Qolsys IQ Panel 4 Replacement Battery 3.7V 2600mAh

Qolsys IQ Panel 4 Series — 3.7V Li-ion Replacement Battery (QR0083-840)

This is a 3.7V 2600mAh Li-ion replacement cell for the Qolsys IQ Panel 4 security control panel. It fits the IQP4005, IQP4004BLK, IQ Panel 4 PowerG, and related variants. The battery provides backup power so the panel continues monitoring sensors, triggering alarms, and sending alerts during a mains power failure.

• IQ Panel 4 series compatibility: All IQ Panel 4 variants share the same 3.7V single-cell architecture, connector pinout, and BMS handshake protocol. One cell covers the full lineup without modification.
• Bench tested on actual hardware: We ran this cell on an IQP4005 and confirmed the BMS accepted the new battery, cleared the low-battery fault, and held float charge without error flags after the 48-hour conditioning window.
• Post-installation charge requirement: Do not run a zone diagnostic test immediately after swapping the cell. The panel's BMS needs 24–48 hours at float charge before it reports accurate battery status. Testing before that window expires will trigger a false low-battery alert on the panel display.

Alarm panel losing programming during a power outage after battery replacement

A freshly installed cell that has not completed its conditioning cycle cannot sustain the panel's logic board through a mains dropout. The IQ Panel 4 draws a brief high-current spike when it switches to battery mode, and a cell below full charge may sag below the BMS cutoff threshold at that moment. When that happens, the panel resets and may lose zone assignments or user codes. Install the new battery and leave the panel on mains power for a full 48 hours before allowing a power interruption to occur.

Panel shows low battery fault hours after fitting a new cell

This is a BMS reporting delay, not a faulty cell. The IQ Panel 4 reads battery state through a fuel-gauge circuit that needs to observe at least one partial charge-discharge cycle before it trusts its own reading. A new cell sitting at storage voltage — typically around 3.6V — sits below the panel's "full" threshold of approximately 3.85–4.1V. The fault clears on its own once the cell reaches float charge, usually within 24–48 hours of continuous mains power.