About this replacement
Acer Aspire S7-392 — 7.5V Li-Polymer Replacement Battery (AP13F3N)
This is a 7.5V, 6250mAh (46.88Wh) lithium-polymer replacement battery for the Acer Aspire S7-392 ultrabook. It fits the full S7-392 range, including the S7-392-54208g12tws, S7-392-54208g25tws, and S7-392-9890 variants. OEM part number AP13F3N confirms compatibility across these models.
- S7-392 platform fit: Every S7-392 variant runs the same 7.5V two-cell Li-Polymer configuration with a shared connector and BMS handshake protocol. The AP13F3N is the single battery spec across all S7-392 sub-models, so voltage rail and connector pin-out are consistent across the lineup.
- Bench tested on actual hardware: We ran this cell on an S7-392 chassis and confirmed BMS handshake, charge acceptance from 0% to 100%, and correct Wh reporting in Acer's power management interface. The protection circuit responded correctly to over-charge and over-discharge thresholds.
- Post-install calibration for the S7-392: After fitting this cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears in Windows after every cell swap on this platform.
Why the S7-392 reports poor battery health immediately after a cell swap
The S7-392 BIOS stores charge cycle count and health data in EEPROM on the original battery's protection board. When a new cell is installed, the BIOS reads unfamiliar EEPROM values and flags the battery as degraded or unknown. This is a firmware read mismatch, not a fault with the replacement cell. Running the battery learn cycle — full discharge to hibernate then uninterrupted charge to 100% — lets the BIOS recalibrate against the new cell's actual chemistry and clears the warning.
S7-392 shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's voltage curve. The IC maps percentage to voltage using data from the old, degraded cell, so it misjudges where the new cell's cutoff actually sits. Under combined CPU and display load, the laptop hits the real voltage floor before the displayed percentage reaches zero. Run two complete discharge-to-hibernate and full-charge cycles — after that, the fuel gauge IC re-anchors to the new cell and the shutdowns stop. Confirm the cell is holding above 7.2V under load before ruling out a BMS issue.