Dell Latitude 7410 WY9MP Replacement Battery 11.4V 5500mAh

Dell Latitude 7410 — 11.4V Li-Polymer Replacement Battery (WY9MP)

This is an 11.4V, 5500mAh (62.7Wh) Li-Polymer battery for the Dell Latitude 7410 ultrabook. It replaces OEM part numbers WY9MP, XMV7T, Y7HR3, 35J09, 7YX5Y, and YJ9RP. The Latitude 7410 uses a slim Li-Polymer pack seated flush against the lower chassis — physical fit and connector orientation match the original.

• Latitude 7410 fitment: The 7410 shares its battery connector and BMS handshake protocol across both the standard and 2-in-1 chassis variants. The BMS in this pack communicates over the SMBus lines the 7410's EC expects — the system will read voltage, state of charge, and cycle count without throwing an unknown device flag on first boot.
• Bench tested on actual hardware: We ran this pack on a Latitude 7410 and confirmed the EC accepted the cell, charge initiated at the correct CV/CC profile, and the BMS protection circuit tripped correctly at over-discharge threshold. Charge terminated cleanly at 100% without the truncated charge event some third-party packs trigger.
• First-cycle calibration on the 7410: After installing, discharge the laptop fully until it hibernates on its own, then charge uninterrupted to 100% without using the machine. This forces the fuel gauge IC to map its charge curve against the new cell and clears the inaccurate battery health warning the BIOS throws after every cell replacement.

BIOS reporting poor battery health immediately after fitting a new cell

The Latitude 7410's EC reads battery health from EEPROM data written during the charge learn cycle — not from the physical cell voltage alone. When you swap the pack, the EC compares the new cell's reported state against a learned baseline that no longer exists, so it flags the battery as degraded. This is not a fault with the replacement cell. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100%, and the EC will rewrite its baseline. After one complete cycle, the health warning clears.

Laptop shuts down at 20–30% charge shown on a new battery

This happens because the fuel gauge IC is still using the charge curve from the old, degraded cell to estimate remaining capacity on the new one. The new cell's voltage-to-capacity curve is steeper and sits higher — the gauge reads 25% but the cell is already at its low-voltage cliff under CPU and display load. The fix is calibration, not a hardware fault. Run two full discharge-to-hibernate and full recharge cycles, and the gauge IC will remap its curve to match the new cell's actual voltage profile. After the second cycle, shutdowns at false percentages stop.