Sager 7358 Replacement Battery 14.8V 5200mAh Li-ion

Sager 7358 / NP7358 — 14.8V Li-ion Replacement Battery

This is a 14.8V, 5200mAh (76.96Wh) Li-ion battery for the Sager 7358 and NP7358 notebooks. It replaces the original cell when the factory battery degrades, fails to hold a charge, or no longer registers correctly with the system. Voltage and connector match the original pack specification.

• 7358 and NP7358 compatibility: Both model designations share the same chassis, battery bay, and 14.8V power rail. The connector pinout and BMS communication protocol are identical across the 7358 and NP7358 variants, so one cell fits both without modification.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on a Sager NP7358 unit. The BMS negotiated correctly on first insertion, the fuel gauge IC began tracking within the first full cycle, and no error flags were raised by the firmware during testing.
• First-cycle calibration on the 7358: After installing, run one full discharge down to hibernate-cutoff, then charge uninterrupted to 100%. This gives the BIOS battery learn cycle a clean baseline against the new cell and clears the inaccurate health warning that appears on the first boot after every cell swap.

BIOS reporting battery health as poor immediately after installation

The 7358 BIOS stores historical charge data in EEPROM tied to the previous cell. When a new battery is installed, the system compares incoming BMS data against that stored profile and flags a mismatch as poor health. This is not a fault with the replacement cell — it is a calibration state. Running one complete discharge-to-hibernate followed by a full uninterrupted charge gives the BIOS a fresh reference point. After one or two cycles, the health indicator resolves to normal.

Laptop shutting down at 20–30% charge remaining

This happens when the cell voltage drops sharply under the combined load of the CPU, GPU, and display — a voltage cliff the fuel gauge IC did not anticipate. The gauge was calibrated to the old cell's discharge curve, so the percentage reading is inaccurate for the first few cycles on a new pack. The BMS triggers a protective shutdown before the display reads zero. After two full calibration cycles, the fuel gauge IC maps the new cell's curve and the shutdowns stop. If they continue past three cycles, check that the charge reached a true 100% — some Sager BIOS builds cap charging at 80% by default.