Quanta TW8 11.1V Replacement Battery SQU-805 4400mAh
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Quanta TW8 11.1V Replacement Battery SQU-805 4400mAh - 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.
Quanta TW8 11.1V Replacement Battery SQU-805 4400mAh - is backordered and will ship as soon as it is back in stock.
Voltage
11.1V
Amp
4400mAh
Quanta TW8 / SW8 / DW8 Series — 11.1V Li-ion Replacement Battery (SQU-805)
This is an 11.1V, 4400mAh (48.84Wh) Li-ion battery for the Quanta TW8, SW8, DW8, and EAA-89 notebook series. It replaces OEM part numbers SQU-804, SQU-805, SQU-807, and SW8-3S4400-B1B1, among others. The cell slots into the same bay as the original and uses the same three-pin connector arrangement.
- TW8 / SW8 / DW8 platform compatibility: These models share a common 11.1V three-cell rail, the same physical bay dimensions, and the same BMS communication line. One replacement part covers all three variants without modification.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a TW8 platform. The BMS handshake completed correctly, charge acceptance reached the rated 4400mAh, and the protection circuit tripped at the expected low-voltage cutoff without false trips at partial discharge.
- Post-install calibration on the TW8: After fitting the new cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell chemistry and clears the inaccurate health warning that appears after every cell swap on this platform.
Why the TW8 shuts down at 20–30% shown on the fuel gauge
When a cell ages, its internal resistance rises. Under full CPU and display load, voltage drops faster than the fuel gauge IC can track. The cell hits the BMS low-voltage cutoff while the gauge still reads 20–30%. A new cell at 4400mAh has lower internal resistance, so voltage holds steadier under the same load. After two to three full calibration cycles, the fuel gauge IC re-learns the discharge curve and the early shutdowns stop.
BIOS reporting battery health as "poor" or "unknown" after swap
The BIOS reads health data stored in the battery's EEPROM, not from live cell measurements. That EEPROM carries wear data written by the old cell over its lifetime. A replacement cell ships with a fresh EEPROM, which the BIOS interprets as a mismatch and flags as poor or unknown. Running the battery learn cycle — full discharge to hibernate, then an uninterrupted charge to 100% — lets the BIOS rewrite its reference data against the new cell. Check BIOS battery status after the first complete cycle.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Quanta
- 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 Quanta TW8 shows the new battery at 0% and won't read it at all — is the EEPROM the problem?
Yes. The BIOS pulls health and state-of-charge data from the battery's EEPROM chip. When a fresh cell goes in, the EEPROM doesn't carry the charge history the BIOS expects, so it reports 0% or unknown rather than reading live voltage. Run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. That learn cycle forces the BIOS to rewrite its reference data and the gauge should read correctly within two cycles.
The TW8 fuel gauge is jumping around — showing 60%, then 45%, then back up — after fitting the replacement cell.
The fuel gauge IC calibrates itself against discharge data accumulated over many cycles. A brand-new cell has no history in the IC, so the first few readings are unstable as the algorithm tries to map the new cell's discharge curve. This is not a fault with the battery. Run two to three complete discharge-to-hibernate and full-charge cycles and the gauge stabilises. After the third cycle, readings should track within a few percent of actual capacity.
System information shows this battery as 41Wh but the product lists 48.84Wh — why does the Wh rating look wrong?
The Wh figure shown in system info comes from a value stored in the battery's EEPROM at manufacture, which can differ from the actual cell chemistry rating. The physical cells in this pack deliver 48.84Wh; the EEPROM-reported figure is a separate data field written by the OEM and does not affect how the battery charges or discharges. If you want to confirm actual capacity, use a battery diagnostic tool such as BatteryInfoView on Windows and check the "Full Charged Capacity" reading after one complete charge cycle.
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