About this replacement
Toshiba Satellite M30-S3501 — 10.8V Li-ion Replacement Battery (PA3331U-1BAS)
This is a 10.8V, 8800mAh Li-ion battery for the Toshiba Satellite M30 series laptop. It replaces OEM part numbers PA3331U-1BAS, PA3331U-1BRS, PA3332U-1BAS, and PA3332U-1BRS. Fit models include the Satellite M30-S3501, M30-241, M30-S309, M30-154, and over 70 additional M30 variants.
- M30 series platform compatibility: These M30 variants share a common power rail at 10.8V and use the same physical connector and BMS handshake protocol. Swapping between PA3331 and PA3332 suffix part numbers is safe — Toshiba revised the part number mid-production without changing the electrical spec.
- Bench tested on actual hardware: We ran this cell on an M30-series chassis and monitored the BMS through charge and discharge cycles. The protection circuit tripped correctly at low-voltage cutoff and accepted a full charge without thermal event or BIOS rejection.
- Post-install calibration on the M30: After fitting this battery, run the laptop on battery only until it reaches hibernate cutoff — do not interrupt with AC. Then charge uninterrupted to 100%. This resets the M30's BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after fitting a new cell
The Satellite M30 BIOS stores battery health data in EEPROM tied to the original cell's charge history. When a new cell is installed, that stored data no longer matches the actual cell, so the BIOS flags it as degraded. This is not a fault with the replacement — it is stale data from the old battery. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% forces the BIOS to rewrite its battery profile. After that single learn cycle, the health warning clears.
Laptop shuts down abruptly at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The OS reads 25% remaining, but the cell hits its low-voltage cliff under full CPU and display load before the gauge catches up. The shutdown is the BMS protecting the cell — not a defect. Run two full discharge-to-hibernate cycles without interruption, and the fuel gauge IC re-maps the curve accurately against the new cell chemistry. After calibration, cutoff aligns with the displayed percentage at approximately 10.8V nominal load.