Asus W3 Replacement Battery 14.8V 4400mAh Li-ion A42-W3
This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.
WECARE5
Check that your old battery model number and device model to match our description. This makes sure they work together.
We ship your order same day if you buy it before 4 PM EST.
Asus W3 Replacement Battery 14.8V 4400mAh Li-ion A42-W3 - is backordered and will ship as soon as it is back in stock.
Let customers speak for us
Send Your Battery Photo
Expert Technician Help
Snap a photo or video of your battery and send it to us. We'll identify the exact replacement—fast and hassle-free. Our team has helped thousands of customers find the right battery quickly and easily.
POST YOUR BATTERY IMAGE
Product & Solutions Expert
✉ sales@batteryweb.com
Battery Care Tips
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
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
⚠️ 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.
Asus W3 Replacement Battery 14.8V 4400mAh Li-ion A42-W3 - is backordered and will ship as soon as it is back in stock.
Voltage
14.8V
Amp
4400mAh
Asus W3 Series — 14.8V Li-ion Replacement Battery (A42-W3)
This is a 14.8V, 4400mAh (65.12Wh) Li-ion replacement battery for the Asus W3 notebook laptop. It fits the W3, W3A, W3N, and W3V model lines. OEM part numbers A42-W3, 90-NCB1B2000, 70-NCB1B1001M, and 90-NCB1B3000 all cross to this cell.
- W3 series compatibility: The W3, W3A, W3N, and W3V all run the same 14.8V four-cell battery rail with an identical connector and BMS handshake. One cell fits the entire platform because Asus held the same charge controller and pack geometry across these variants.
- Bench tested on actual hardware: We cycled this pack through full charge and discharge on the W3 platform. The BMS communicated correctly with the charge controller, accepted a full charge to 16.8V at the cell level, and triggered thermal cutoff within spec under load.
- First-cycle reset on W3 notebooks: After installing this battery, run one full discharge until the laptop hibernates at cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the false health warning that appears after every pack swap on this platform.
BIOS reporting poor battery health immediately after replacing the W3 pack
The Asus W3 BIOS reads health data from EEPROM stored on the old battery pack. When a new cell is installed, that EEPROM data is gone and the BIOS flags the battery as degraded or unknown. This is not a fault with the replacement cell. Running one complete discharge-to-hibernate followed by a full uninterrupted charge resets the learn cycle. After one to two full cycles, the BIOS health indicator clears and reports accurately.
W3 shutting down at 20–30% charge shown on the fuel gauge
The fuel gauge IC on the W3 platform calibrates its low-voltage cutoff estimate against charge history from the previous cell. With a new pack installed, those historical readings do not match the actual voltage curve of the replacement cell. Under combined CPU and display load, the pack hits a voltage cliff the gauge did not predict, and the system shuts off before the displayed percentage reaches zero. Run two to three full discharge and charge cycles to let the fuel gauge IC recalibrate against the new cell. After calibration, the cutoff should align to approximately 10.5V at the pack level.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Asus
- Manufacturer: CS
- Series: Standard
- Color: Metallic Grey
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My Asus W3 shows the battery as "unknown" or 0% right after I put in a new cell — is the battery dead?
No. The W3 BIOS reads capacity and health data from EEPROM on the original pack. When that pack is removed, the stored data is gone and the system reports "unknown" or 0% until a new learn cycle runs. Discharge the laptop fully until it hibernates, then charge uninterrupted to 100%. One complete cycle is usually enough to clear the unknown status.
The fuel gauge on my W3 reads wildly different percentages each time I unplug — jumps from 60% to 15% in minutes.
The fuel gauge IC on the W3 calibrates its percentage readings against charge and discharge history from the previous cell. A new cell has a different voltage curve, so the IC's estimates are inaccurate for the first few cycles. Run three full discharge-to-hibernate and charge-to-100% cycles without interruption. After those calibration cycles the gauge tracks the actual cell voltage correctly and the erratic jumps stop.
My W3 system info shows the wrong Wh rating after replacing the battery — it says something like 48Wh but the new pack is 65.12Wh.
The Wh figure shown in Windows or the BIOS comes from the EEPROM data written by the original factory pack, not from measuring the new cell directly. Until the BIOS learn cycle completes, it displays the old pack's rated figure. Run a full discharge to hibernate followed by a complete uninterrupted charge. After one full cycle the system recalculates the Wh rating against actual cell data and the figure updates to reflect the 65.12Wh capacity of this replacement.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
