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NoteBook Co. 6400at Replacement Battery 12V 3800mAh DR36

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From $89.99 USD $110.99
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Fits NoteBook Co. 6400at notebooks; replaces OEM part DR36 or DR36S battery packs.
12V, 3800mAh (45.6Wh) nickel-metal hydride chemistry delivers full system runtime on a single charge cycle.
Connector and locking tab match original DR36 housing; slides into battery bay without modification or adapter.
Bench testing shows stable voltage delivery under sustained CPU and display load; BMS handshake completes on first insertion.
After installation, discharge fully to system shutdown then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears false health warnings that appear after cell swap.
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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

12V

Amp

3800mAh

NoteBook Co. Co 6400at — 12V Ni-MH Replacement Battery (DR36)

This is a 12V, 3800mAh (45.6Wh) nickel-metal hydride replacement battery for the NoteBook Co. Co 6400at notebook computer. It replaces OEM part numbers DR36 and DR36S. The battery restores unplugged operation to Co 6400at systems where the original cell has degraded or failed entirely.

  • Co 6400at platform fit: The Co 6400at uses a 12V Ni-MH cell with a specific connector and charge-management handshake. Both DR36 and DR36S are direct part number matches for this platform — the voltage rail and BMS communication remain consistent across the revision.
  • Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Co 6400at system. The BMS accepted the cell without fault flags, and charge current ramped correctly through the Ni-MH delta-V cutoff termination at full capacity.
  • First-cycle conditioning on Ni-MH: After installing, run one full discharge to the hibernate cutoff, then charge uninterrupted to 100%. Ni-MH cells in laptops require this to reset the BIOS battery learn cycle — skipping it leaves the fuel gauge reporting inaccurate state-of-charge data for the life of the cell.

BIOS reporting poor battery health immediately after swapping the Co 6400at cell

The Co 6400at BIOS reads health data from EEPROM values stored during the original cell's service life. When a new cell is installed, those stored values no longer match the actual cell state, so the BIOS flags the battery as degraded or unknown. This is not a fault with the replacement cell. Running a full discharge-to-hibernate followed by an uninterrupted charge to 100% triggers the battery learn cycle and overwrites the stale EEPROM data. After one or two full cycles, the health status clears.

Co 6400at shutting down unexpectedly while the OS gauge still shows 20–30%

This happens when the fuel gauge IC has not yet calibrated against the new Ni-MH cell's actual discharge curve. The IC uses an older reference curve and misjudges how much charge remains — the real voltage cliff arrives before the displayed percentage reaches zero. Under combined CPU and display load, the cell voltage drops faster than the fuel gauge tracks. Run two full discharge-to-hibernate and charge-to-100% cycles to let the IC recalibrate, then verify the resting voltage at full charge reads at or above 12V.

Compatible Models

Co 6400at

Replaces Part Numbers

DR36 DR36S

Technical Specifications

Voltage12V
Amp Hours3800mAh
Capacity3800mAh
Rate45.6Wh
Gross Weight150g /5.29 oz
Approximate Weight150g /5.29 oz
Dimension 139.50 x 89.00 x 20.00mm

Product Highlights

  • Brand: NoteBook Co.
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Ni-MH
  • Battery Type: Ni-MH
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My Co 6400at BIOS still shows the battery as "unknown" or 0% after fitting the new DR36 cell — what's wrong?

The BIOS is reading EEPROM data written by the original cell, and the new cell hasn't yet built a matching charge history. Run a full discharge to the hibernate cutoff, then charge uninterrupted to 100% without interruption. This triggers the battery learn cycle and overwrites the stale EEPROM values. After one complete cycle, the BIOS should resolve the unknown status.

System info on my Co 6400at is showing the wrong Wh rating for the replacement battery — is the cell faulty?

It's not a fault. The Wh figure displayed in system info is pulled from the EEPROM of the old cell or from a firmware default, not measured live from the new cell. The DR36 replacement is rated at 45.6Wh by the product data, and that capacity is correct. The displayed figure will update after the BIOS completes a full battery learn cycle — run one full discharge-to-hibernate and uninterrupted charge-to-100% to push the correct data through.

The Co 6400at fuel gauge reading jumps around wildly for the first few charge cycles after the swap — is the DR36 cell defective?

The fuel gauge IC is still calibrating against the new Ni-MH discharge curve. Ni-MH cells have a flatter discharge profile than what the IC may have stored from the degraded original, so the percentage estimate drifts until it has enough real-world data. Run two complete discharge-to-hibernate and charge-to-100% cycles without interruption. By the third cycle, the gauge IC will have recalibrated and the readings will stabilise.

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