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Kennex 420 Laptop Compatible Battery 11.1V 4400mAh

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From $104.99 USD $125.99
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Fits Kennex 420, 321, 327, and 328 notebooks; replaces OEM battery for these models.
11.1V, 4400mAh delivers 48.84Wh — sustains full CPU and display load across work sessions.
Connector type and orientation match original slot; locking tab engages flush with chassis frame.
We bench-tested this cell against the Kennex platform; BMS accepted handshake on first insertion without fault codes.
After installation, discharge fully to hibernation cutoff then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears inaccurate health warnings that appear after cell swaps.
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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.

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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.

Voltage

11.1V

Amp

4400mAh

Kennex 420 / 321 / 327 / 328 — 11.1V Li-ion Replacement Battery

This is an 11.1V, 4400mAh (48.84Wh) Li-ion battery for the Kennex 420, 321, 327, and 328 notebook series. It replaces the original cell when capacity has degraded or the pack no longer holds a charge. Dimensions are 136.27 x 72.20 x 20.09mm — confirm your original pack matches before installing.

  • 420 / 321 / 327 / 328 series compatibility: These four Kennex models share the same 11.1V battery bay, connector pinout, and BMS communication protocol. One cell fits all four without modification.
  • Bench tested on actual hardware: We cycled this cell through charge and discharge on a Kennex 420 unit. The BMS handshake completed correctly, charge current stepped down at 95% as expected, and the protection circuit tripped cleanly at low-voltage cutoff.
  • First-cycle calibration on Kennex notebooks: After installing, 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 a cell swap.

BIOS reporting battery health as poor after replacement

The Kennex BIOS stores charge history and health data from the previous cell in its battery learn table. When a new cell goes in, that stored data no longer matches the actual chemistry, so the BIOS flags the battery as degraded or unknown. This is a data mismatch, not a fault with the replacement cell. Run two full discharge-to-hibernate and uninterrupted charge cycles — the BIOS relearns the cell and the health warning clears.

Laptop shuts down with 20–30% still showing on the gauge

The fuel gauge IC on Kennex notebooks maps percentage readings against voltage curves calibrated to the original cell. After a swap, that map is stale, so the gauge reads 25% while the actual cell voltage has already hit the BMS low-voltage cutoff threshold — typically around 9.0V for a 3S Li-ion pack. The system shuts down because the cell can no longer sustain voltage under combined CPU and display load, even though the gauge hasn't caught up. Complete two full discharge-to-100% charge cycles to let the fuel gauge IC recalibrate against the new cell's actual voltage curve.

Compatible Models

420 321 327 328

Technical Specifications

Voltage11.1V
Amp Hours4400mAh
Capacity4400mAh
Rate48.84Wh
Net Weight305.2g /10.77 oz
Gross Weight455.2g /16.06 oz
Approximate Weight455.2g /16.06 oz
Dimension 136.27 x 72.20 x 20.09mm

Product Highlights

  • Brand: Kennex
  • 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 Kennex 420 shows the new battery as "0%" or "unknown" in Windows — is the cell dead?

No. The fuel gauge IC is reading EEPROM data written by the old cell, which doesn't match the new chemistry. Windows reports 0% or unknown until the IC recalibrates. Fully discharge the laptop to hibernate-cutoff, then charge uninterrupted to 100% — repeat this cycle twice and the gauge will map correctly to the new cell.

The battery icon shows a different Wh rating in system info than what's on the product listing — why?

The Wh value shown in system info is pulled from the EEPROM on the battery's BMS, which stores the manufacturer's rated capacity for that cell group. If the EEPROM value differs slightly from the listed 48.84Wh, it's a rounding or rating-method difference between the cell manufacturer and the system firmware — not a sign the cell is wrong or underspec. Check actual charge behaviour over two full cycles rather than relying on the EEPROM-reported figure.

Charging stops at around 80% and won't go higher — is the replacement cell faulty?

This is almost always a BIOS-controlled charge limit, not a cell fault. Many Kennex notebooks ship with a battery health or conservation mode enabled in the BIOS or OEM power utility that caps charging at 80% to reduce long-term wear. Go into BIOS settings or the Kennex power management software and disable the charge limit or switch to "full charge" mode — charging should then proceed normally to 100%.

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