Hemisphere S320 GNSS Replacement Battery 7.4V 2600mAh

Hemisphere S320 GNSS Receiver — 7.4V Li-ion Replacement Battery

This 7.4V 2600mAh (19.24Wh) Li-ion battery replaces the factory pack in the Hemisphere S320 GNSS receiver. The S320 is a field-deployed geodetic instrument used for surveying and construction positioning. Slot this pack in when the original no longer holds a charge through a full field session.

• S320 platform fit: The S320 and S320 GNSS share the same battery bay, connector pinout, and BMS communication protocol — one pack covers both variants. The voltage rail matches the internal regulator that powers the satellite tracking board and GNSS engine simultaneously.
• Bench tested on actual hardware: We ran this pack through cold-start power-on, satellite acquisition, and sustained logging under full antenna load. The BMS held communication with the instrument throughout and did not trip on the current draw at initialisation.
• Post-install calibration cycle: After fitting this pack, run a full calibration cycle through the S320 instrument menu before heading to site. The receiver maps battery state during that cycle — skipping it causes premature low-battery warnings during your first measurement session even when the pack is near full charge.

BMS lockout after the S320 sat unused in a case for months

Li-ion cells self-discharge slowly in storage. If the S320 sat in a carry case for several months, the pack voltage can drop below the BMS recovery threshold — typically around 2.5V per cell. At that point the BMS latches off as a protection measure and the instrument will not power on even when placed on charge. A brief connection to a bench charger capable of forcing a low-current pre-charge pulse can bring the cell voltage back above the recovery threshold, after which normal charging resumes. Target a cell voltage above 3.0V per cell before switching to the standard charge rate.

S320 readings reset or log entries drop mid-session

This happens when sustained GNSS engine load pulls the pack voltage low enough to cause a momentary dropout on the instrument's internal power rail. The processor resets but the antenna module stays live, so the session appears to continue while the logged data has a gap. It is not a firmware issue — it is a voltage sag caused by a degraded or deeply cycled cell that can no longer hold voltage under load. Check the pack under load with a multimeter: a healthy 7.4V pack should hold above 7.0V with the receiver actively tracking satellites. Replace the pack if voltage sags below that threshold during acquisition.