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

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

Sunmi L2KS POS Terminal Replacement Battery 3.87V 5000mAh

Up to 20% off
New arrival
From $56.99 USD $70.99
Shipping calculated at checkout.
Fits Sunmi L2KS and T8A10 payment terminals; replaces OEM part JKRA battery pack.
3.87V, 5000mAh Li-Polymer cell restores full transaction capacity to aging terminals.
Connector seats vertically into the battery slot behind the rear cover panel.
Bench testing on the L2KS showed stable BMS handshake and 4.2V peak charge voltage.
After installation, run one complete transaction cycle before deploying live—the terminal calibrates charge indicator during normal operation.
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

3.87V

Amp

5000mAh

Sunmi L2KS / T8A10 — 3.87V Li-Polymer Replacement Battery (JKRA)

This is a 3.87V, 5000mAh Li-Polymer battery for the Sunmi L2KS and T8A10 portable POS terminals. It replaces the OEM JKRA cell when the original degrades from daily charge cycles. The L2KS is an Android-based payment terminal used in retail and hospitality — keeping it powered through a full shift matters.

  • L2KS and T8A10 compatibility: Both models share the same 3.87V cell format, connector pinout, and BMS handshake protocol — one battery covers both units without modification.
  • Bench tested on actual hardware: We ran this cell through multiple boot cycles on the L2KS platform. The BMS handshake completed correctly, charge IC entered CC/CV mode as expected, and cutoff voltages held within spec under combined display, wireless, and printer load.
  • First deployment tip for payment terminals: After installation, complete one full transaction cycle before deploying in a live environment. The terminal maps battery capacity during normal operation and needs at least one complete power cycle to calibrate the charge indicator correctly.

Why the L2KS reboots mid-transaction after a battery swap

The L2KS draws a short current spike when the thermal printer fires during receipt printing. On a new cell that hasn't completed an initial charge cycle, the BMS may read this spike as an overcurrent event and cut the output rail — causing an instant reboot. This isn't a faulty battery. Run the terminal through one full charge and at least one complete transaction before live deployment. The BMS learns the load profile and the trip threshold adjusts accordingly.

Terminal stuck on boot screen and not completing PCI sequence after install

The L2KS PCI boot sequence requires a stable voltage rail above 3.6V to complete the security chip initialisation. A new cell shipped at storage charge (~3.75V) can sit close to the minimum threshold, especially if the unit sat unused. If the terminal stalls on the boot screen, connect it to the charger and let it reach at least 4.0V before attempting to power on. One full charge cycle resolves this in almost every case.

Compatible Models

L2KS T8A10

Replaces Part Numbers

JKRA

Technical Specifications

Voltage3.87V
Amp Hours5000mAh
Capacity5000mAh
Rate19.35Wh
Net Weight82g /2.89 oz
Gross Weight107g /3.77 oz
Approximate Weight107g /3.77 oz
Dimension 72.10 x 47.60 x 10.10mm

Product Highlights

  • Brand: Sunmi
  • 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 Sunmi L2KS battery indicator has been stuck at 99% since I installed the new cell — is it broken?

No — this is the charge IC holding the new cell in top-off mode. A fresh Li-Polymer cell arrives slightly below full charge, so the controller keeps topping it up rather than declaring it complete. Let the terminal sit on charge for a full uninterrupted cycle without removing it. Once the IC exits top-off mode, the indicator will drop to 100% and behave normally on subsequent charges.

The L2KS won't power on at all — it was sitting unused in a drawer for a few months.

Extended storage without charging can push the cell below the BMS recovery threshold, typically under 3.0V. At that voltage, the protection circuit locks output to prevent damage and the terminal appears completely dead. Connect the charger and leave it for at least 30 minutes before pressing the power button — most BMS circuits require a slow pre-charge phase to recover a deeply discharged cell before they allow normal output.

The Sunmi L2KS feels noticeably warm during a busy transaction period — is the new battery causing this?

The warmth comes from the combined draw of the display, Wi-Fi or 4G radio, and the thermal printer firing repeatedly — not the battery alone. A 5000mAh Li-Polymer cell under that stacked load will generate some heat, which is normal. If the terminal gets hot enough to trigger a thermal warning or shut down, check that the device isn't enclosed in a case that traps heat, and confirm the printer paper feed isn't causing extended motor run time on each receipt.

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

Sunmi L2KS Replacement Battery, 3.87V, 5000mAh, 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