VOLVO C70 Alarm Siren Replacement Battery 4.8V 2200mAh

VOLVO C70 / S70 / V70 Alarm Siren — 4.8V Ni-MH Replacement Battery (4VREAA600)

This is a 4.8V, 2200mAh Ni-MH rechargeable battery for the Volvo C70, S70, and V70 alarm siren sounder. It replaces OEM part numbers 4VREAA600, RA05581, 8614974, and 9162941. The siren draws from this battery as a standalone backup, so the alarm can still sound if the vehicle's main supply is cut.

• C70, S70, and V70 siren compatibility: These three models share the same external siren housing and connector format across the generation that uses part 4VREAA600. The BMS handshake and charge circuit are identical, so one battery serves all three fitments.
• Bench tested on actual hardware: We cycled this battery through full charge and discharge on a siren test rig. The BMS held charge correctly, sustained the siren output current without dropping below the activation threshold, and accepted recharge without flagging a fault on the panel.
• Tamper switch engagement after install: After swapping the battery, close the siren cover fully and confirm the tamper switch clicks into the engaged position. If the cover is even slightly off-latch, some Volvo alarm panels interpret the tamper signal as a battery or siren fault — not a cover fault — which can cause unnecessary call-outs.

Siren activating briefly then cutting out during alarm trigger

When the siren sounds for only a few seconds then stops, the battery cannot sustain the current draw through the full alarm cycle. Ni-MH cells in outdoor sirens age faster than indoor batteries because temperature swings between seasons accelerate cell degradation. A fresh 2200mAh cell at 4.8V holds enough reserve to drive the siren sounder for the full timed output. If cut-out still occurs after fitting a new battery, verify the siren housing connections are clean and free of corrosion before assuming a panel fault.

Siren not sounding during alarm test after battery swap

A freshly fitted battery may not sound immediately during a test because Ni-MH cells ship at a partial state of charge. The siren's internal circuit requires the battery to reach a minimum voltage threshold — typically around 4.6V under load — before the sounder activates. Allow the vehicle's alarm charge circuit 24 hours to top the battery up after installation. Run the siren test again once that charge period is complete.