ZTHY WY9DX 42Wh Laptop Battery for Dell Latitude

Replacement ZTHY WY9DX 42Wh (11.4V, 3500mAh) laptop battery designed to restore portable power for compatible Dell Latitude 14/15 5420/5520 and Precision 15 3560 models.

If your Dell laptop no longer holds a charge, the ZTHY WY9DX battery offers a direct-fit, Li-ion replacement that matches the original 3-cell form factor and voltage. This battery is engineered as a like-for-like alternative to factory units with compatible part numbers—helpful when the original pack fails or capacity has dropped. Before ordering, confirm the battery size and connector on your laptop to pick the correct model, since some laptops accept either a 42Wh (WY9DX) or a larger 63Wh (RJ40G) pack.

Which Dell models will this ZTHY WY9DX battery work with?

The WY9DX is compatible with a range of Latitude and Precision configurations that use the 42Wh 3-cell pack. It fits specific Latitude 14 5420 and Latitude 15 5520 variants as well as certain Precision 15 3560 builds and the P137G/P104F series listed by part number.

• Latitude 14 5420 variants (examples: CHKFM, FDTCY, XPC5H)
• Latitude 15 5520 variants (examples: 39V1H, FPKNM)
• Precision 15 3560 variants (models listed such as 3H45Y, 4MTF7, 758J7)
• Replaces part numbers like WY9DX, 1K2CF, 01K2CF, 075X16, 005R42, WK3F1, 0M3KCN

How do I confirm this battery fits my laptop?

Open your laptop’s rear cover and check the installed battery’s label for capacity and part number. The WY9DX is a 42Wh 3-cell Li-ion pack; if your machine originally uses a 63Wh 4-cell (RJ40G), this 42Wh unit will not match physical size or run time.

• Look for capacity marking: 42Wh or 11.4V on the existing battery
• Compare part numbers stamped on the original pack
• Check connector location and screw pattern for a physical fit

What should I do if the new battery isn’t recognized at first?

Occasionally systems need the battery to be seated and cycled to register correctly. Reinstall the battery, ensure the connector sits fully in the socket, then follow a simple charge/discharge routine to help the battery’s electronics initialize.

• Reseat the pack and double-check the connector engagement
• Discharge to about 10–20% (avoid 0%), then recharge fully
• Repeat charge/discharge 3–4 times to wake the battery’s reporting

What are the key technical details and precautions?

The WY9DX is a black, 3-cell lithium-ion battery rated at 11.4 volts and 3500mAh (42Wh). Handle with care during installation and avoid shorting contacts; use the battery only in listed compatible models and follow proper disposal rules for lithium batteries.

• Battery chemistry: Li-ion; voltage: 11.4V; capacity: 42Wh / 3500mAh
• Color: black; form: 3-cell internal replacement
• Do not puncture, incinerate, or expose to extreme heat

Who is this for: The ZTHY WY9DX battery is ideal for Dell Latitude and Precision owners whose original battery has lost capacity or failed, and who need an OEM-style replacement that preserves the laptop’s original fit and weight. It suits IT technicians performing repairs, students and professionals wanting reliable daily runtime, and anyone who has verified their machine accepts the 42Wh 3-cell variant rather than the larger 63Wh pack.