Asus FX504 Replacement Battery B31N1726 11.4V 4100mAh
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Asus FX504 Replacement Battery B31N1726 11.4V 4100mAh - is backordered and will ship as soon as it is back in stock.
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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 FX504 Replacement Battery B31N1726 11.4V 4100mAh - is backordered and will ship as soon as it is back in stock.
Voltage
11.4V
Amp
4100mAh
Asus FX504 Series — 11.4V Li-ion Replacement Battery (B31N1726)
This is a 11.4V 4100mAh (46.74Wh) Li-ion battery for the Asus FX504 gaming laptop line, including the FX504G, FX504GE, and related variants. It replaces OEM part B31N1726 and fits the same physical bay with the original connector orientation. Voltage and cell count match the stock specification exactly.
- FX504 platform compatibility: The FX504, FX504G, and FX504GE all share the same battery bay dimensions, 3-cell 11.4V rail, and EC connector pinout. One cell replaces all three variants without modification.
- Bench tested on actual hardware: We cycled this cell on an FX504GE under sustained CPU and GPU load. The BMS held charge cutoff at 12.6V and low-voltage protection tripped correctly before cell damage could occur.
- First-cycle calibration on the FX504: After installing, run one full discharge until the laptop hibernates, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the false health warning the EC logs after every cell swap.
BIOS reporting poor battery health immediately after swap
The FX504's embedded controller reads health data from the battery's EEPROM, which still carries the degraded metrics written by the old cell. The new cell hasn't yet written its own charge cycles to that register. One full discharge-to-hibernate followed by a complete uninterrupted charge gives the EC enough data to overwrite the stale EEPROM values. After that cycle, the BIOS health status clears on its own — no software tool needed.
Laptop shuts down at 20–30% charge shown on screen
This is a fuel gauge IC calibration fault, not a cell defect. The gauge IC was calibrated against the old degraded cell and its voltage-to-capacity curve no longer maps accurately to the new chemistry. Under heavy CPU and GPU load, the new cell delivers strong current but the gauge misreads the voltage slope and fires a shutdown before the actual cutoff. Run two full discharge-to-hibernate cycles back-to-back and the IC recalibrates its internal curve. The shutdown threshold should stabilise below 5% after the second cycle.
Compatible Models
Replaces Part Numbers
Technical Specifications
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 FX504 shows the new battery as "0% available (plugged in, not charging)" right after install — what's wrong?
The EC hasn't recognised the new cell yet because the EEPROM state from the old battery is still active in firmware. Shut the laptop down completely, unplug AC, hold the power button for 10 seconds to drain residual charge from the board, then reconnect AC and power on. If the gauge still reads 0%, run the BIOS battery learn cycle — one full discharge to hibernate, then an uninterrupted charge to 100%.
Windows says the battery Wh rating is different from what I ordered — is the cell wrong?
It isn't. The Wh figure Windows reports is pulled from the EEPROM on the battery PCB, which stores the manufacturer's rated capacity under controlled lab conditions. That number will differ slightly from the 46.74Wh in the listing because EEPROM values reflect chemistry tolerances at cell manufacture, not real-world measured output. The physical cell is correct — check that the voltage reads 11.4V in a battery reporting tool like BatteryInfoView to confirm.
The FX504 charges fine but the percentage jumps around — reads 67%, then 54%, then back to 71% without changing load — is the cell defective?
The fuel gauge IC is still running its calibration map against the old cell's degraded curve. It has no accurate reference points for the new cell's voltage slope yet. Run two complete discharge-to-hibernate cycles with no interruptions and no partial top-ups in between. After the second full cycle, the IC rebuilds its curve against the new cell and the gauge stabilises.
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