YSI ProDSS 626846 Replacement Battery 3.7V 5200mAh

YSI ProDSS / ProSolo Series — 3.7V Li-ion Replacement Battery (626846)

This is a 3.7V Li-ion 5200mAh battery for the YSI ProDSS multiparameter water quality instrument and the ProSolo Digital Water Quality Meter. It also fits the 626870-1 and 626870-2 variants. The OEM part numbers covered are 626846 and 626840 Rev B.

• ProDSS and ProSolo platform fit: These models share the same battery bay geometry, connector pinout, and BMS handshake protocol. The instrument reads pack state through the same communication line, so one cell format serves the full platform without modification.
• Bench tested on actual hardware: We ran this pack through the ProDSS power-on sequence and monitored BMS behaviour during multi-probe initialisation. The BMS held stable through the current spike at sensor power-up and passed the instrument's internal pack recognition check without fault codes.
• Post-install calibration before first field deployment: After fitting this battery, run a full calibration cycle through the ProDSS instrument menu before taking it into the field. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings to appear during your first measurement session, even with a full charge.

Probe module current spike tripping BMS on sensor initialisation

When the ProDSS powers up its probe modules — particularly dissolved oxygen and conductivity sensors — the combined inrush current can exceed the BMS overcurrent threshold on a degraded or undersized cell. The instrument interprets this as a fault and cuts power before the first reading is logged. This pack's cells are rated to handle the initialisation surge without tripping the protection circuit. If you still see a shutdown at sensor power-up, check whether the cable and connector between the sonde and handset are seated fully — a partial connection raises contact resistance and amplifies the draw spike.

Pack will not charge and shows no response after months unused in a carry case

Li-ion cells that sit unused for an extended period self-discharge below the BMS recovery threshold — typically around 2.5V per cell. Below that point, the BMS enters sleep mode and blocks the charge circuit as a protection measure, so the charger sees no load and the instrument shows nothing. Place the pack on the YSI charger and leave it connected for at least 60 minutes without interruption — most chargers apply a low-current trickle to bring the cell voltage back above the recovery threshold before switching to full charge. If the charge indicator still does not activate after 90 minutes, measure the pack terminal voltage directly; anything below 2.8V indicates the cell has dropped too far to recover safely and the pack needs replacing.