Dell Latitude E5289 Replacement Battery 7.6V 7750mAh 6CYH6

Dell Latitude E5289 / N003L7390-C-D1606FTCN — 7.6V Li-Polymer Replacement Battery (6CYH6)

This is a 7.6V, 7750mAh (58.9Wh) lithium-polymer replacement battery for the Dell Latitude E5289, N003L7390-C-D1606FTCN, N012L7390-C-D1706FTCN, Latitude L3180, and related models. It replaces OEM part numbers 6CYH6, 725KY, K5XWW, and N18GG. The cell physically seats into the standard internal bay and connects to Dell's battery management circuit via the stock multi-pin connector.

• Latitude 5289 / 7390 series compatibility: These models share a common 7.6V power rail, identical bay dimensions (253.70 × 114.12 × 4.90mm), and the same BMS handshake protocol — which is why one part number covers all of them. The BIOS reads authentication data from the EEPROM on the battery's protection board, not from the cell chemistry directly.
• Bench tested on actual hardware: We ran this cell on a Latitude 7390 chassis. The BMS accepted the handshake without fault codes, charge initiation started within 30 seconds of connection, and the protection circuit tripped correctly at the low-voltage cutoff threshold during a controlled discharge cycle.
• First-cycle calibration on Dell systems: After installing this battery, run one full discharge down to hibernate cutoff, then charge uninterrupted to 100%. This forces the fuel gauge IC to map its capacity estimates against the new cell and clears the inaccurate health warning that appears in Dell Power Manager after every cell swap.

BIOS reporting battery health as poor immediately after installation

Dell's BIOS reads a health value stored in the battery's EEPROM — not a live reading from the cell itself. When a new cell is installed, that EEPROM value hasn't been updated by a learn cycle yet, so the BIOS displays "poor" or "replace battery" even on a brand-new unit. Running a single full discharge-to-hibernate followed by an uninterrupted charge to 100% resets the learn cycle. After one or two complete cycles, Power Manager and the BIOS health readout align with actual cell capacity.

Laptop shuts down at 20–30% charge shown on the gauge

This happens when the fuel gauge IC hasn't been calibrated to the new cell's discharge curve. The old curve maps to the previous cell's voltage profile — so when the new cell hits a voltage cliff around 7.0V under combined CPU and display load, the system shuts down while the gauge still shows charge remaining. It is not a cell fault. Run two full calibration cycles: discharge to hibernate cutoff, recharge to 100% without interruption. After the second cycle, the gauge tracks the actual voltage curve and the early shutdowns stop.