About this replacement
Toshiba Dynabook Satellite B450/B Series — 10.8V Li-ion Replacement Battery (PA3788U-1BRS)
This is a 10.8V, 4400mAh (47.52Wh) lithium-ion battery for the Toshiba Dynabook Satellite B450/B and related B-series business notebooks. It cross-references OEM part numbers PA3788U-1BRS, PABAS223, PA3787U-1BRS, and PABAS221. The physical dimensions are 206.90 × 45.00 × 20.10mm — confirm your bay size before ordering.
- B450/B, B452/F, B550/B, B551/E shared platform: These Dynabook B-series models run the same 10.8V battery rail, use an identical multi-pin connector, and share the same BMS handshake protocol — which is why one part number covers the full range.
- Bench tested on actual hardware: We ran this cell through charge and discharge on a B-series unit. The BMS initialised correctly, reported cell voltage within expected range, and the protection circuit tripped cleanly at low-voltage cutoff without false-positive shutdowns.
- Post-install calibration on Dynabook B-series: After fitting, run one full discharge down to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that frequently appears after a cell swap on these models.
BIOS reporting poor battery health after replacement on Dynabook B-series
The Dynabook B450/B BIOS reads health data stored in the battery's EEPROM. When a new cell is installed, the EEPROM data doesn't match the BIOS's learned history from the old pack, so it flags the battery as degraded or unknown. This is a calibration state, not a hardware fault. One complete discharge-to-hibernate followed by an uninterrupted full charge gives the BIOS enough data to re-learn the new cell and clear the warning.
Laptop shuts down abruptly at 20–30% charge shown on screen
This happens when the fuel gauge IC hasn't been calibrated against the new cell yet. The gauge miscalculates remaining capacity, and the laptop cuts power before the true low-voltage threshold is reached. It's not a faulty battery — it's the IC working from stale reference data. Run two full discharge-to-hibernate and full recharge cycles, then verify the laptop reaches shutdown no earlier than 5–7% indicated charge.