Dell Latitude 14 5491 Replacement Battery 7.6V 8800mAh

Dell Latitude 14 5491 — 7.6V Li-ion Replacement Battery (GJKNX)

This 7.6V Li-ion battery replaces the original GJKNX cell in the Dell Latitude 14 5491 and Latitude 15 5591, along with the Latitude 5280 and 5290 series. Capacity is 8800mAh (66.88Wh) — matched to the OEM specification. It also covers additional Latitude business notebooks sharing the same connector, voltage rail, and BMS handshake.

• Latitude 5000-series compatibility: These models share a common 7.6V dual-cell architecture, identical 3-pin smart connector, and the same Dell EC firmware handshake. The BMS communicates battery identity via EEPROM, so the BIOS recognises this cell as it would the original.
• Bench tested on actual hardware: We ran this cell on a Latitude 5491 and cycled it through Dell's battery diagnostics via SupportAssist. The BMS reported correct voltage, current, and temperature readings across charge and discharge. No EC communication faults were logged.
• First-cycle calibration on Latitude hardware: After installing, run a full discharge to hibernate cutoff, then charge uninterrupted to 100% without using the laptop. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on Dell Latitude machines.

BIOS reporting battery health as poor immediately after replacement

The Latitude 5491 BIOS reads health data from the battery's EEPROM chip, not from live voltage readings. When a new cell is installed, that EEPROM starts at zero charge cycles, but the BIOS fuel gauge IC has not yet calibrated against the new cell's actual capacity curve. This mismatch triggers a false "poor health" warning in Dell SupportAssist and the BIOS battery page. One full discharge-to-hibernate followed by an uninterrupted charge to 100% completes the learn cycle and clears the flag.

Laptop shuts down at 20–30% charge shown on screen

This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. The new cell hits a voltage cliff at higher state-of-charge than the gauge predicts, so the system cuts power before the display reaches 0%. It is a calibration gap, not a cell fault. Run two full discharge-to-hibernate cycles with an uninterrupted recharge each time. After the second cycle, the gauge re-maps the curve and the cutoff point drops back to the correct level near 3.0V per cell.