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Asus A31-K56 Replacement Battery 14.4V 2200mAh Li-ion

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From $66.99 USD $82.99
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Fits Asus A46, A56, K46, K56 Ultrabook models; replaces A31-K56, A32-K56, A41-K56, A42-K56 OEM batteries.
14.4V 2200mAh Li-ion cell delivers 31.68Wh to restore full charge cycles on these thin ultrabooks.
Connector slides straight into the battery slot with locking tab securing against the chassis housing.
We bench-tested this cell in an A46 — BMS accepted the pack on first insertion, voltage held steady under sustained load.
After installation, run one full discharge to hibernate-cutoff then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears inaccurate health warnings.
Extended delivery time

Available by SPECIAL ORDER. Delivery for this product typically takes 2 weeks.

Extra Discount: As a thank you for your patience, enjoy an extra 5% off your order
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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

Asus A46 / K56 Ultrabook Series — 14.4V Li-ion Replacement Battery (A31-K56 / A32-K56)

This 14.4V Li-ion battery replaces the original cell in the Asus A46, A56, K46, and K56 Ultrabook series. It carries a capacity of 2200mAh (31.68Wh) and matches the OEM part numbers A31-K56, A32-K56, A41-K56, and A42-K56. Connector pinout and BMS communication protocol match the original specification.

  • A46 / A56 / K46 / K56 platform fit: These four Ultrabook lines share the same battery bay dimensions, 14.4V rail, and multi-pin BMS handshake connector. One cell fits all four because Asus used a common power board across this chassis generation.
  • Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a K56 unit. The BMS communicated charge state correctly to the EC, held cutoff voltage within spec, and showed no thermal anomalies during the charge phase.
  • Post-install calibration on the K56 EC: After fitting this cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after swapping cells on this platform.

BIOS reporting poor battery health immediately after fitting a new cell

The Asus K56 EC reads health data from EEPROM stored on the outgoing cell. When a new cell goes in, that EEPROM data is blank or mismatched, so the BIOS flags poor health before any charge cycle runs. This is not a fault with the replacement cell — it is a firmware artefact. Run one full discharge to hibernate-cutoff, then a full uninterrupted charge to 100%. After that learn cycle completes, the EC writes fresh calibration data and the health warning clears.

Laptop shuts down hard at 20–30% charge shown on screen

This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The displayed percentage no longer matches the real cell voltage, so the system hits the low-voltage cutoff while the gauge still shows reserve capacity. It is not a defective cell — it is a calibration lag. Force two or three complete discharge-to-hibernate and full-charge cycles back-to-back, and the gauge will track accurately. After the third cycle, the shutdown point should align with a displayed level below 5%.

Compatible Models

A46 Ultrabook A56 Ultrabook K46 Ultrabook K56 Ultrabook S40 Ultrabook S405 Ultrabook S46 Ultrabook S505 Ultrabook S56 Ultrabook A46C A46CA A46CM A56C A56CA A56CM K46C K46CA K46CM K56C K56CA K56CM S40C S40CA S40CM S405C S405CA S405CM S46C S46CA S46CM S505C S505CA S505CM S56C S56CA S56CM A46E A46SV A46SV-WX039D A46CA-WX043D A46CM-WX085V A46CM-WX095D A56E K46CA-WX013 K46CA-WX014 K46CA-WX015 K46CM-WX002D K46CM-WX003D K46CM-WX004D K46CM-WX007 K46CM-1AWX K46CM-WX025V K46CM-WX047V K46CM-WX090V K56CM-XX055D K56CM-XX014D K56CM-XX014 K56CM-XX055 K56CM-XX008 S56CM-XX046R S405CM-WX117H S505CM-XX188H S505CM-XX189P S46CA-WX016 S46CA-WX017R S46CA-WX017H S46CA-WX021R S46CA-WX044R S46CM-WX023V S46CM-WX046V S46CM-WX049D S46CM-WX053R S46CM-WX124H S56CA-XX011D S56CA-XX015D S56CA-XX019D S56CA-XX011V S56CA-XX011H S56CA-XX030R S56CA-XX056R S56CM-XX3317S S56CM-XX017V S56CM-XX018V S56CM-XX032D S56CM-XX034X S56CM-XX035X S56CM-XX035V S56CM-XX069D S56CM-XX070D S56CM-XX072V S56CM-XX079V S56CM-XX08?5H S56CM-XX140

Replaces Part Numbers

A31-K56 A32-K56 A41-K56 A42-K56

Technical Specifications

Voltage14.4V
Amp Hours2200mAh
Capacity2200mAh
Rate31.68Wh
Net Weight224g /7.90 oz
Gross Weight494g /17.43 oz
Approximate Weight494g /17.43 oz
Dimension 285.30 x 35.50 x 21.80mm

Product Highlights

  • Brand: Asus
  • 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 Asus K56 shows the battery as "unknown" or 0% right after I installed the new cell — what's wrong?

The EC pulled identity and state-of-charge data from the old cell's EEPROM, and the new cell has no matching data written yet. The system reports unknown because it has nothing to read — not because the cell is faulty. Plug in the charger, let the cell charge fully to 100% uninterrupted, then run it down to hibernate-cutoff once. After that first complete cycle, the EC registers the new cell correctly and the 0% or unknown reading clears.

Windows is showing a wildly different Wh rating for this battery than the original — is the cell wrong?

The Wh figure Windows displays comes from EEPROM data embedded in the cell, which reflects the rated chemistry specification rather than the measured capacity of your specific unit. A small difference between the displayed Wh and the original is normal when switching between cell batches. If the figure shown is 31–32Wh, that matches this cell's 31.68Wh spec and the reading is correct. No action is needed unless the value shown is dramatically outside that range.

The new battery stops charging at around 80% and won't go higher — is the cell defective?

The Asus K56 BIOS includes a battery charge limit setting that caps charging at 80% to reduce long-term cell stress. This setting survives a cell swap because it lives in firmware, not in the battery. Open MyASUS or the ASUS Battery Health Charging utility, check the charge mode setting, and switch it from "Balanced" or "Maximum Lifespan" to "Full Capacity." The cell will then charge to 100%.

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