Nightstick XPR-5554G Headlamp Compatible Battery 3.7V 700mAh

Nightstick XPR-5554G Headlamp — 3.7V Li-Polymer Replacement Battery (5554-BATT)

This is the 3.7V, 700mAh lithium-polymer replacement battery for the Nightstick XPR-5554G headlamp. It replaces OEM part number 5554-BATT directly. When the original cell loses capacity after repeated charge cycles, this swap restores the headlamp to full rated output.

• XPR-5554G platform fit: The 5554-BATT cell is specific to this headlamp's internal battery bay — the 42.20 × 24.60 × 7.20mm LiPo form factor and connector orientation match the driver board's input circuit. No modification needed.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the XPR-5554G driver. The BMS held 3.7V nominal cleanly across all output modes and cut off at the correct low-voltage threshold without triggering false mode steps.
• Post-swap first charge: After fitting a new LiPo cell in the XPR-5554G, run a full charge before use. The headlamp's driver calibrates its fuel gauge to the new cell's capacity on that first full cycle — skipping it can cause the battery indicator to read inaccurately until the next full charge.

XPR-5554G output stepping down before the battery indicator hits low

The XPR-5554G's driver uses brownout protection to step down LED output when cell voltage drops below a set threshold — typically around 3.2V under load. This happens before the low-battery indicator triggers because the indicator reads resting voltage, not voltage under current draw. High output modes pull more current, which creates a larger voltage sag at the cell terminals. If the headlamp dims noticeably in turbo or high mode while the indicator still shows charge, the cell is near end-of-life and needs replacement.

Headlamp running noticeably shorter in turbo mode than expected

Turbo mode on the XPR-5554G draws significantly more current than standard or low modes — the 700mAh cell depletes faster because total watt-hours drawn per hour is much higher. This is normal behaviour, not a cell fault. If turbo runtime has dropped sharply compared to when the headlamp was new, the cell has likely lost usable capacity through age or shallow cycling. Check resting voltage after a full charge — a healthy 3.7V LiPo should read between 4.15V and 4.20V fully charged.