About this replacement
Dell Studio 1535 / 1555 Series — 11.4V Li-ion Replacement Battery (312-0701)
This is an 11.4V, 4400mAh (50.16Wh) Li-ion replacement battery for the Dell Studio 1535, 1536, 1537, and 1555 laptops. It replaces OEM part numbers 312-0701, KM958, KM965, MT264, WU946, and several other Dell-issued part codes covering this platform. When the original cell degrades and the laptop stops holding a charge, this cell restores untethered operation.
- Studio 1535 / 1536 / 1537 / 1555 platform fit: These four models share the same battery bay geometry, connector pinout, and BMS communication protocol. Dell sourced multiple OEM part numbers across production runs — KM958, MT264, WU946, RM803, and others — but they all draw from the same 11.4V cell configuration with identical SMBus handshake logic.
- Bench tested on actual hardware: We ran this cell on a Studio 1535 and confirmed the BMS initialised correctly, the BIOS recognised the battery without error flags, and charge acceptance proceeded through all stages to 100% without the controller halting the cycle early.
- Post-install calibration on the Studio 1535: After fitting this cell, run the laptop on battery until it hibernates at low-charge cutoff, then charge uninterrupted to 100%. This single discharge-charge cycle resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.
Why the Studio 1535 BIOS reports poor battery health after a cell swap
The Studio 1535 stores battery health data in the EEPROM of the original cell. When a new cell goes in, that EEPROM contains no accumulated charge history, so the BIOS reads it as degraded or unknown. This is a data mismatch, not a fault with the replacement cell. Running one full discharge-to-hibernate followed by a complete uninterrupted charge gives the BIOS enough cycle data to recalculate health accurately. After that single calibration pass, the health warning clears.
Laptop shuts down at 20–30% charge shown on the meter
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The gauge is still using the old cell's discharge profile, so it underestimates remaining capacity and triggers a low-voltage shutdown earlier than it should. The fix is the same calibration cycle: discharge fully to hibernate cutoff, then charge to 100% without interruption. After two to three full cycles, the fuel gauge IC locks onto the new cell's curve and the shutdowns stop. Confirm the cell is reading above 11.0V at the point the shutdown occurs — if it is, the gauge is the issue, not the cell.