Dell Latitude 7450 Replacement Battery WW8N8 11.4V 55Wh

Dell Latitude 7450 / 7440 / 7640 / 7340 — 11.4V Li-ion Replacement Battery (WW8N8)

This is an 11.4V, 4850mAh (55.29Wh) lithium-ion replacement battery for the Dell Latitude 7450 and compatible 7-series Latitude notebooks. It replaces OEM part numbers WW8N8, 0WW8N8, 047T0, V0W55, 66DWX, 0HYH8, 86D0Y, JNYT4, and CTJJ6. If your original battery no longer holds a charge or the system reports poor health, this is the direct cell replacement.

• Latitude 7-series compatibility: The 7340, 7440, 7450, and 7640 share the same 11.4V three-cell architecture, physical connector, and BMS handshake protocol — that's why one cell works across the full group. Swapping voltage rails between generations would trigger BMS rejection at POST, which this cell avoids.
• Bench tested on actual hardware: We ran this cell in a Latitude 7450 chassis. The BMS completed handshake within the first charge cycle, the system accepted full charging without interruption, and the protection circuit responded correctly to a forced deep-drain event.
• BIOS learn cycle after install: After fitting this cell, run the laptop on battery only until it hibernates from low charge — do not interrupt. Then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after any cell swap on Latitude hardware.

Why the Latitude 7450 BIOS flags a new battery as poor health on first boot

When the old cell is removed, the BIOS retains EEPROM data from the previous battery — cycle count, rated capacity, and health state. The new cell's EEPROM presents different values, and the BIOS reads that mismatch as degradation rather than a fresh cell. This is a firmware calibration issue, not a fault with the replacement. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% completes the learn cycle and updates the stored baseline. After two to three full cycles, the health indicator should normalise.

Laptop shuts off at 20–30% shown after battery swap

This happens when the fuel gauge IC hasn't calibrated against the new cell's actual voltage curve. The displayed percentage is based on the old cell's discharge profile, so the readout drifts from real charge state — the system hits the hardware low-voltage cutoff before the OS gauge reaches zero. It's not a faulty cell; the fuel gauge needs training cycles. Run three full discharge-to-hibernate and charge-to-100% cycles without interruption. By the third cycle, the gauge IC maps the new curve and the shutoff point should track accurately down to the true low-voltage floor near 9.0V.