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Rectangular black lithium-ion laptop battery with label showing 14.8V 40Wh 4-cell

FOCUSTEC

FOCUSTEC M5Y1K 40Wh 14.8V 4-cell laptop battery

SKU CH-1ZJF-T8V52

A 40 Wh, 14.8 V lithium-ion pack with four cells that replaces Dell part numbers including M5Y1K and P51F for Inspiron 14, 15 and 17 models

  • Battery TypeLithium-Ion
  • 40 Wh capacity keeps your laptop running longer
  • 8 V lithium‑ion chemistry provides stable power delivery
  • Four‑cell design fits the original battery bay exactly
  • Replaces Dell part numbers such as M5Y1K and P51F across many Inspiron models
  • Built‑in short‑circuit protection guards against electrical faults

40 Wh replacement battery for Dell Inspiron

This 40 Wh lithium-ion pack operates at 14.8 V and contains four cells. It replaces the Dell M5Y1K and numerous cross-reference part numbers such as P51F, VN3N0 and 451-BBMG. Compatible models include Inspiron 14, 15 and 17 series from the 3000 and 5000 families as well as selected Vostro 14 and 3558 units. Buyers needing a higher-capacity pack or a different voltage will not be served by this unit.

Thermals noise and power in daily use

Lithium-ion chemistry keeps self-discharge low and does not generate audible noise during operation. The pack delivers its rated 40 Wh without active cooling and draws power only when the laptop charges it. No fan or thermal solution is required because the battery itself produces negligible heat under normal loads.

Manual and protection circuitry included

The box contains one M5Y1K battery and a printed manual for installation guidance. Built-in protection guards against short circuits, over-charge and over-discharge as verified by the supplier’s intelligent detection tests. No additional software, drivers or mounting hardware are bundled.

Highlights

  • 40 Wh capacity keeps your laptop running longer
  • 8 V lithium‑ion chemistry provides stable power delivery
  • Four‑cell design fits the original battery bay exactly
  • Replaces Dell part numbers such as M5Y1K and P51F across many Inspiron models
  • Built‑in short‑circuit protection guards against electrical faults

Specifications

Battery TypeLithium-Ion

Questions about this item

How do I install the M5Y1K 14.8V battery in my Dell Inspiron 15 5000 series, and what step is often missed?

Power off the laptop, unplug the AC adapter, remove the bottom case screws, disconnect the old battery cable, fit the new 4-cell pack, reconnect the cable securely, then reassemble; the step often missed is reconnecting the battery cable before closing the case.

What maintenance or replacement will the 40Wh lithium-ion pack need later?

Lithium-ion cells degrade with charge cycles; expect reduced runtime after 300 to 500 full cycles, at which point the battery should be replaced with another 14.8V 40Wh unit.

What limit appears first during sustained use of this 2600mAh battery?

The 40Wh capacity sets the runtime ceiling; under continuous load the pack will reach its depth-of-discharge limit and shut down before thermal or voltage limits are hit.

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