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Rectangular black lithium-ion laptop battery with three cells and label showing 44Wh 11.4V

E-buy

E-buy 45N1742 44Wh 11.4V 3-cell laptop battery

SKU CH-G500-CQVRM

Replacement 44Wh 11.4V 3-cell Li-ion battery for ThinkPad T550, T560, W550s and P50s

  • Battery typeLithium-Ion
  • 44Wh capacity restores original runtime for ThinkPad T550, T560, W550s and P50s
  • 4V 3-cell lithium-ion design matches factory voltage and cell layout
  • Replaces Lenovo part numbers 45N1740, 45N1741, 45N1742, 45N1743, SB10K12721 and 00NY639
  • Built-in protection circuits guard against overcharging and overheating
  • 100% brand-new unit supplied direct from the manufacturer with a 1-year warranty

Direct Replacement Battery

The E-buy 45N1742 is a 44Wh lithium-ion battery built for Lenovo ThinkPad T550, T560, W550s and P50s laptops. It operates at 11.4V across three cells and delivers 3900mAh capacity. This unit suits professionals who need to restore original runtime on compatible business machines.

Replaces Original Part Numbers

This battery replaces Lenovo part numbers 45N1740, 45N1741, 45N1742, 45N1743 plus SB10K12721 and 00NY639. The swap is worth it when the original pack no longer holds a full charge or shows reduced runtime. It is not for users whose laptop model falls outside the listed ThinkPad series.

Sustained Operation Behaviour

Built-in safety protections guard against overcharging and overheating during extended work sessions. The lithium-ion chemistry maintains stable voltage output across the discharge cycle. The pack is brand new from the manufacturer and carries a one-year warranty.

How it compares

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

Price $23.99
Cheaper than about 64% of the 27,790 comparable items (median $30.99).

Specifications

Power
Battery typeLithium-Ion

Questions about this item

What internal bay does the 45N1742 battery occupy in a ThinkPad T550?

The 3-cell 44Wh pack slides into the standard internal battery compartment used by the T550, T560, W550s and P50s models.

Which screw or latch step is most often missed when fitting the 11.4V replacement?

After inserting the pack, the bottom-case captive screws must be re-tightened to lock the battery rail; skipping this leaves the pack loose.

When should the 3900mAh Li-ion unit be swapped for a fresh one?

Replace it once runtime drops well below the original 44Wh capacity or the pack no longer holds a full charge.

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