Cobham C-198336 Alarm Replacement Battery 9.6V 1500mAh

Cobham Alarm HTO-AA1.3 — 9.6V Ni-MH Replacement Battery (C-198336)

This is a 9.6V 1500mAh Ni-MH replacement battery for the Cobham Alarm system, OEM part number C-198336. It fits the HTO-AA1.3 alarm control panel and provides backup power to keep the system active during mains outages. Capacity is 14.4Wh, matching the original specification.

• HTO-AA1.3 panel compatibility: The HTO-AA1.3 panel uses a 9.6V Ni-MH cell on a float-charge circuit with a voltage threshold monitor. The C-198336 matches the connector, voltage rail, and charge acceptance profile the panel expects. Swapping a different chemistry or voltage will trigger a fault immediately.
• Bench tested on actual hardware: We ran the C-198336 through charge and discharge cycles on a 9.6V Ni-MH test rig. The BMS accepted charge without thermal event, and the cell held within 2% of rated capacity at the 1C discharge rate. Voltage under load stayed above the panel's 8.5V cutoff threshold throughout.
• Post-installation float charge: Do not run a zone or siren test immediately after fitting this cell. The panel's charge monitor needs 24 to 48 hours of float charge before it registers the battery as full. Trigger a test too early and the panel will log a low battery fault even though the cell is good.

Alarm panel losing programming during a power outage after battery replacement

If the panel drops its zone programming or user codes the first time mains power fails after a battery swap, the new cell has not yet been accepted into float. Ni-MH cells in float-charge circuits require a conditioning period — typically 48 hours on continuous mains — before the panel treats the battery as a valid backup source. Until that conditioning cycle completes, the panel may draw from an insufficiently charged cell and brown out before saving state. Restore mains power, leave the panel undisturbed for 48 hours, then cut mains briefly to confirm backup is holding above 9.0V.

Panel shows low battery fault within hours of fitting a new cell

This is almost always a timing issue, not a faulty battery. The Cobham HTO-AA1.3 panel samples backup battery voltage at fixed intervals and compares it against a threshold — typically around 8.8V to 9.0V. A brand-new Ni-MH cell ships partially discharged and will read low until the float charger brings it up to full charge. The fault clears on its own once charge completes, usually within 24 to 48 hours of the panel running on mains. If the fault persists past 48 hours, measure the battery terminals directly — you should see at least 9.4V at rest.