full talk time and standby duration on this device.
Connector and internal contact layout match OEM orientation; no physical modification needed.
We bench-tested this cell on V171 hardware; BMS accepted charge and discharged smoothly through 80% before load test.
On first use after installation, run one complete discharge-charge cycle without fast charging enabled — this recalibrates the fuel gauge IC to the new cell's discharge curve.
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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

750mAh

UTEC V171 / V181 / V201 / V566 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 750mAh Li-ion cell for the UTEC V171, V181, V201, and V566 smartphones. It matches the original cell's dimensions (53.00 × 33.90 × 5.70mm), voltage, and connector footprint. Install it when the original cell no longer holds a charge or the phone shuts down before the screen says it should.

  • V171 / V181 / V201 / V566 compatibility: These four UTEC models share the same battery bay dimensions, 3.7V rail, and connector pinout. One cell fits all four without modification.
  • Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS engaged correctly at both the high-voltage cutoff and the low-voltage floor, with no thermal events during the charge phase.
  • Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the OS starts reporting percentages it can trust.

Sudden shutdown at 20–30% on a replacement cell

A new cell has a slightly different discharge curve than the aged cell the phone's fuel gauge IC was calibrated against. At moderate charge levels, the IC may read 25% while the actual cell voltage has already dropped below what the modem or screen load needs to stay stable. The phone cuts out to protect the hardware — it is not a faulty battery. One full discharge-charge cycle at standard rate recalibrates the coulomb counter and closes the gap between reported and actual state of charge.

Phone won't power on after the replacement cell sat in storage

Li-ion cells self-discharge during storage. If the cell voltage has dropped below approximately 2.5V, the BMS enters lockout mode and blocks any charge current as a protection measure. Connect the phone to a wall charger — not a PC USB port — and leave it for 15 to 20 minutes without pressing the power button. A wall charger delivers enough current to nudge the BMS out of lockout. Once the screen shows the charging indicator, the cell is above the recovery threshold and will charge normally.

Compatible Models

V171 V181 V201 V566

Technical Specifications

Voltage3.7V
Amp Hours750mAh
Capacity750mAh
Rate2.78Wh
Net Weight23g /0.81 oz
Gross Weight48g /1.69 oz
Approximate Weight48g /1.69 oz
Dimension 53.00 x 33.90 x 5.70mm

Product Highlights

  • Brand: UTEC
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My UTEC V171 shows 30% battery but shuts off without warning — is that a fault with the replacement cell?

No, this is a fuel gauge calibration gap. The phone's coulomb counter was mapped to the discharge curve of the old, degraded cell — the new cell hits its voltage floor at a different point, so the OS percentage and actual cell state diverge. Run one full discharge from 100% down to automatic shutdown, then charge uninterrupted to 100% at standard rate. After that single cycle the fuel gauge IC recalibrates and the shutdowns stop.

The OS battery percentage jumps around erratically after I fitted the replacement — 60% one minute, 45% the next.

Erratic percentage readings happen because the fuel gauge IC is still using the old cell's charge curve as its reference. Until it collects enough data from the new cell, the reported state of charge will drift. Do not top up repeatedly in short bursts — that prevents the IC from completing a learning cycle. Let the phone discharge to automatic shutdown once, then charge straight to 100% without interruption. Stable readings typically follow within one to two full cycles.

Fast charging stopped working after I replaced the battery on my UTEC V566 — it only trickle charges now.

On the first cycle after a cell swap, the charge IC often falls back to standard current because the USB-PD or proprietary fast-charge handshake has not yet been confirmed against the new BMS. This is a safety behaviour, not a permanent fault. Let the phone complete one full charge-to-discharge cycle at the slower rate, then reconnect the fast charger. If fast charging still does not engage after that, check that the charging cable supports the protocol — a standard cable will never trigger fast charge regardless of the adapter.

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