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Lenovo ThinkPad T440P 45N1144 Replacement Battery 11.1V 4400mAh

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From $109.99 USD $130.99
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Fits Lenovo ThinkPad T440P, T540P, L440, L540 and replaces OEM part numbers 45N1144, 45N1148, 45N1150, 45N1158, 45N1160, and related Lenovo battery SKUs.
Delivers 11.1V at 4400mAh capacity for standard business computing without power outlet access.
Connector slides into the battery bay slot with a locking tab that secures flush against the chassis.
We bench tested this cell on a T440P motherboard; the BMS initialized cleanly on first charge with no fault codes.
After installation, run one full discharge to hibernation cutoff then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.
Delivery time

This product ships directly from our Manufacturer's Warehouse and is usually delivered within 7 – 10 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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Fresh Battery, Worth the Wait

To provide the highest-quality replacement battery, we ship this battery directly from the manufacturer rather than from aging warehouse inventory. This means delivery may take a little longer, but it helps ensure you receive a fresh battery with better performance, a longer lifespan, and greater reliability.

Estimated delivery: 7–10 business days
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By continuing with your purchase, you acknowledge and agree to the estimated 7–10 business day delivery timeframe.
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this battery was just what I needed.

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Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

Delivery and Shipping

🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.

Disclaimer

⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.

🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.

Voltage

11.1V

Amp

4400mAh

Lenovo ThinkPad T440P / T540P / L440 / L540 — 11.1V Li-ion Replacement Battery (45N1144)

This is an 11.1V, 4400mAh (48.84Wh) Li-ion replacement battery for the Lenovo ThinkPad T440P, T540P, L440, and L540 series laptops. It matches the original cell count, voltage rail, and connector pinout. OEM part numbers covered include 45N1144, 45N1148, 45N1150, 45N1158, 45N1160, and over a dozen additional Lenovo part variants.

  • T440P / T540P / L440 / L540 compatibility: These four ThinkPad lines share the same six-cell 11.1V battery bay, connector housing, and BMS communication protocol. A single cell fits all four without modification.
  • Bench tested on actual hardware: We ran this cell on a ThinkPad T440P. The BMS handshake completed on first boot, the charge controller accepted the cell immediately, and the BIOS registered a valid battery status without requiring manual intervention.
  • Post-install calibration cycle: After fitting this battery, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on ThinkPad hardware.

BIOS reporting battery health as poor immediately after swap

ThinkPad firmware stores charge history and wear data in the old cell's EEPROM. When a new cell is fitted, the BIOS reads no accumulated cycle data and flags the battery as degraded or unknown. This is a firmware state issue, not a cell defect. Running one full discharge-to-hibernate then a full uninterrupted charge forces the BIOS to re-run its learn cycle against the new cell's actual capacity. After one or two complete cycles, the health status updates correctly.

Laptop shuts down at 20–30% charge shown on the gauge

This happens when the fuel gauge IC has not yet calibrated against the new cell's discharge curve. The old calibration data predicts a voltage floor that the new cell hits earlier under combined CPU and display load, triggering a hard cutoff before the displayed percentage reaches zero. It is not a faulty cell. Run two full discharge-to-hibernate cycles followed by full charges, and the gauge IC recalibrates its endpoint to match the new cell — shutdowns at false percentages stop after that.

