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Black rectangular lithium-ion laptop battery with label showing 42Wh 11.4V

Beisite

Beisite WY9DX 42Wh 11.4V laptop battery for Dell Latitude 5420 5520

SKU CH-3EYC-XEEXT

42Wh 11.4V lithium-ion replacement battery for Dell Latitude 5420 and 5520 models

  • Battery typeLithium-Ion
  • Product colorBlack
  • Product typeBattery
  • 42 Wh capacity powers Dell Latitude 5420 and 5520
  • 4 V lithium-ion cell matches original voltage specification
  • Replaces part numbers WY9DX, 0WK3F1, 005R42, 31CP5/57/78
  • Brand-new condition ensures full cycle life from first charge
  • 12-month warranty backs reliable daily operation

Replacement battery for Latitude 5420 and 5520

This 11.4 V lithium-ion pack replaces part numbers WY9DX, 0WK3F1, 005R42 and 31CP5/57/78. It is built for Dell Latitude 5420 and 5520 models and ships as a single unit in black. The pack is brand new and carries a 12-month warranty.

Capacity and voltage define runtime

The cell delivers 42 Wh at 11.4 V, which sets the energy available for each charge cycle. Runtime will vary with workload, screen brightness and power settings, so the same capacity can give different results on different days. No higher-capacity version is offered in this listing.

Match the part number before ordering

Compatibility is limited to the exact part numbers and laptop models listed above. Buyers who need a battery for any other Dell series or a different voltage should not use this pack. Always confirm the original part number on the old battery before purchase.

How it compares

Measured against everything we stock in Laptop Chargers & Batteries, at today’s prices. Recalculated every night.

Price $33.99
Pricier than about 60% of the 27,790 comparable items (median $30.99).

Specifications

Product
Brand nameWY9DX
Model nameWY9DX
Product colorBlack
Product typeBattery
Power
Battery typeLithium-Ion

Questions about this item

How do I confirm this 42Wh 11.4V battery is the right replacement for my Latitude?

Match the part numbers on your old battery — WY9DX, 0WK3F1, 005R42 or 31CP5/57/78 — and verify your laptop is a Latitude 5420 or 5520; this pack is built for those models only.

What does the 42Wh rating actually deliver in daily use on a Latitude 5420 or 5520?

The 42 watt-hour capacity restores the original runtime Dell specified for these models; real-world hours depend on screen brightness, workload and power-profile settings you choose in Windows.

Does the 11.4V lithium-ion pack use a standard Dell connector so it fits without adapters?

Yes — the battery is engineered to the exact voltage and connector layout Dell uses for the Latitude 5420 and 5520, so it slots straight into the battery bay with no extra cables or brackets.

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