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Uniwill U40 14.4V Replacement Battery U40-3S4400-G1L3

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Fits Uniwill U40 notebook; replaces OEM part numbers U40-3S4400-G1L3, U40-3S4400-C1M1, U40-3S4400-C1H1, U40-3S4000-G1B1, U40-3S4400-S1G1, U40-3S4000-S1S1, 63GU40026-1A, and 63GU40023-3A.
14.4V 2200mAh lithium-ion cell delivers 31.68Wh; matches original output for full CPU and display runtime without voltage sag.
Connector type matches Uniwill U40 slot orientation; locking tab seats flush against frame with no forcing required.
We bench-tested discharge curve and BMS handshake on a U40 unit; cell accepted BIOS communication on first insertion and held voltage under sustained load.
After installation, fully discharge the pack to hibernation cutoff, then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears incorrect health warnings that appear after every cell swap.
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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

14.4V

Amp

2200mAh

Uniwill U40 — 14.4V Li-ion Replacement Battery (U40-3S4400-G1L3)

This is a 14.4V, 2200mAh (31.68Wh) lithium-ion battery for the Uniwill U40 notebook. It replaces OEM part numbers U40-3S4400-G1L3, U40-3S4400-C1M1, U40-3S4400-C1H1, U40-3S4000-G1B1, U40-3S4400-S1G1, U40-3S4000-S1S1, 63GU40026-1A, and 63GU40023-3A. Correct fit for U40 units that no longer hold charge or fail to power on without AC connected.

  • U40 platform compatibility: All listed OEM part numbers share the same 14.4V three-cell series configuration and connector pinout on the U40 mainboard. The BMS handshake protocol is identical across these variants, so the BIOS accepts this cell without a firmware flag.
  • Bench tested on actual hardware: We cycled this battery through charge, full-load discharge, and BMS cutoff on a U40 unit. The protection circuit tripped cleanly at low-cell threshold and resumed charging without a reset sequence.
  • First-cycle calibration on the U40: After installing, run one full discharge until the laptop hibernates, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap on this platform.

BIOS reporting battery health as poor immediately after fitting a new cell

The U40 BIOS stores charge history and health data from the previous cell in its battery learn registers. When a new cell goes in, that stale EEPROM data makes the BIOS flag the replacement as degraded — even when the cell is brand new. This is not a fault with the battery. Run one full discharge to hibernate-cutoff, then a full uninterrupted charge to 100%. After that cycle, the BIOS relearns the cell and the health warning clears.

U40 shutting down abruptly at 20–30% charge shown on screen

The fuel gauge IC calibrates its state-of-charge curve against the old cell's impedance profile. With a new cell installed, the reported percentage and actual cell voltage diverge at the lower end of the curve. Under combined CPU and display load, the cell voltage drops below the BMS cutoff threshold before the OS gauge reaches 0% — so the laptop cuts out while the screen still shows 20–30%. Two to three full discharge-and-charge cycles recalibrate the fuel gauge IC against the new cell's actual voltage curve. After calibration, the shutdown will align with the gauge reading near 5%.

Compatible Models

U40

Replaces Part Numbers

U40-3S4400-G1L3 U40-3S4400-C1M1 U40-3S4400-C1H1 U40-3S4000-G1B1 U40-3S4400-S1G1 U40-3S4000-S1S1 63GU40026-1A 63GU40023-3A

Technical Specifications

Voltage14.4V
Amp Hours2200mAh
Capacity2200mAh
Rate31.68Wh
Gross Weight100g /3.53 oz
Approximate Weight100g /3.53 oz

Product Highlights

  • Brand: Uniwill
  • 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

The Uniwill U40 BIOS shows 0% or "unknown" right after I fitted the new battery — is the cell dead?

It is not dead. The BIOS holds EEPROM data from the old cell and has not yet learned the new one's profile. Run the laptop on battery until it hibernates from low charge, then plug in and let it charge to 100% without interruption. That single learn cycle clears the 0% or unknown reading from the BIOS health register.

My U40 shows 31Wh in Windows battery report but the system info screen shows a different number — which is correct?

The figure in system info pulls from the EEPROM rated value written at manufacture, which can differ from the actual chemistry spec of a replacement cell. The 31.68Wh figure stamped on this battery is the accurate rated capacity. Windows will update its reported value after one or two full calibration cycles once the fuel gauge IC has mapped the new cell's discharge curve.

The replacement battery charges fine but the U40's fuel gauge reads wildly different percentages each time — 60% one boot, 85% the next.

The fuel gauge IC on the U40 mainboard tracks charge state against a learned discharge curve built from the previous cell. A new cell has different internal resistance characteristics, so the IC's reference points are off. Run three complete cycles — full discharge to hibernate, then full charge to 100% each time. By the third cycle the fuel gauge IC has enough data to anchor its curve to the new cell and the readings stabilise.

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