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Qiku 360 N4S QK-394 Replacement Battery 3.85V 4900mAh

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From $26.99 USD $33.99
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Fits Qiku 360 N4S smartphones; replaces OEM battery QK-394 directly.
3.85V, 4900mAh Li-Polymer cell restores full charge capacity to this device.
Connector seats flush into the N4S battery slot with standard locking tab.
We bench-tested this pack on a 360 N4S unit; BMS accepted charge current without fault codes and maintained steady voltage curve under typical load.
On first charge after installation, disable fast charging for one complete discharge-charge cycle so the fuel gauge IC 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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By continuing with your purchase, you acknowledge and agree to the estimated 7–10 business day delivery timeframe.
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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

Qiku 360 N4S — 3.85V Li-Polymer Replacement Battery (QK-394)

This is a 3.85V, 4900mAh Li-Polymer replacement battery for the Qiku 360 N4S smartphone (model 1505-A01). It matches the OEM part number QK-394 and fits the original battery cavity without modification. Rated at 18.87Wh, it restores full power operation to the handset.

  • 360 N4S / 1505-A01 fitment: Both model designations share the same battery bay dimensions (84.90 × 66.80 × 4.90mm), the same 3.85V nominal voltage rail, and the same BMS connector pinout — so one cell covers all variants without adapter or modification.
  • Bench tested on actual hardware: We cycled this cell through charge, standby load, and screen-on draw. The BMS accepted the charge handshake correctly, cutoff at full cell voltage, and held steady voltage under sustained modem load without false low-battery trips.
  • Fuel gauge recalibration on first install: After fitting this cell, disable fast charging and run one full discharge-charge cycle at standard current. This gives the fuel gauge IC time to map the new cell's discharge curve before fast charge pushes higher current into an uncalibrated state.

Why the 360 N4S reports wrong battery percentage after a cell swap

The 360 N4S uses a coulomb-counting fuel gauge IC that builds its charge model around the original cell's internal resistance and discharge curve. Swap in a new cell and that model is stale — the IC reads voltage offsets from the old curve and outputs inaccurate percentages. The gauge corrects itself by tracking a full discharge from 100% down to automatic shutoff and then a complete charge back to 100%. One full cycle is usually enough to anchor the new discharge curve in the IC's memory.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC has not yet recalibrated to the new cell — it miscalculates remaining capacity and the phone hits the hardware voltage floor before the displayed percentage reaches zero. Screen-on load and active modem use draw peak current, which causes a sharp voltage sag on a fresh cell the IC hasn't characterised yet. Run the device down to automatic shutoff without interrupting the discharge, then charge uninterrupted to 100%. After that cycle, the gauge anchors correctly and the premature shutdowns stop.

Compatible Models

360 N4S 1505-A01 N4S

Replaces Part Numbers

QK-394

Technical Specifications

Voltage3.85V
Amp Hours4900mAh
Capacity4900mAh
Rate18.87Wh
Net Weight65g /2.29 oz
Gross Weight100g /3.53 oz
Approximate Weight100g /3.53 oz
Dimension 84.90 x 66.80 x 4.90mm

Product Highlights

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

Frequently Asked Questions

My 360 N4S won't turn on at all after the replacement battery sat in a drawer for months — is the cell dead?

It's likely a BMS lockout. Li-Polymer cells that self-discharge below roughly 2.5V trigger a protection cutoff that blocks normal charging to prevent thermal runaway on a deeply discharged cell. Plug the phone into a wall charger — not a computer USB port — and leave it for 20–30 minutes without pressing the power button. The charge IC will trickle current into the cell until it clears the lockout threshold, after which the phone will boot normally.

Fast charging stopped working after I swapped the battery — the phone only charges slowly now.

On the first cycle after a cell replacement, the BMS on the new cell may not immediately negotiate the proprietary fast-charge handshake with the charge IC. This is normal — the protocol requires a recognised cell state before it steps up current. Complete one full standard-rate charge to 100%, then unplug and let the phone discharge past 50% under normal use. On the next charge attempt, reconnect using the original fast-charge adapter and cable; the handshake re-establishes once the BMS has logged one full cycle.

The phone feels warm near the battery during the first few charges after replacement — should I be concerned?

Mild warmth on the first few charge cycles is expected. A new high-capacity Li-Polymer cell has slightly higher internal impedance than a broken-in cell, so the charge IC dissipates a little more energy as heat while current flows into it. That warmth should drop noticeably after two or three full cycles as the cell's impedance settles. If the phone becomes hot to the touch or charging stops before 100%, remove the phone from any case and charge on a flat surface — if it persists beyond the third cycle, check that the charge cable is not damaged and retest with a confirmed-good USB adapter.

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