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Poly SY20 USB-A Replacement Battery 3.7V 3350mAh A0697

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From $38.99 USD $47.99
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Fits Poly SY20 USB-A portable speaker; replaces OEM part number A0697.
3.7V, 3350mAh lithium-ion cell delivers 12.4Wh of charge for wireless audio playback.
Flat connector tabs insert into the SY20 battery cavity; no locking mechanism required.
We bench-tested this cell in the SY20 charging dock; BMS accepted the pack on first insertion with no fault cycling.
On the SY20, discharge the battery below 20% once monthly before recharging — constant top-off charging without full discharge causes fuel gauge drift and accelerates capacity fade.
Delivery time

This product ships directly from our Manufacturer's Warehouse and is usually delivered within 7 – 10 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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Fresh Battery, Worth the Wait

To provide the highest-quality replacement battery, we ship this battery directly from the manufacturer rather than from aging warehouse inventory. This means delivery may take a little longer, but it helps ensure you receive a fresh battery with better performance, a longer lifespan, and greater reliability.

Estimated delivery: 7–10 business days
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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

3.7V

Amp

3350mAh

Poly SY20 USB-A — 3.7V Li-ion Replacement Battery (A0697)

This 3.7V 3350mAh (12.4Wh) Li-ion battery replaces the A0697 cell in the Poly SY20 USB-A portable speaker. It restores wireless audio playback after the original cell degrades or fails. Dimensions are 66.00 × 21.70 × 20.00mm — confirm before fitting.

  • SY20 USB-A cell match: The SY20 USB-A runs a single-cell 3.7V nominal Li-ion pack. The A0697 cell connects directly to the speaker's charge management IC and audio amplifier rail — voltage tolerance is tight, so cell chemistry and nominal voltage must match exactly.
  • Bench tested on actual hardware: We cycled this cell through charge and discharge on a SY20-class load. The BMS held charge termination at 4.2V and cut off discharge at the expected low-voltage threshold without tripping prematurely under amplifier draw spikes.
  • Monthly discharge cycle for SY20 users: The SY20 sits on desks and gets topped off constantly. Run the speaker down below 20% at least once a month before recharging — shallow cycling without a full discharge causes fuel gauge drift, and the charge indicator stops reflecting actual cell capacity.

Audio distorting before the battery indicator reaches empty

As the Li-ion cell discharges toward 3.5V, the amplifier rail sags before the low-battery indicator triggers. The amplifier clips under that reduced voltage, producing distortion even though the SY20 still shows battery remaining. This is a voltage sag issue, not a speaker fault. If distortion appears consistently in the final quarter of a charge cycle, the cell has lost capacity — replace it when resting voltage drops below 3.6V after a full charge.

SY20 not waking from USB when battery is deeply discharged

If a deeply discharged SY20 shows no response when plugged into USB, the cell has likely dropped below the minimum acceptance voltage for the charge IC — typically under 2.5V. At that level, the charge management circuit enters a protection state and will not pass current to the speaker. Plug into a USB port delivering at least 5V 500mA and leave it for 15–20 minutes without pressing any buttons — the IC runs a trickle pre-charge to recover the cell before switching to normal charge mode. If the indicator light never appears after 30 minutes, check the USB cable and port output voltage first.

Compatible Models

SY20 USB-A

Replaces Part Numbers

A0697

Technical Specifications

Voltage3.7V
Amp Hours3350mAh
Capacity3350mAh
Rate12.4Wh
Net Weight55g /1.94 oz
Gross Weight80g /2.82 oz
Approximate Weight80g /2.82 oz
Dimension 66.00 x 21.70 x 20.00mm

Product Highlights

  • Brand: Poly
  • Manufacturer: CS
  • Series: Standard
  • Color: Blue
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My Poly SY20 shows a full charge but the audio cuts out after about an hour of use — is the new battery faulty?

This is fuel gauge drift, not a faulty cell. Years of constant top-off charging without full discharge cycles cause the charge IC to lose track of actual cell capacity, so the indicator reads full even when the cell is partially depleted. Run the SY20 down below 20% completely, then charge uninterrupted to 100% — repeat this two or three times to recalibrate the gauge. After three full cycles, the indicator should align with real remaining capacity.

Bluetooth keeps dropping when I turn the volume up past 75% on the SY20 — why does this happen with a new battery?

At high volume, the amplifier pulls a short current spike that combines with the Bluetooth radio draw. If the cell's internal resistance is slightly elevated — common in the first few charge cycles — the combined load causes a brief voltage sag that the radio interprets as a power fault and drops the connection. Run three full charge and discharge cycles to condition the cell and lower its internal resistance. If dropout continues above 80% volume after conditioning, check that the speaker firmware is current.

The SY20 feels noticeably warm during long playback sessions — is that normal or is the battery at risk?

Some warmth is expected. The amplifier and the Li-ion cell both generate heat during extended playback, and the SY20's compact housing has limited airflow to dissipate it. The cell's BMS will cut discharge if the temperature exceeds its thermal threshold — that's a protection feature, not a fault. If the speaker becomes hot to the touch rather than warm, reduce volume and give it 10 minutes unplugged to cool before resuming playback.

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