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Rectangular black lithium-polymer laptop battery, 37Wh 7.5V

POWER-FENG

POWER-FENG 37Wh C21N1408 Battery for Asus Vivobook 4000 MX555 V555L V5555LB V555

SKU CH-PAFJ-Z21DM

A 37 Wh lithium-polymer replacement battery at 7.5 V fits Asus Vivobook 4000, MX555, V555L and related models

  • TypeBattery
  • Battery TypeLaptop Batteries
  • 37 Wh capacity delivers extended runtime
  • 5 V output matches original specifications
  • Li-polymer chemistry provides stable discharge
  • 4829 mAh rating supports long sessions
  • Compatible with Vivobook 4000 and V555 series

Compatible Asus Vivobook Replacement Battery

This new POWER-FENG lithium-polymer battery replaces part number C21N1408 in several Asus Vivobook models. It fits the 4000 series, MX555, V555L, V555U, V555LB, V5555LB, A555U, X555U, X555UA, X555UQ and K555U notebooks. The unit arrives in black and is ready to install.

Suits owners restoring listed Vivobook laptops.

This battery suits owners who need a direct replacement for the exact part numbers and laptop models listed above. It is not for users whose device requires a different voltage, capacity or connector layout. Buyers with unlisted Asus series or other brands should verify their original part number before ordering.

37Wh 7.5V capacity determines runtime and fit

The battery delivers a capacity of 37Wh (4829mAh) at 7.5V, which defines the available runtime and physical compatibility for the supported Vivobook chassis. Matching these two figures to the original specification is the single check that confirms the part will operate correctly in the listed models.

Highlights

  • 37 Wh capacity delivers extended runtime
  • 5 V output matches original specifications
  • Li-polymer chemistry provides stable discharge
  • 4829 mAh rating supports long sessions
  • Compatible with Vivobook 4000 and V555 series

Specifications

TypeBattery
Battery TypeLaptop Batteries

Questions about this item

How is the 7.5V 37Wh Li-polymer battery installed in a Vivobook 4000, and what step is often missed?

Power off the laptop, disconnect the AC adapter, remove the base screws, detach the old battery connector from the motherboard, fit the new C21N1408 pack, reconnect the cable firmly, replace the base, then charge fully before first use.

What maintenance or replacement will the C21N1408 battery need over its life?

No scheduled maintenance is required; the Li-polymer cells gradually lose capacity, so plan to replace the pack when runtime drops below your needs — typically after several hundred full charge cycles.

What limit appears first during sustained use of this 4829mAh pack?

The 37Wh capacity sets the runtime ceiling; under continuous load the pack will deplete before any thermal or voltage limit is reached, so expect operating time to match the watt-hour rating.

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