Siglent SHS800 Replacement Battery 7.4V 5000mAh Li-Polymer

Siglent SHS800 / SHS1000 — 7.4V Li-Polymer Replacement Battery (BATT-SHS800)

This 7.4V 5000mAh (37Wh) Li-Polymer pack replaces the original battery in the Siglent SHS800 and SHS1000 handheld spectrum analyzers. These instruments are used for field RF measurements, wireless signal troubleshooting, and spectrum monitoring away from mains power. When the original cell degrades, this pack restores portable operation at the correct voltage and capacity.

• SHS800 and SHS1000 shared platform: Both models run the same 7.4V power rail and use an identical physical footprint and connector pinout, which is why they share one battery part number across the range.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the SHS800 platform. The BMS handled probe initialisation current spikes without tripping, and the instrument accepted the pack without throwing a battery fault flag.
• Post-install calibration on the SHS800/SHS1000: After fitting this pack, run a full calibration cycle through the instrument's system menu before heading into the field. The SHS800 maps battery state during that routine — skipping it causes the low-battery warning to fire early on your first measurement session, even with a full charge.

SHS800 shutting down mid-sweep during extended spectrum logging

During a continuous sweep or long logging session, the SHS800 sustains a higher current draw than during idle or single-shot measurements. If the cell has age-related internal resistance, the voltage sags under that load and can cross the BMS cutoff threshold before the displayed percentage reaches zero. The instrument shuts off abruptly — not a firmware crash, but a hardware protection event. A fresh pack with lower internal resistance holds the voltage rail stable under sustained sensor load and prevents these mid-session cutoffs.

SHS800 not recognising a new pack after the instrument sat unused for months

Li-Polymer cells self-discharge in storage, and if the pack drops below approximately 2.5V per cell, the BMS enters a deep-sleep lockout state to prevent further discharge damage. When you install the pack and press power, the instrument shows nothing — no boot screen, no fault message. Connect the instrument to its charger and leave it for 15–20 minutes before attempting to power on; the charger delivers a trickle current that brings the cell voltage above the BMS recovery threshold, typically around 3.0V per cell, at which point normal charging resumes.