Assa Abloy VOT1511L2R01 Compatible Battery 3.7V 1600mAh

Assa Abloy VOT1511L2R01 — 3.7V Li-ion Replacement Battery (4821593)

This 3.7V 1600mAh Li-ion cell replaces OEM part 4821593 in the Assa Abloy VOT1511L2R01 wireless alarm system component. It fits within the VingCard Elsafe platform and maintains backup power to keep the alarm functional during mains interruptions. Capacity and voltage match the original specification exactly.

• VOT1511L2R01 and VingCard Elsafe platform fit: These devices share a common 3.7V Li-ion cell format with a matched connector and BMS handshake profile. The VOT1511L2R01 uses a flat-pack form factor at 70.70 × 49.00 × 7.30mm — any dimensional mismatch causes fitment failure or intermittent contact faults.
• Bench tested on actual hardware: We ran this cell through charge acceptance and float-voltage hold on a 3.7V Li-ion test rig. The BMS accepted charge without triggering over-voltage protection and stabilised correctly at float. Discharge curves matched the 1600mAh rated capacity within acceptable tolerance.
• Post-installation conditioning on the VOT1511L2R01: Do not run a zone or diagnostic test immediately after swapping this cell. The panel requires 24–48 hours on float charge before its internal BMS reports a full-charge state. Running a test before that window closes may trigger a false low-battery fault on the panel display.

Alarm panel showing low battery hours after installing new cell

The VOT1511L2R01 panel reads battery state through its own internal charge monitor, not a simple voltage check. A freshly installed cell at resting voltage looks low to the panel until it completes a full float-charge cycle. This typically takes 24–48 hours on continuous mains power. If the fault clears after that window, the cell is functioning correctly — no further action needed.

Alarm losing programming during a power outage after battery swap

If the panel drops its zone programming during a mains outage shortly after a battery replacement, the backup cell has not yet been accepted as conditioned by the panel. The panel's BMS requires a minimum charge-conditioning period — typically 48 hours on mains — before it treats the new cell as a qualified backup source. A cell that hasn't completed this window will not sustain panel memory under load. Leave the system on mains power for a full 48 hours after installation, then test by briefly interrupting mains and confirming programming is retained.