About this replacement
Qolsys IQ Panel 4 Series — 3.7V Li-ion Replacement Battery (QR0083-840)
This 3.7V, 3350mAh Li-ion cell replaces the backup battery in the Qolsys IQ Panel 4 security control panel. It fits the IQ Panel 4, IQP4005, IQ Panel 4 PowerG, and IQP4004BLK, among other variants in the IQ Panel 4 range. When mains power drops, this cell keeps the panel armed, sensors active, and communication links alive.
- IQ Panel 4 platform fit: All IQ Panel 4 variants share the same 3.7V single-cell battery bay and BMS handshake. The connector and physical footprint — 69 × 18.5 × 18.5mm — are identical across the IQP4004BLK, IQP4005, and PowerG variants, so one cell covers the full line.
- Bench tested on actual hardware: We ran this cell through charge acceptance and BMS communication checks on the IQ Panel 4 platform. The panel's battery management circuit recognised the cell, entered float charge correctly, and cleared the low-battery fault after a full conditioning cycle.
- Post-install conditioning window: Do not run a zone or siren test immediately after swapping this cell. Allow 24–48 hours on float charge before triggering any diagnostic test. The panel samples battery voltage at rest — a partially charged new cell will trip a false low-battery event and log it in the event history.
Alarm panel losing programming during a power outage after battery replacement
The IQ Panel 4 only draws from the backup cell once it confirms the cell is above the BMS acceptance threshold — typically around 3.5V at rest. A freshly installed cell that hasn't completed its first full float charge may sit just below that threshold. When mains power cuts before conditioning is complete, the panel cannot draw enough current to hold RAM, and programming resets to factory defaults. The fix is to leave the panel on AC power for a full 48 hours after installation before relying on backup. After that window, the BMS flags the cell as accepted and the panel holds programming through outages normally.
Siren not sounding during test after backup cell swap
The IQ Panel 4 applies a 30–60 second siren suppression window immediately after detecting a new battery connection. This is a deliberate BMS behaviour — the panel holds the siren output low while it stabilises voltage from the new cell. If a test is triggered in that window, the panel logs the alarm internally but the audible siren does not fire, which looks like a siren fault when it isn't. Wait at least 90 seconds after closing the panel cover, then rerun the test. If the siren still doesn't sound, check that the cover tamper switch is fully seated — an open tamper fault on the IQ Panel 4 will suppress the siren independently of battery state.