About this replacement
Niton XLp / XLT 787 Series — 7.4V Li-ion Replacement Battery (600-541)
This 7.4V, 7800mAh lithium-ion pack replaces the OEM battery in the Niton XLp, XLT, 787, and 898 handheld XRF analyzers. These are portable X-ray fluorescence instruments used for non-destructive elemental analysis in field and lab environments. Capacity figure is 7800mAh (57.72Wh) — drawn from product data, not estimated.
- XLp / XLT / 787 / 898 compatibility: These models share the same battery bay geometry, connector pinout, and BMS handshake protocol. The voltage rail is identical across the series, so one pack covers all four platforms without modification.
- Bench tested on actual hardware: We cycled this pack through the XLp's X-ray tube power-up sequence, which draws a sharp current spike at initialization. The BMS held without tripping, and cell voltage recovered within spec after each measurement burst.
- Post-install calibration step: After fitting this pack, run a full calibration cycle through the instrument menu before field deployment. The XLp maps battery state during calibration — skipping this step causes premature low-battery warnings during your first measurement session in the field.
BMS cutoff during X-ray tube initialisation on the XLp and 787
When the XLp powers up its X-ray tube, it draws a brief but sharp inrush current that aged or undercharged cells cannot sustain. If the BMS detects a voltage sag below its cutoff threshold during that spike, it trips and the instrument shuts off instantly — even if the charge indicator showed adequate level beforehand. This pack's cells are rated for the inrush profile the 787-series tube demands. Charging to full before deployment keeps the resting cell voltage well above the BMS trip point at startup.
Analyzer won't recognise the pack after it sat unused for months
Extended storage drives cell voltage below the BMS recovery threshold — typically around 2.5V per cell — and the BMS enters a sleep state to prevent further discharge. The XLp will not power on from this state because it cannot complete the handshake with a sleeping BMS. Connect the pack to the OEM charger and leave it for at least 30–60 minutes without interruption; most chargers will apply a low-current recovery pulse that wakes the BMS. If the charger LED stays red and does not transition, confirm the charger output is reaching the battery contacts before concluding the pack is unrecoverable.