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What Battery Does a Lenovo ThinkPad T440 Take?

Lenovo ThinkPad T440

Hardware reports identify 2 battery slots for this model. These are the part numbers observed for each slot.

Rear battery

Part numbers

  • 45N1775 — seen in 27 reports
  • 45N1127 — seen in 17 reports
  • 45N1736 — seen in 5 reports
  • 45N1734 — seen in 3 reports
  • 45N1735 — seen in 3 reports
  • 45N1738 — seen in 2 reports
  • 45N1767 — seen in 2 reports
  • 45N1125 — seen in 1 report

Reports for this model and slot contain multiple part numbers. The reports do not establish that those parts are interchangeable.

Manufacturer
SANYO, LGC, SMP
Capacities observed
23.2 Wh, 23.5 Wh, 47.5 Wh, 71.1 Wh
Voltage
11.10 V
Chemistry
Li-ion

Reports for this model and slot contain multiple capacities. Match the specifications on your existing battery and verify any change with the manufacturer.

Based on 62 reports.

Front battery

Part numbers

  • 45N1773 — seen in 29 reports
  • 45N1111 — seen in 25 reports

Reports for this model and slot contain multiple part numbers. The reports do not establish that those parts are interchangeable.

Manufacturer
SANYO, SONY, Batt Manufacture
Capacity
23.2 Wh
Voltage
11.10 V
Chemistry
Li-ion

Based on 55 reports.

Based on 62 independent hardware reports for the Lenovo ThinkPad T440.

Before you order, verify the replacement:
  • Match the exact part number printed on your current battery, or confirm a different number in the manufacturer’s service manual.
  • Check voltage, connector, polarity, dimensions, and mounting points against the original battery.
  • Make sure the seller names your exact laptop model or variant and offers a suitable return policy.

A part number appearing in these reports is an observation, not a guarantee that it fits every unit sold under the same model name.

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How we know

This answer is derived from 62 independent hardware reports for the Lenovo ThinkPad T440, of which 100% agree. We publish a model only when the reports agree overwhelmingly.

Check it yourself

On Windows, open a terminal and run powercfg /batteryreport, then open the generated HTML report — it names the battery’s model and part number. On Linux, run upower -i /org/freedesktop/UPower/devices/battery_BAT0. On any laptop, the surest method is the label printed on the battery itself, visible once you remove the back panel.

Other laptops reporting the same battery part number

These field reports contain an exact matching part number at the same observed voltage. That is useful evidence, but it does not guarantee the connector, dimensions, mounting points, firmware, or physical fit.

Browse all Lenovo battery records →

Battery health and replacement signs

Short runtime, unexpected shutdowns, or a large drop from design capacity can justify a closer check; a charging fault does not by itself prove the battery is worn out. See how to check battery health, judge replacement signs, or diagnose a charging problem.

Lenovo ThinkPad T440 battery questions

What battery part number was reported for the Lenovo ThinkPad T440?

Hardware reports contain “45N1775”, “45N1127”, “45N1736”, “45N1734”, “45N1735”, “45N1738”, “45N1767”, “45N1125”, “45N1773”, “45N1111”. Confirm the printed identifier and physical specifications on your installed battery before ordering.

What battery capacity was observed?

The reports contain 23.2 Wh, 23.5 Wh, 47.5 Wh, 71.1 Wh. Multiple values can reflect variants or replacements, so match your own label rather than choosing capacity alone.

Does a matching part number guarantee fit?

No. Verify the exact laptop variant, voltage, connector, dimensions, mounting points, and manufacturer or seller documentation as well.

More Lenovo laptops

All Lenovo models →

Battery part numbers derived from linuxhw/DMI, licensed CC-BY-4.0.