Samsung Q25 1600 Battery SSB-Q20LS/C 7.4V 3800mAh Replacement

Samsung Q25 1600 Byron / Q20 / Q10 Series — 7.4V Li-ion Replacement Battery (SSB-Q20LS/C)

This is a 7.4V, 3800mAh Li-ion battery replacing OEM part SSB-Q20LS/C in the Samsung Q25 1600 Byron, Q25 TXC 1400, Q20, and Q10 TLC 933 series notebooks. It slots into the same bay and connects to the same charging circuit as the original Samsung cell. Capacity is 3800mAh (28.12Wh) — matched to product data, not estimated.

• Q-series notebook compatibility: The Q10, Q20, and Q25 lines share the same 7.4V two-cell Li-ion battery rail, identical connector pinout, and a common BMS communication protocol over the SMBus interface — which is why one cell covers all three platforms without modification.
• Bench tested on actual hardware: We ran this cell through the Samsung Q-series charge controller and confirmed the BMS handshake completes correctly, charge current transitions from CC to CV phase at the expected voltage, and no protection-trip error codes appear in the SMBus log during a full charge cycle.
• Post-install calibration on Q-series BIOS: After fitting this cell, run the laptop on battery power until it hibernates at low cutoff — do not interrupt it. 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 on this platform.

Why the Q25 BIOS flags a new battery as poor health immediately after installation

Samsung's Q-series BIOS reads battery health from EEPROM data stored on the original cell's fuel gauge IC. When you swap in a new cell, the BIOS compares the new cell's cycle count and rated capacity against the cached values from the old battery and flags a mismatch as poor health. This is not a fault with the replacement cell — it is a stale data problem. Running one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100% rewrites the BIOS battery learn table against the new cell's actual readings and clears the warning.

Laptop shuts off at 20–30% charge shown on the Q25

This happens when the fuel gauge IC has not yet calibrated to the new cell's voltage curve. The gauge IC maps remaining capacity to cell voltage using data from the old battery, so it misreads the voltage cliff on the new cell and triggers shutdown well above actual depletion. The fix is two to three full discharge and recharge cycles — this lets the fuel gauge IC rebuild its discharge curve against the new chemistry. After the third full cycle, the OS gauge should track accurately down to cutoff, which occurs at approximately 6.0V under load on this two-cell 7.4V pack.