Fulham Hotspot 2 Emergency Light Replacement Battery 9.6V 800mAh

Fulham Hotspot 2 — 9.6V Ni-CD Replacement Battery (FHSBATT8-AA.9)

This is a 9.6V, 800mAh nickel-cadmium battery for the Fulham Hotspot 2 emergency lighting unit. It replaces OEM part FHSBATT8-AA.9 inside the fixture's backup power compartment. When the original cell degrades, this restores the unit's ability to activate and sustain illumination during a mains failure.

• Hotspot 2 cell pack compatibility: The Hotspot 2 charge controller expects a 9.6V Ni-CD cell pack at a specific float voltage range. Substituting a different chemistry or voltage disrupts the trickle charge circuit and triggers a permanent fault condition on the board.
• Bench tested on actual hardware: We ran this cell through a full charge cycle and simulated a mains drop. The BMS accepted the charge without fault, and the unit switched to battery mode without delay or LED error.
• First test cycle after installation: Hold the test button for the full rated duration within 24 hours of fitting this cell. This lets the charge controller register the new cell's capacity and clears any residual fault state before your next scheduled compliance inspection.

Charge indicator staying red after fitting a new FHSBATT8-AA.9 cell

A new Ni-CD cell ships in a partially discharged state. The Hotspot 2 charge controller uses float voltage to confirm the cell is within its acceptance window — a freshly unpackaged cell often sits below that threshold. The red LED is the controller refusing to enter float mode, not a sign of a faulty battery. Leave the unit on mains power for 24 hours; the cell voltage will climb into the acceptance range and the indicator should shift to green.

Emergency light dims and cuts out partway through a duration test

This happens when a new cell has not completed a full conditioning cycle before the test is run. Ni-CD cells need at least one complete charge-discharge cycle to reach rated capacity — 800mAh is not available on the first activation straight out of the box. If the light dims mid-test, return it to mains for a full 24-hour charge, then re-run the test from a fully charged state. A cell that still cuts out early after conditioning has a genuine capacity fault and should be replaced.