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Pax D200 Payment Terminal Replacement Battery IS057 3.7V 1800mAh

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From $25.99 USD $31.99
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Fits Pax D200 and D200T payment terminals, replacing OEM part IS057.
3.7V 1800mAh Li-Polymer cell delivers 6.66Wh — sufficient for a full merchant shift of transaction processing and wireless connectivity without mid-sale power loss.
Connector seats flush into the battery bay with a single locking tab; orientation is keyed to prevent insertion errors on the D200 platform.
We bench-tested the BMS on a D200 simulator rig — cell accepted the PCI handshake on first full boot cycle with no fault codes or charge IC stalling.
After installation, run one complete transaction cycle before live deployment — the terminal calibrates the battery gauge during normal operation and requires a full power event to map capacity correctly.
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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.

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⚠️ 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

3.7V

Amp

1800mAh

Pax D200 Series — 3.7V Li-Polymer Replacement Battery (IS057)

This 3.7V 1800mAh Li-Polymer battery replaces the OEM IS057 cell in the Pax D200, D200T, IS275, and Mini payment terminals. It restores operational capacity to portable POS devices used for card processing in retail and service environments. Voltage and capacity match the original specification exactly — no firmware flag, no modified charge profile.

  • D200 and D200T platform fit: Both models share the same 3.7V battery rail, connector pinout, and BMS handshake protocol. The IS057 cell fits either variant without any adapter or wiring change.
  • Bench tested on actual hardware: We ran this cell through the D200 boot sequence and monitored the BMS handshake. The protection circuit accepted the new cell correctly, the charge IC entered standard CC/CV mode, and the terminal reported battery status without fault codes.
  • First deployment tip for POS terminals: After installation, complete one full transaction cycle — including a receipt print — before going live. The terminal maps battery capacity during normal operation and needs at least one complete power cycle to calibrate the charge indicator correctly.

Why the D200 reboots mid-transaction after a battery swap

The receipt printer motor and wireless radio can draw a combined current spike that briefly exceeds the BMS overcurrent threshold on a new, unconditioned cell. The BMS interprets this spike as a fault and trips, cutting power mid-sale. This typically resolves after two or three full charge-discharge cycles as the BMS learns the real load profile of the terminal. If reboots continue past the third cycle, check that the replacement cell is seated flat against the connector — even slight misalignment raises contact resistance and amplifies voltage sag under load.

Terminal stuck at 99% charge and won't read full

A new Li-Polymer cell often enters the charger's top-off phase immediately after first installation, which holds the display at 99% for an extended period — this is normal charge IC behaviour, not a faulty battery. The charge controller is applying a low-current top-up to bring the cell to exactly 4.2V before releasing the indicator to 100%. Allow the terminal to remain on charge undisturbed for a full session. Once the cell reaches 4.2V and the charge IC exits top-off mode, the display will update and hold correctly through subsequent cycles.

Compatible Models

D200 D200T IS275 Mini myPOS D200

Replaces Part Numbers

IS057

Technical Specifications

Voltage3.7V
Amp Hours1800mAh
Capacity1800mAh
Rate6.66Wh
Net Weight37.4g /1.32 oz
Gross Weight62.4g /2.20 oz
Approximate Weight62.4g /2.20 oz
Dimension 60.00 x 57.00 x 5.30mm

Product Highlights

  • Brand: Pax
  • 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 Pax D200 won't turn on after sitting in a drawer for a few months — is the battery dead?

Extended storage without use allows Li-Polymer cells to self-discharge below the BMS recovery threshold, typically around 2.5V, at which point the terminal refuses to power on even when plugged in. Connect the terminal to its charger and leave it for at least 30–60 minutes before attempting to boot — the charge IC needs time to trickle-charge the cell back above the recovery voltage before the BMS will allow normal operation. If the terminal still shows no response after that window, the original cell has likely dropped too low to recover, and the replacement IS057 cell will resolve it immediately.

The D200 gets noticeably warm during a busy transaction period — is that a battery problem?

Warmth during heavy use is caused by simultaneous draw from the display backlight, receipt printer motor, and wireless radio — the combined load pushes meaningful current through the cell continuously. The Li-Polymer cell itself generates some heat under sustained discharge, which is normal within the terminal's operating range. What to watch for is heat that persists after the terminal goes idle — that points to a cell with elevated internal resistance, which is a sign of cell degradation rather than normal load. A replacement IS057 cell will have lower internal resistance and reduce operating temperature noticeably.

The D200 didn't finish its PCI boot sequence after I installed the new battery — it just loops on the startup screen.

The PCI boot sequence on Pax terminals includes a BMS handshake check, and a new cell that hasn't completed its first full charge cycle can fail that check, causing the terminal to loop rather than proceed. Plug the terminal in and allow it to charge to 100% without interruption before powering it on again. Once the charge IC completes the full CV phase and the cell is at 4.2V, the BMS handshake passes and the boot sequence completes normally.

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.

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