Compatible Models

ThinkPad T440P ThinkPad T540P ThinkPad L440 ThinkPad L540 ThinkPad W540 ThinkPad T440(20B6S00U00) ThinkPad T440(20B6002XCD) ThinkPad T440(20B6A04UCD) ThinkPad T440p(20ANA07PCD) ThinkPad L440(20ASA18SCD) ThinkPad W540(20BHS0ME00) ThinkPad L540 20AU002Q ThinkPad W540 20BG0013US ThinkPad L440 20AT004QGE ThinkPad W540 20BH001XUS ThinkPad T540p(20BFA0Y500) ThinkPad W541 20EF000NUS ThinkPad T440(20B7S0NT0E) ThinkPad T440(20B6S00T00) ThinkPad T440(20B6S00W00) ThinkPad T440p(20ANA0AJCD) ThinkPad T440p(20AWS0KP01) ThinkPad W540(20BHS09N01) ThinkPad W540(20BHS0JJ00) ThinkPad L540 20AU000YUS ThinkPad T540p 20BE003AUS ThinkPad W540 20BH001JUS ThinkPad T540p(20BFS01C00) ThinkPad T440(20B6S00G00) ThinkPad T440(20B6S00V00) ThinkPad T440(20B6A03FCD) ThinkPad T440p(20ANA0AMCD) ThinkPad L440(20ASA1BWCD) ThinkPad W540(20BHA0C8CD) ThinkPad L440 20AS ThinkPad T440p 20AN000HUS ThinkPad W540 20BG0017US ThinkPad W540 20BH002CUS ThinkPad W541 20EF000Q ThinkPad T440(20B6A050CD) ThinkPad T440(20B6S00200) ThinkPad T440(20B6A03SCD) ThinkPad T440p(20ANA0A1CD) ThinkPad T440p-QCD ThinkPad W540(20BHS08HCD) ThinkPad L540 20AU001EUS ThinkPad T540p 20BE003DUS ThinkPad W540 20BH001LUS ThinkPad T540p(20BFS01L00) ThinkPad T540p(20BFA0YX00) ThinkPad T440(20B6A04TCD) ThinkPad T440(20B6002YCD) ThinkPad T440(20B6A03HCD) ThinkPad T440p(20ANA0DXCD) ThinkPad L440(3550M) ThinkPad W540(20BHS0MF00) ThinkPad L440 20AS000S ThinkPad T440p 20AN000KUS ThinkPad W540 20BH001AUS ThinkPad T540p(20BFA0Y300) ThinkPad W541 20EF000HUS ThinkPad T440(20B6A06TCD) ThinkPad T440(20B6S00300) ThinkPad T440(20B6A04QCD) ThinkPad T440p(20ANA092CD) ThinkPad T440p(20AW0009CD) ThinkPad W540(20BHS0MD00) ThinkPad L540 20AU002NUS ThinkPad T540p 20BE003FUS ThinkPad W540 20BH001NUS ThinkPad T540p(20BFS02J00) ThinkPad W541 20EF000KUS ThinkPad T540p(20BFS06X00) ThinkPad T440(20B6A05ACD) ThinkPad T440(20B6A07SCD) ThinkPad T440(20B6A03GCD) ThinkPad T440p(20ANS04G00) ThinkPad L440(20AT001DCD) ThinkPad W540(20BH002NCD) ThinkPad L440 20AS000U ThinkPad T440p 20AN000MUS ThinkPad W540 20BH001CUS ThinkPad T540p(20BFS01M00) ThinkPad T440(20B6A03KCD) ThinkPad T440(20B60037CD) ThinkPad T440(20B6A04VCD) ThinkPad T440p(20ANA07NCD) ThinkPad L440(20AT001ECD) ThinkPad W540(20BHS0MC00) ThinkPad L540 20AU002PUS ThinkPad T540p 20BE003HUS ThinkPad W540 20BH001WUS ThinkPad T540p(20BFA0Y200) ThinkPad W541 20EF000MUS ThinkPad T440(20B7S1AA0H) ThinkPad T440(20B6S02X00) ThinkPad T440(20B6S00Q00) ThinkPad T440(20B6A059CD) ThinkPad T440p(20AW000GCD) ThinkPad L440(20AT0019CD) ThinkPad W540(20BHS0M900) ThinkPad L540 20AU000Y ThinkPad T540p 20BE ThinkPad W540 20BH001EUS ThinkPad T540p(20BFS03F00) ThinkPad T440(20B6S02100) ThinkPad T440(20B6S00X00) ThinkPad T440(20B6A04SCD) ThinkPad T440p(20ANA07ACD) ThinkPad L440(20ASA18ECD) ThinkPad W540(20BHS0N900) ThinkPad T440p 20AN000GUS ThinkPad W540 20BG0016US ThinkPad W540 20BH001YUS ThinkPad T540p(20BFA1AR00) ThinkPad W541 20EF000PUS ThinkPad T440(20B6S01Y00) ThinkPad T440(20B6A07UCD) ThinkPad T440(20B6A05GCD) ThinkPad T440p(20ANA0ALCD) ThinkPad T440p(20ANA079CD) ThinkPad W540(20BHS0MB00) ThinkPad L540 20AU001E ThinkPad T540p 20BE003CUS ThinkPad W540 20BH001KUS ThinkPad T540p(20BFS02N00) ThinkPad T540p(20BFS0BV00) ThinkPad T440(31P20B6S01W00) ThinkPad T440(20B6A07TCD) ThinkPad T440(20B6A03ECD) ThinkPad T440p(20ANA0E0CD) ThinkPad L440(20AT001BCD) ThinkPad W540(20BHS0MA00) ThinkPad L440 20AS0003US ThinkPad T440p 20AN000JUS ThinkPad W540 20BH0019US ThinkPad T540p(20BFS02MCD) ThinkPad W540 20BH002QUS ThinkPad T440(20B6A06PCD) ThinkPad T440(20B6S00400) ThinkPad T440(20B6A069CD) ThinkPad T440p(20ANA0E1CD) ThinkPad T440p(20ANS01Q00) ThinkPad W540(20BH002GCD) ThinkPad L540 20AU002N ThinkPad T540p 20BE003EUS 20AT0019CD ThinkPad W540 20BH001MUS ThinkPad T540p(20BFS03H00) ThinkPad T540p(20BFS07000) ThinkPad T440(20B6S06T00) ThinkPad T440(20B6S00P00) ThinkPad T440(20B6A03NCD) ThinkPad T440p(20AWS0KN01) ThinkPad L440(20AT001CCD) ThinkPad W540(20BH002PCD) ThinkPad L440 20AS000SUS ThinkPad T440p 20AN000LUS ThinkPad W540 20BH001BUS ThinkPad T540p(20BFA0Y400) ThinkPad W541 20EF000JUS ThinkPad T440(20B6A0BCCD) ThinkPad T440(20B6S00M00) ThinkPad T440(20B6A04RCD) ThinkPad T440p(20ANA0AKCD) ThinkPad L440(20AT000YCD) ThinkPad W540(20BHS0M800) ThinkPad L540 20AU002P

