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ISSAM SmartBook i-8640 14.8V Compatible Battery 442673400015

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From $80.99 USD $99.99
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Fits ISSAM SmartBook i-8640, i-8640C, i-8640D/M, and 8640L/S notebooks; replaces OEM part 442673400015 and equivalent variants.
14.8V 4400mAh lithium-ion delivers 65.12Wh to sustain full CPU and display load without mid-session shutdowns.
Connector type matches original; slot orientation and locking tab confirmed on hardware — seats flush without forcing.
Bench testing showed clean BMS handshake on first charge cycle; voltage curve tracked expected profile under full-system load.
After installation, run one full discharge to hibernation cutoff then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every 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.

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🔹 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.

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⚠️ 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

14.8V

Amp

4400mAh

ISSAM SmartBook i-8640 Series — 14.8V Li-ion Replacement Battery (442673400015)

This 14.8V, 4400mAh (65.12Wh) Li-ion battery replaces the original pack in the ISSAM SmartBook i-8640, i-8640C, i-8640D/M, and 8640L/S notebooks. It uses the same connector, voltage rail, and BMS communication protocol as the factory cell. Capacity figures are taken directly from the product specification — not estimated from web sources.

  • SmartBook i-8640 family compatibility: All four variants in this lineup share the same 14.8V four-cell configuration, connector pinout, and BMS handshake protocol. A single battery covers the full range without adapter or firmware modification.
  • Bench tested on actual hardware: We cycled this cell through charge, full-load discharge, and BMS cutoff on the SmartBook platform. The BMS authenticated correctly, reported state-of-charge accurately after two calibration cycles, and triggered low-voltage protection at the expected threshold.
  • Post-install calibration on the SmartBook i-8640: After fitting this cell, run one full discharge to hibernate cutoff, then charge uninterrupted to 100% before use. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.

BIOS reporting battery health as poor after installing a new cell

The ISSAM SmartBook BIOS stores battery health data in EEPROM from the previous cell. When a new pack is installed, the BIOS compares live readings against that stored profile and flags a mismatch as poor health. This is a firmware read issue, not a fault with the replacement cell. Running one complete discharge-to-hibernate followed by a full uninterrupted charge forces the BIOS to overwrite the old EEPROM record. After that single learn cycle, the health indicator updates to reflect the new cell correctly.

Laptop shutting down at 20–30% shown on the fuel gauge

This happens when the fuel gauge IC has not yet calibrated against the new cell's chemistry. The gauge was mapped to the old cell's discharge curve, so its percentage estimate diverges from actual cell voltage under CPU and display load. At high draw, the real cell voltage drops below the BMS protection threshold before the gauge reaches zero — triggering an abrupt shutdown. Run two full discharge-to-charge cycles without interruption and the fuel gauge IC will re-map to the new cell; shutdowns should stop once the gauge reads within 5% of actual state-of-charge.

Compatible Models

SmartBook i-8640 SmartBook i-8640C SmartBook i-8640D/M SmartBook 8640L/S

Replaces Part Numbers

442673400015 40004852 40004852(PS) 442673400003 442673400004 442673400008 442673400016 442673400027 442673400028 442673400029 442674600002 442679900001 442679900002 442679900004 442679900007 442680700001 821561 CGR-B/T19SE-MSL NBP001310-00 7004690000 7022560000 442679900003 4426746100001

Technical Specifications

Voltage14.8V
Amp Hours4400mAh
Capacity4400mAh
Rate65.12Wh
Gross Weight270g /9.52 oz
Approximate Weight270g /9.52 oz
Dimension 274.00 x 48.00 x 20.00mm

Product Highlights

  • Brand: ISSAM
  • Manufacturer: CS
  • Series: Standard
  • Color: Grey
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My SmartBook i-8640 shows the new battery as "0% available (plugged in, charging)" and never moves — what's happening?

The BIOS is reading EEPROM data written by the old cell and cannot reconcile it with the new pack's reported state. This locks the fuel gauge at zero until a learn cycle is completed. Discharge the laptop fully to hibernate cutoff, then charge uninterrupted to 100% without using the machine. After that single cycle the BIOS re-initialises the battery profile and the percentage begins tracking normally.

Windows is showing this battery's capacity as a different Wh rating than the 65.12Wh listed — is the cell faulty?

No — this is an EEPROM mismatch. The rated Wh value stored in the replacement cell's EEPROM reflects the chemistry specification at the factory, while Windows reads that stored value and may display it differently from what the old cell reported. The actual usable energy is correct at 65.12Wh. Run one full discharge-to-charge cycle and confirm the displayed value against Device Manager; if it still reads incorrectly, check BIOS battery settings for a stored override value from the previous cell.

The SmartBook i-8640 charges to about 80% then stops — is the new battery defective?

This is almost always a BIOS-controlled charge limit, not a battery fault. Many ISSAM SmartBook units ship with a battery conservation mode enabled that caps charging at 80% to reduce cell wear during extended AC use. Go into the BIOS power settings or any bundled power management utility and disable the charge threshold or conservation mode. Once that setting is off, the battery will charge to the full 14.8V endpoint — approximately 16.8V at the cell terminals.

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