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Sunmi P2 Mini Replacement Battery FR020 3.8V 2500mAh

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From $36.99 USD $45.99
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Fits Sunmi P2 Mini payment terminal, replaces OEM part FR020 and SW-FR020 battery.
3.8V, 2500mAh lithium-ion cell delivers 9.5Wh to sustain full transaction cycles without mid-sale shutdown.
Connector slides into vertical slot on terminal rear with single locking tab; no tools required.
We bench-tested this cell in P2 Mini hardware — BMS accepted on first boot, no handshake delay observed.
After installation, complete one full transaction cycle before live deployment so the terminal calibrates battery capacity on its charge indicator.
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
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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

3.8V

Amp

2500mAh

Sunmi P2 Mini — 3.8V Li-ion Replacement Battery (FR020)

This 3.8V, 2500mAh Li-ion battery replaces the original FR020 cell in the Sunmi P2 Mini payment terminal. It fits the compact P2 Mini form factor directly, using the same 65.50 x 58.00 x 5.30mm dimensions as the factory unit. Merchants running the P2 Mini for card payments install this when the original cell no longer holds charge through a shift.

  • P2 Mini platform fit: The P2 Mini uses a fixed voltage rail at 3.8V with a proprietary connector and BMS handshake. This cell matches that spec. Swapping a mismatched voltage cell trips the protection circuit and the terminal won't boot.
  • Bench tested on actual hardware: We cycled this cell through the P2 Mini's charge IC and confirmed the BMS accepted the handshake without fault flags. The charge controller entered top-off mode correctly at full capacity.
  • First deployment tip: After installation, run one complete transaction cycle before deploying in a live environment. The P2 Mini maps battery capacity during normal operation and needs at least one full power cycle to calibrate the charge indicator correctly.

Why the P2 Mini reboots mid-transaction after a battery swap

The P2 Mini's receipt printer draws a short current spike when it fires — often 1.5A or more for a fraction of a second. On a new cell that hasn't completed a full charge-discharge cycle, the BMS can read that spike as an overcurrent event and cut output. The terminal reboots. Running one full transaction cycle after installation lets the BMS learn the device's normal draw profile and stop tripping on printer pulses.

Terminal not powering on after sitting unused in a drawer

Li-ion cells that sit uncharged for weeks can drop below the BMS recovery threshold — typically around 2.5V to 2.7V per cell. Below that, the protection circuit blocks output entirely as a safety measure and the terminal shows nothing on screen. Connect the original Sunmi charger and leave it for 20–30 minutes without pressing any buttons; the charge IC will attempt a trickle pre-charge to bring the cell above 3.0V before resuming normal charging.

Compatible Models

P2 Mini

Replaces Part Numbers

FR020 SW-FR020

Technical Specifications

Voltage3.8V
Amp Hours2500mAh
Capacity2500mAh
Rate9.5Wh
Net Weight46g /1.62 oz
Gross Weight71g /2.50 oz
Approximate Weight71g /2.50 oz
Dimension 65.50 x 58.00 x 5.30mm

Product Highlights

  • Brand: Sunmi
  • 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

My P2 Mini shows 99% charge and won't move off that number — is the battery faulty?

No. On a new Li-ion cell, the charge IC enters top-off mode and holds at 99% while it finishes balancing the cell to full capacity. This is normal behaviour on the P2 Mini's charge controller and usually clears after the first complete charge-discharge cycle. Run the terminal through one full transaction session until it prompts a low-battery warning, then recharge to 100% and the indicator will track correctly from that point.

The terminal completes the PCI boot screen then shuts off before reaching the home screen — what's happening?

The P2 Mini runs a PCI security sequence during boot that pulls more current than standby. If the BMS hasn't yet completed its handshake with the terminal's charge IC — common on first installation — the protection circuit can interpret the boot-sequence draw as abnormal and cut output. Charge the terminal fully before the first boot, then power it on while still connected to the charger. Once it completes one full boot on charge, the BMS registers the load profile and the issue stops.

The P2 Mini gets noticeably warm during a busy transaction period — is that a battery problem?

Not necessarily a fault. During heavy use, the P2 Mini is running its display, wireless radio, and receipt printer simultaneously, which stacks current draws on a single 2500mAh cell. Some surface warmth is normal under that combined load. If the terminal becomes hot enough to trigger a thermal warning or shuts down, check that the back cover is seated correctly — a partially open cover reduces heat dissipation and the terminal's thermal sensor will cut the battery output before damage occurs.

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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