About this replacement
Cobra 5370 / 6422 Alarm Sounder — 7.2V Ni-MH Replacement Battery (GP60AAH6YMX)
This 7.2V 600mAh Ni-MH battery replaces the GP60AAH6YMX cell pack in Cobra 5370 and 6422 alarm sounders. It fits both the standard and alarm sounder variants of each model. Capacity figures come from the product data — 600mAh, 4.32Wh.
- 5370 and 6422 sounder compatibility: Both models share the same battery bay dimensions and voltage rail. The GP60AAH6YMX cell pack fits either unit without modification to the connector or housing.
- Bench tested on actual hardware: We cycled this battery through siren activation loads on a 7.2V Ni-MH test rig. The cell pack held stable output voltage across multiple activation bursts without dropping below the minimum siren trigger threshold.
- Tamper switch check after installation: Once the battery is seated, close the siren cover completely and confirm the tamper switch clicks into its engaged position. Outdoor Cobra sounders report a tamper fault to the alarm panel if the cover is not fully latched — some panels log this as a battery error, which causes unnecessary callouts.
Why the Cobra 5370 siren cuts out before the alarm cycle ends
The 5370 sounder draws a sharp current spike at activation to drive the siren tone. A Ni-MH cell that has not completed an initial charge cycle after a long shelf period cannot sustain that draw for the full alarm duration. The BMS interprets the voltage sag as a depleted pack and shuts the output early. Allowing a full 24-hour charge via the panel before the first alarm test resolves this in most cases.
Siren battery reading as low charge immediately after fitting a new cell
Ni-MH cells lose charge during storage — a new battery sitting in a warehouse for several months can arrive at 40–50% of rated capacity. The alarm panel reads state-of-charge on the first poll and flags it as low. This is not a faulty battery. Connect the panel to mains, leave the sounder on charge for 24 hours, then re-run a zone test. The panel should clear the low-battery event once the cell reaches 7.8–8.0V resting voltage.