Fulham HotSpot FHSCP-UNV-10P-L-SD Compatible Battery 9.6V 3600mAh

Fulham HotSpot FHSCP-UNV-10P-L-SD — 9.6V LiFePO4 Replacement Battery (IFR18650E 3S2P)

This is a 9.6V 3600mAh LiFePO4 replacement battery pack for the Fulham HotSpot FHSCP-UNV-10P-L-SD emergency lighting fixture. It restores emergency backup function to units that have lost capacity or failed to hold charge. The 3S2P 18650 cell configuration matches the original pack's voltage rail and charge controller requirements.

• FHSCP-UNV-10P-L-SD compatibility: The FHSCP-UNV-10P-L-SD uses a trickle-charge controller calibrated for a 9.6V LiFePO4 float voltage. Swapping to a Li-ion pack at the same nominal voltage will cause the charge controller to apply incorrect float current, accelerating cell degradation. This pack keeps the chemistry match correct.
• Bench tested on actual hardware: We cycled this pack through a full charge and load discharge on the FHSCP platform. The BMS accepted charge without fault flags, and the cell voltage settled at the expected LiFePO4 float level. No thermal events or protection trips occurred during the test cycle.
• First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This lets the charge controller register the new pack's capacity before a scheduled compliance test. A pack that has sat in storage may not reach rated capacity on its very first activation without this conditioning cycle.

Charge indicator staying red after fitting the new battery

After sitting in a warehouse, a fresh LiFePO4 pack typically rests at 3.0–3.1V per cell — below the float acceptance window the FHSCP charge controller expects to see. When the controller reads an incoming voltage outside its acceptance threshold, it holds the fault or charging LED red rather than transitioning to green. Leave the fixture on mains power for a full 24-hour charge cycle before drawing any conclusions about a fault. If the LED stays red past 24 hours, measure the pack voltage at the connector — it should read between 9.6V and 10.8V for the controller to register a healthy state.

Emergency light dims or cuts short during a duration test

A pack that has not completed at least one full charge cycle before the test will not deliver its rated 3600mAh to the load. LiFePO4 cells fresh from storage can take one full charge-discharge cycle to reach full capacity — the charge controller in the FHSCP needs to complete that initial float cycle uninterrupted. Running a duration test too soon after installation draws the pack down before it has been fully conditioned, making the light dim or trip the low-voltage cutoff early. Charge for 24 hours on mains, then run a full manual test to confirm the pack holds the load for the rated duration.