Replaces Part Numbers

45N1144 45N1148 45N1150 45N1158 45N1160 45N1145 45N1149 45N1151 45N1159 45N1161 45N1147 45N1153 0A36302 0C52863 0C52864 45N1152 45N1162 45N1769 45N1779

Technical Specifications

Voltage11.1V
Amp Hours4400mAh
Capacity4400mAh
Rate48.84Wh
Net Weight309g /10.90 oz
Gross Weight459g /16.19 oz
Approximate Weight459g /16.19 oz
Dimension 205.90 x 50.90 x 20.40mm

Product Highlights

  • Brand: Lenovo
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

The ThinkPad BIOS shows the replacement battery as 0% or "Unknown" right after I installed it — is the cell dead?

The cell is not dead. The BIOS is reading EEPROM charge history from the old battery and finding none on the new cell, so it flags an unknown or zero state. Run the laptop down to hibernate-cutoff, then charge it uninterrupted to 100%. That single learn cycle is enough for the BIOS to register the new cell and display a real percentage.

My T440P is reporting this battery as 38Wh in system info, but the spec says 48.84Wh — why is it showing the wrong capacity?

The Wh figure displayed in system info is pulled from the cell's EEPROM, which is pre-populated with the rated chemistry baseline before calibration cycles have run. The fuel gauge IC updates that figure as it maps actual charge and discharge curves against the new cell. After two full discharge-to-full-charge cycles, the displayed Wh value stabilises and aligns with the rated 48.84Wh.

The battery charges to about 80% then stops — is the charge controller rejecting the new cell?

The charge controller is not rejecting the cell. Lenovo's BIOS includes a charge threshold setting — often called "Conservation Mode" — that caps charging at 80% to reduce cell stress during constant desk use. Open Lenovo Vantage (or ThinkPad Battery Manager on older installs), navigate to the battery charge threshold settings, and set the upper limit to 100%. The cell will then charge fully on the next cycle.

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