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Brondi Smartphone S S572 Compatible Battery 3.8V 2900mAh

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From $35.99 USD $44.99
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Fits Brondi Smartphone S model S572; replaces OEM battery part S572.
3.8V and 2900mAh capacity sustains the phone's modem and display without mid-cycle voltage sag.
Connector slides into the battery slot with flat orientation; locking tab secures against the housing frame.
We bench-tested this cell in the S572 chassis; BMS accepted the charge handshake and held 3.8V under sustained load draw.
On first use after installation, disable fast charging for one complete discharge-charge cycle to let the fuel gauge IC recalibrate against the new cell curve.
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.

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

3.8V

Amp

2900mAh

Brondi Smartphone S — 3.8V Li-Polymer Replacement Battery (S572)

This is a 3.8V, 2900mAh Li-Polymer battery for the Brondi Smartphone S (OEM part S572). It replaces the original cell when the phone no longer holds adequate charge. Voltage, capacity, and connector match the factory specification.

  • Brondi Smartphone S fit: The S572 part number covers the Smartphone S platform. The connector orientation, BMS handshake voltage, and physical footprint — 84.00 × 60.00 × 4.20mm — are specific to this model. No modification needed to fit the battery compartment.
  • Bench tested on actual hardware: We cycled this cell through charge and discharge on the Smartphone S platform. The BMS accepted the cell without error flags, and the charge IC ramped normally through CC and CV phases to full termination voltage.
  • Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.

Why the Brondi Smartphone S reports wrong battery percentage after a cell swap

The fuel gauge IC builds its percentage model from the discharge curve of the original cell over many cycles. When a new cell goes in, the stored curve no longer matches actual cell behaviour. The result is a percentage reading that jumps, stalls, or reads 100% then drops suddenly. One full discharge-charge cycle lets the coulomb counter reset its reference and re-anchor the percentage to the new cell's actual capacity.

Sudden shutdown at 20–30% remaining on the Brondi Smartphone S

This is a voltage cliff — the cell voltage drops below the threshold the modem and display require under peak load, even though the fuel gauge still shows charge remaining. It happens most often when the fuel gauge IC is still calibrated to the old, degraded cell. The BMS trips to protect the cell before the OS can complete a clean shutdown. Run one full discharge to 0% (phone-reported) followed by a full charge to let the fuel gauge recalculate the low-voltage cutoff point against the new cell.

Compatible Models

Smartphone S S572

Replaces Part Numbers

S572

Technical Specifications

Voltage3.8V
Amp Hours2900mAh
Capacity2900mAh
Rate11.02Wh
Net Weight46g /1.62 oz
Gross Weight96g /3.39 oz
Approximate Weight96g /3.39 oz
Dimension 84.00 x 60.00 x 4.20mm

Product Highlights

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

Frequently Asked Questions

My Brondi Smartphone S won't turn on at all after the replacement battery sat unused for a few weeks — is the new battery dead?

Unlikely dead — the BMS has tripped into lockout because cell voltage dropped below 2.5V during storage. Plug in the original charger and leave it for 20–30 minutes without pressing the power button; the charge IC needs to trickle current into the cell before the BMS will re-initialise. If the screen stays black past that point, check the charge port is fully seating the cable, then try again — the phone should show a low-battery icon once the cell clears the BMS recovery threshold near 2.8V.

Fast charging stopped working on my Brondi Smartphone S after fitting this battery — it only charges slowly now.

The USB-PD or proprietary fast-charge handshake can fail on the first cycle with a new cell because the BMS presents higher impedance than the charge IC expects. We saw this on the bench — the phone defaulted to standard 5V charging until the cell completed one full charge cycle. Run one complete slow charge to 100%, then disconnect and reconnect the charger; the fast-charge protocol should re-negotiate correctly once the charge IC has profiled the new cell's impedance.

The battery percentage on my Brondi Smartphone S is jumping around erratically — it went from 60% to 85% without charging.

The coulomb counter inside the fuel gauge IC is recalibrating against the new cell's discharge curve, which differs from the worn cell it was trained on. The percentage will stabilise after one or two full discharge-charge cycles as the IC builds a new reference map. Do not interrupt cycles mid-way during this period. After two complete cycles, if the percentage still jumps by more than 5–10%, force a full discharge to 0% (phone-reported shutdown) and charge uninterrupted to 100%.

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