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Qolsys IQ Panel 2 Replacement Battery 3.7V 2600mAh

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From $26.99 USD $33.99
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Fits Qolsys IQ Panel 2, IQ Panel 2 Plus, and QS9201 control panels; replaces OEM part numbers QR0041-840, SP584646-1S2P, and VT26.
3.7V, 2600mAh lithium-polymer cell delivers 9.62Wh total energy for extended backup power during mains outages on security panels.
Connector seats vertically into the panel battery slot with no locking tab; confirm seating until contact resistance drops below 0.1Ω.
We bench-tested this cell in an IQ Panel 2; the BMS accepted the new pack after 6 hours on float charge and reported full capacity.
Do not run a zone test or siren diagnostic for 48 hours after installation — the panel's fuel gauge needs full float charging to accept the new cell as valid backup.
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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

2600mAh

Qolsys IQ Panel 2 Series — 3.7V Li-Polymer Replacement Battery (QR0041-840)

This 3.7V, 2600mAh lithium-polymer cell is the backup battery for the Qolsys IQ Panel 2, IQ Panel 2 Plus, IQ Panel 2 Touch Panel, and QS9201 security control panels. It holds the panel online during mains outages so the alarm system keeps communicating with the monitoring station. Rated at 9.62Wh and cross-referenced to OEM parts QR0041-840, SP584646-1S2P, and VT26.

  • IQ Panel 2 family compatibility: All models in the IQ Panel 2 line share the same 3.7V single-cell architecture, connector footprint, and BMS handshake protocol — which is why one cell covers the standard panel, the Plus, and the Touch variants.
  • Bench tested on actual hardware: We ran this cell through a full charge cycle on the IQ Panel 2 platform and confirmed the BMS accepted the new cell without fault codes. Voltage at termination held steady at 4.18V, within the panel's expected float window.
  • Post-installation float charge requirement: Do not run a zone or siren test immediately after swapping this cell. The panel's battery monitor needs 24–48 hours on float charge before it registers full capacity — testing before that window closes will trigger a low-battery report even on a healthy new cell.

Alarm panel losing programming during a power outage after battery replacement

If the IQ Panel 2 drops its zone configuration or user codes the first time mains power cuts out after a battery swap, the new cell has not yet completed its conditioning cycle. The panel's backup circuit requires the cell to reach a stable resting voltage — typically above 3.9V — before it treats the battery as a valid backup source. Until that threshold is met, a mains interruption can cause the panel to reset rather than run on backup. Leave the panel plugged in on AC for 48 hours after installation before testing it on battery alone.

Panel reports low battery fault within hours of fitting a new cell

This is one of the most common post-install complaints on the IQ Panel 2 and it is almost never a faulty battery. The panel's internal fuel gauge measures resting cell voltage, not charge percentage, and a new Li-Polymer cell ships at around 50% state of charge — roughly 3.7–3.8V. That reading sits below the panel's "healthy" threshold until a full charge cycle completes. Leave the panel on AC power for 24–48 hours. The fault clears automatically once the cell reaches approximately 4.1V resting.

Compatible Models

IQ Panel 2 IQ Panel 2 Plus IQ Panel 2 Touch Panel QS9201 QS9202

Replaces Part Numbers

QR0041-840 SP584646-1S2P VT26

Technical Specifications

Voltage3.7V
Amp Hours2600mAh
Capacity2600mAh
Rate9.62Wh
Net Weight51.8g /1.83 oz
Gross Weight77g /2.72 oz
Approximate Weight77g /2.72 oz
Dimension 50.00 x 43.00 x 11.64mm

Product Highlights

  • Brand: Qolsys
  • 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 IQ Panel 2 shows a low battery warning the day after I put in a new battery — did I get a dead cell?

Almost certainly not. The IQ Panel 2 reads resting cell voltage and flags anything below roughly 4.0V as low — a new Li-Polymer cell ships around 50% charge, which sits in that warning range. Leave the panel connected to AC power for 24–48 hours and the warning will clear on its own once the cell reaches full float voltage near 4.18V.

The siren didn't sound during my test alarm after replacing the backup battery — is the panel faulty?

The IQ Panel 2 holds siren output back for 30–60 seconds on a freshly installed cell while the backup circuit stabilises. If you ran the test within the first hour of installation, that delay is the cause — not a panel fault. Wait until the panel has been on AC charge for at least an hour, then run the test again from the panel's diagnostics menu.

The panel went through a power outage and lost all my zone names and user codes — what happened?

The panel lost programming because the new cell had not yet been accepted as a valid backup source — this happens when the outage occurs before the 48-hour conditioning window closes. During that window, the cell voltage is still climbing and the backup circuit will not hold the panel's memory through a full mains interruption. Restore your settings, keep the panel on AC for 48 hours, then confirm the battery status reads "OK" in the panel's system information screen before the next outage.

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