We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Black rectangular lithium-ion laptop battery with six cells

FOCUSTEC

FOCUSTEC MR90Y 65WH 11.1V 6-cell laptop battery

SKU CH-TBB1-SEC0K

65 Wh 11.1 V lithium-ion 6-cell replacement battery for Dell Inspiron 15 and 17 models including 3521, 3543, 5537, 5721 and 17-3721 series

  • Battery TypeLithium-Ion
  • 65 Wh capacity powers extended work sessions
  • 1 V lithium-ion chemistry matches original specifications
  • Six-cell design balances runtime with slim fit
  • UL, CE, FCC and RoHS certifications confirm safety standards
  • Overcharge, overdischarge, over-temperature and short-circuit protection built in

65 Wh replacement battery for Dell Inspiron

This 11.1 V lithium-ion pack delivers 65 Wh across six cells and matches the original MR90Y form factor. It is built for owners of listed Inspiron 15 and 17 models who need a direct drop-in replacement. The black casing aligns with the factory aesthetic and installs without tools. Safety certifications include UL, CE, FCC and RoHS compliance.

Suits owners of compatible Dell Inspiron notebooks

Buyers whose laptop part number appears in the supported MR90Y, 0MF69, 49VTP or 312-1390 lists can install this unit immediately. Users with different Dell series or non-Dell brands should look elsewhere because the connector and dimensions are model-specific. The battery is not intended for systems requiring a higher or lower voltage pack.

11.1 V 65 Wh capacity defines runtime

The 65 Wh rating at 11.1 V determines how long the notebook runs on a single charge. Cells are rated for up to 1000 recharge cycles over the service life. Overcharge, overdischarge, over-temperature and short-circuit protection circuits are integrated. No other specification governs compatibility as closely as the voltage and capacity match.

Highlights

  • 65 Wh capacity powers extended work sessions
  • 1 V lithium-ion chemistry matches original specifications
  • Six-cell design balances runtime with slim fit
  • UL, CE, FCC and RoHS certifications confirm safety standards
  • Overcharge, overdischarge, over-temperature and short-circuit protection built in

Specifications

Battery TypeLithium-Ion

Questions about this item

How many recharge cycles can the 6-cell Li-ion pack deliver before it needs replacement?

The battery is rated for up to 1000 recharge cycles over its lifespan.

What is the first limit reached during continuous operation — voltage drop or thermal protection?

Over-temperature protection activates before voltage sag becomes an issue.

Does the 11.1V 65WH unit run hot or draw extra power when the laptop is used all day?

Built-in over-temperature and short-circuit protection keep heat and power draw within safe limits.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.