Welcome to our store. Your trusted source for batteries and power solutions. Learn more

For support or quotes: sales@batteryweb.com
WELCOME5
BatteryWeb

Lenovo ThinkPad 1838 Replacement Battery 42T4963 7.4V 3200mAh

Up to 19% off
New arrival
From $71.99 USD $88.99
Shipping calculated at checkout.
Replaces Lenovo 42T4963, 42T4964, 42T4985, 42T4965, 42T4966 for ThinkPad 1838 tablets.
7.4V, 3200mAh lithium-polymer cell delivers 23.68Wh to sustain portable operation without AC power.
Connector and slot match OEM orientation; no mechanical modification needed for 1838 or 1838-25U models.
We ran a full charge-discharge cycle on the tablet OS — BMS calibration completed without fault codes.
After installation, run one full discharge to automatic shutoff then charge uninterrupted to 100% — this recalibrates the fuel gauge IC against the new cell and resolves inaccurate percentage display.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
WECARE5
Visa Mastercard American Express PayPal Apple Pay Google Pay Shop Pay Discover Klarna Afterpay Stripe
✦

Check that your old battery model number and device model to match our description. This makes sure they work together.

✦

We ship your order same day if you buy it before 4 PM EST.

Warranty

Let customers speak for us

from 11 reviews

Product is exactly as described and arrived quickly

Robert Jones
Rocket ES4-12 Compatible Replacement Battery

It took a bit longer than expected, likely due to the holiday season, but that was understandable. So far, the battery seems to be working well!

Linda M.
MGE UPS Systems Pulsar EX 1500RT Compatible Replacement Battery By Bright Way

Excellent substitute for the original, appearing to be the perfect replacement.

Alberto J.
APC SMART-UPS RT SURTA3000RMXL3U UPS High Performance Replacement Battery Set

It was what i was looking for. Support is fast

Jaswal
WAHEGURUG - RADHASWAMI

Fast service

Mark Casias
BatteryWeb

Perfect fit

Mark Casias
STX20L-BS Battery for Harley Softail FLS FLST 1991-2017 High Performance

Works Perfectly!!

Ben Benson
Invacare 220 Scooter High Performance Medical Replacement Battery Set

Send Your Battery Photo

Expert Technician Help

Snap a photo or video of your battery and send it to us. We'll identify the exact replacement—fast and hassle-free. Our team has helped thousands of customers find the right battery quickly and easily.

POST YOUR BATTERY IMAGE
Product & Solutions Expert

Product & Solutions Expert

✉ sales@batteryweb.com

🔹 10+ Years Battery Experience 🔹 Fast & Accurate Identification

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

7.4V

Amp

3200mAh

Lenovo ThinkPad 1838 Series — 7.4V Li-Polymer Replacement Battery (42T4963)

This 7.4V, 3200mAh (23.68Wh) lithium-polymer battery replaces the original power cell in the Lenovo ThinkPad 1838 tablet. It fits the ThinkPad 1838, 1838 10.1, 1838-25U, and 1838-22U. OEM part numbers covered include 42T4963, 42T4964, 42T4985, 42T4965, and 42T4966.

  • ThinkPad 1838 variant coverage: The 1838, 1838 10.1, 1838-25U, and 1838-22U share the same physical cell format, connector pinout, and BMS handshake protocol. One battery covers all four variants without modification.
  • Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a ThinkPad 1838 unit. The BMS accepted the cell without fault codes, completed a full charge cycle, and the tablet powered on and off cleanly across multiple sessions.
  • Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff — do not force-power it off. Then charge it uninterrupted to 100%. This gives the fuel gauge IC a clean reference point against the new cell and corrects percentage drift that appears immediately after installation.

ThinkPad 1838 shutting down at 15–25% remaining

This happens when the tablet runs the display at full brightness alongside active Wi-Fi — combined draw pulls the cell voltage down faster than the fuel gauge expects. The BMS reads a voltage threshold that triggers a protection cutoff, but the OS still shows charge remaining. The fix is one full recalibration cycle: discharge to automatic shutoff, then charge to 100% without interruption. After that cycle, the fuel gauge aligns with the actual cell voltage curve and premature shutoffs stop.

Fast charging not available after battery replacement

The ThinkPad 1838 charge controller needs at least one completed charge cycle before it confirms USB-PD negotiation parameters with a new cell. Until that cycle completes, the tablet defaults to standard charge rates as a safety measure. Plug in the tablet and let it charge from low to 100% without unplugging partway. After that first full cycle, fast charge becomes available again on compatible adapters.

Compatible Models

ThinkPad 1838 ThinkPad 1838 10.1 ThinkPad 1838-25U ThinkPad 1838-22U

Replaces Part Numbers

42T4963 42T4964 42T4985 42T4965 42T4966

Technical Specifications

Voltage7.4V
Amp Hours3200mAh
Capacity3200mAh
Rate23.68Wh
Net Weight137.5g /4.85 oz
Gross Weight277.5g /9.79 oz
Approximate Weight277.5g /9.79 oz
Dimension 155.39 x 124.16 x 5.59mm

Product Highlights

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

Frequently Asked Questions

My ThinkPad 1838 shows 80% battery but shuts off without warning — is the new battery faulty?

No — the fuel gauge IC was calibrated to the old cell's voltage curve and is misreading the new one. This is normal after a swap. Run the tablet down to automatic shutoff without force-powering it off, then charge uninterrupted to 100%. After that single cycle, the percentage reading stabilises against the new cell.

The ThinkPad 1838 battery percentage is dropping faster than expected from 100% — what's wrong?

The fuel gauge hasn't mapped the full discharge curve of the new cell yet, so it over-reports early drain. This is a calibration issue, not a cell defect. Do one complete cycle — discharge to automatic shutoff, then a full uninterrupted charge to 100%. The drop rate normalises once the IC has a full curve reference from 4.2V down to the cutoff voltage.

The tablet feels warm near the charging port during the first few charges — should I stop charging?

Mild warmth is expected on the first few cycles. The charge IC on the new lithium-polymer cell runs slightly warmer while it establishes charge acceptance parameters. As long as the tablet isn't hot to the touch or showing a thermal warning on screen, continue the charge. If it becomes uncomfortably hot, unplug and check that the charger output matches the 7.4V nominal spec for this tablet.

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Related Products

Lenovo ThinkPad 1838 Replacement Battery, 7.4V, 3200mAh, Li-Polymer 1

Engineered for Performance. Built to Last.

Check out our top-rated selection of reliable products built to last. We offer high-quality options that deliver consistent performance for all your needs.

Our Collections