About this replacement
Ring Alarm Keypad (5AT2S7) — 3.7V Li-Polymer Replacement Battery (PCM2000)
This 3.7V, 2000mAh Li-Polymer cell replaces the factory battery in the Ring Alarm Keypad (model 5AT2S7). It slots into the keypad's rear battery compartment and connects via the original JST-style lead. Voltage and capacity match OEM spec exactly — 3.7V nominal, 7.4Wh.
- Ring Alarm Keypad 5AT2S7 fit: The 5AT2S7 keypad uses a single flat Li-Polymer pouch cell on a 3.7V rail. The PCM2000 shares the same 86.80 × 39.20 × 4.50mm envelope and connector orientation, so the cell seats without modification and the onboard BMS handshake completes normally.
- Bench tested on actual hardware: We cycled this cell through charge, float, and simulated mains-loss events on the keypad. The protection circuit engaged correctly at low-voltage cutoff and the panel resumed normal arming and status functions after recharge.
- Post-swap charge conditioning: After fitting this cell, leave the keypad on mains power for 24–48 hours before running any diagnostic or zone test. The panel's charge controller needs this window to bring the pouch cell to full float voltage — short-cutting it causes the panel to flag a low-battery fault even on a healthy new cell.
Why the Ring Keypad 5AT2S7 reports low battery hours after a new cell is fitted
The 5AT2S7 samples battery voltage through its onboard charge controller, not at the cell terminals directly. A freshly installed pouch cell ships at storage charge — typically 3.6–3.7V — which sits below the panel's "full" threshold of around 4.1–4.2V. The controller interprets this as a degraded or low battery and raises the alert. No fault exists with the cell itself; the panel needs 24–48 hours on mains power to charge the cell fully and clear the status flag automatically.
Alarm losing programmed zones after a mains outage with the new battery installed
If the keypad loses its zone configuration during a power cut shortly after a cell swap, the backup battery had not yet reached a charge level sufficient to sustain the panel's memory and processor during the outage. The 5AT2S7 requires the backup cell to hold above approximately 3.8V under load to maintain volatile settings. Install the new cell, restore mains power, and allow a full 48-hour conditioning period before testing backup operation. After that window, trigger a brief mains-loss test — the panel should hold all programming through the outage.