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Asus UX30KU Replacement Battery 11.1V 3250mAh C31-UX30

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From $76.99 USD $94.99
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Fits Asus UX30KU, UX30, and UX30KA ultrabooks; replaces C31-UX30, 70-NVS1B1000Z, and PP625289AB-3250.
11.1V, 3250mAh lithium-polymer cell delivers 36.08Wh for full-day unplugged operation on this ultraportable.
Connector type matches OEM slot orientation; physical dimensions 174.55 x 0.57 x 7.38mm seat flush without modification.
Bench testing showed BMS accepted charge at standard laptop rates; no fault codes or cutoff anomalies observed during full discharge cycles.
After installation, run one full discharge to hibernation shutdown, then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears incorrect health warnings.
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.

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⚠️ 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

11.1V

Amp

3250mAh

Asus UX30KU / UX30 Series — 11.1V Li-Polymer Replacement Battery (C31-UX30)

This is an 11.1V, 3250mAh (36.08Wh) lithium-polymer replacement battery for the Asus UX30KU ultrabook and the broader UX30 family, including the UX30, UX30KA, and UX30-a1. It uses OEM part numbers C31-UX30, 70-NVS1B1000Z, and PP625289AB-3250. The cell slots into the same bay and connects to the same BMS circuitry as the original.

  • UX30 family compatibility: The UX30, UX30KU, UX30KA, and UX30-a1 all share the same 11.1V three-cell Li-Polymer pack architecture, the same physical connector, and the same BMS handshake protocol — so one cell services the entire line without modification.
  • Bench tested on actual hardware: We ran this cell through charge and discharge cycles on UX30-series hardware. The BMS accepted the pack, communicated state-of-charge correctly to the OS, and held voltage across load without tripping the protection circuit.
  • First-cycle recalibration on the UX30KU: After fitting this battery, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This forces the BIOS to complete its battery learn cycle against the new cell and clears the inaccurate health warning that appears after every cell swap on this platform.

Why the UX30KU BIOS flags poor battery health after a cell swap

The UX30KU stores battery state data — cycle count, charge history, and health rating — in EEPROM on the old cell's fuel gauge IC. When you fit a new pack, the BIOS reads stale EEPROM data and reports poor health even though the cell is fresh. This is not a fault with the replacement. Running the full discharge-to-hibernate then uninterrupted charge cycle forces the BIOS learn algorithm to overwrite that stale data with real readings from the new cell. After one or two complete cycles, the health flag clears and the fuel gauge reads accurately.

UX30KU shutting down at 20–30% charge remaining

This happens when the cell voltage drops below the BMS cutoff threshold under full CPU and display load — even though the OS gauge still shows charge remaining. The fuel gauge IC has not yet calibrated against the new cell's actual voltage curve, so the percentage shown does not match the real state of charge. The fix is the same recalibration cycle: discharge fully to hibernate, then charge to 100% without interruption. After two complete cycles the gauge aligns to the cell and the early shutdown stops.

Compatible Models

UX30KU UX30 UX30KA UX30-a1 UX30-qx005c UX30-qx007e UX30-qx011e UX30-qx015c UX30-qx087x UX30s UX30s-su35neggaw UX30-1A UX30-QX011C UX30-QX054V UX30-QX062R UX30-QX084C UX30-QX078X UX30-1B UX30-QX031C UX30-QX054X UX30-QX079V UX30-QX115C UX30-2A UX30-QX036C UX30-QX062C UX30-QX082X

Replaces Part Numbers

C31-UX30 70-NVS1B1000Z PP625289AB-3250

Technical Specifications

Voltage11.1V
Amp Hours3250mAh
Capacity3250mAh
Rate36.08Wh
Net Weight227.3g /8.02 oz
Gross Weight367.3g /12.96 oz
Approximate Weight367.3g /12.96 oz
Dimension 174.55 x 0.57 x 7.38mm

Product Highlights

  • Brand: Asus
  • 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

The UX30KU BIOS says the battery health is poor right after I fitted the new cell — is it faulty?

It is not faulty. The BIOS reads health data from EEPROM stored on the old cell's fuel gauge IC, and that stale data carries over after a swap. Run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. That forces the BIOS learn cycle to write fresh data from the new cell and the poor health flag clears.

Windows is showing a completely different Wh rating for this battery than what is listed — why?

The Wh figure Windows reports comes from the EEPROM on the fuel gauge IC, which stores the original factory-rated capacity of the old cell. The new cell's actual chemistry data has not yet been written to that register. After one or two full discharge-and-charge calibration cycles, the reported Wh value updates to reflect the new cell and the mismatch disappears.

The fuel gauge on my UX30KU jumps around wildly for the first few days — is the replacement cell bad?

The fuel gauge IC needs several full cycles to build an accurate model of the new cell's voltage curve. Until that calibration is complete, the percentage reading can swing by 15–20 points under varying loads. Run two complete discharge-to-hibernate then full-charge cycles without interruption. By the third cycle the gauge stabilises and tracks accurately under normal use.

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