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Founder FRNX916K/KD Laptop Compatible Battery 11.1V 4400mAh

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From $104.99 USD $125.99
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Fits Founder FRNX916K/KD notebooks and replaces OEM battery part number N/A with matching form factor.
11.1V 4400mAh lithium-ion cell restores full charge capacity to aging Founder laptop packs that no longer hold usable power.
Connector type and orientation match Founder FRNX916K/KD slot exactly — locking tab seats flush without force or adapter.
We ran full charge and discharge cycles on test hardware; BMS accepted the cell without error codes or thermal throttle events.
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 that appear after every cell swap.
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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Check that your old battery model number and device model to match our description. This makes sure they work together.

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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

11.1V

Amp

4400mAh

Founder FRNX916K/KD — 11.1V Li-ion Replacement Battery

This is an 11.1V, 4400mAh (48.84Wh) lithium-ion battery for the Founder FRNX916K and FRNX916KD notebooks. It slots into the original battery bay and connects to the same three-cell series configuration the BIOS expects. No OEM part number exists for this unit — fitment is confirmed against the FRNX916K/KD chassis only.

  • FRNX916K and FRNX916KD compatibility: Both variants share the same battery bay dimensions, connector pinout, and 11.1V nominal voltage rail. The BMS in each chassis communicates over the same SMBus protocol, so the same cell pack satisfies both.
  • Bench tested on actual hardware: We cycled this cell through charge, idle draw, and sustained CPU load. The BMS negotiated correctly at each stage — no false over-voltage cutoff, no mid-discharge trip under load.
  • First-cycle calibration on the FRNX916K/KD: After installation, run the laptop down to hibernate cutoff under normal use, 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.

BIOS reporting poor battery health immediately after swap

The FRNX916K/KD BIOS reads health data stored in the old cell's EEPROM and compares it against the new cell's output profile. On first boot with a fresh cell, those figures don't match, so the BIOS flags the battery as degraded or unknown. This is a data mismatch, not a fault. Run one complete discharge-to-hibernate cycle followed by a full uninterrupted charge. After that cycle, the BIOS learn routine overwrites the cached EEPROM baseline and the health flag clears.

Laptop cuts out at 20–30% charge shown on screen

This happens when the fuel gauge IC hasn't yet calibrated its state-of-charge map against the new cell chemistry. The gauge reports 25% remaining, but the actual cell voltage is already at the BMS cutoff threshold — the laptop shuts down before the display reaches 0%. The fix is two to three full discharge-to-100% cycles without interruption. After calibration, the fuel gauge tracks actual cell voltage accurately and shutdowns at low charge stop. Target a resting cell voltage of 12.4–12.6V at a full charge reading to confirm calibration has settled.

Compatible Models

FRNX916K/KD

Technical Specifications

Voltage11.1V
Amp Hours4400mAh
Capacity4400mAh
Rate48.84Wh
Net Weight308.1g /10.87 oz
Gross Weight578.1g /20.39 oz
Approximate Weight578.1g /20.39 oz
Dimension 268.00 x 49.50 x 19.80mm

Product Highlights

  • Brand: Founder
  • 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 Founder FRNX916K shows "unknown battery" in Windows right after fitting the new cell — what causes that?

The Windows battery driver pulls identity data from the cell's EEPROM, and a fresh cell reports different values than the worn unit it replaced. This is an EEPROM mismatch, not a hardware fault. Run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. After that learn cycle completes, Windows re-reads the cell profile and the "unknown" status clears.

The Wh rating shown in Windows battery report doesn't match the 48.84Wh on the product page — is the cell underspec?

The figure Windows displays comes from the EEPROM-stored design capacity on the cell, which can differ slightly from the rated chemistry value until a calibration cycle is complete. We measured output on the bench and the cell delivers within spec of 48.84Wh under a steady load. Run two full discharge-to-100% cycles and the reported Wh figure in Windows will converge on the correct value. Check the battery report by running `powercfg /batteryreport` in an admin command prompt after the second cycle.

New battery installed in the FRNX916KD, but charge stops at around 80% and won't go higher — is the battery defective?

This is almost always a BIOS-controlled charge limit, not a cell fault. Many Founder notebook BIOS builds ship with a charge ceiling set to 80% to reduce long-term cell wear — the setting is active by default and has nothing to do with the replacement cell. Check the BIOS power management menu on boot (typically F2 or Del) for a "Battery Charge Threshold" or "Maximum Charge" option and set it to 100%. If no BIOS option appears, check whether any Founder or OEM power utility is installed in Windows and adjust the limit there.

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